AT-BOT_E120703

Robo-Creator : AT-BOT ctivity book  1

AT-BOT The 4-wheel autonomous robot programmed with C/C++ language Activity book

2Robo-Creator : AT-BOT activity book

AT-BOT activity book All rights reserved under the Copyrights Act B.E. 2537 Do not copy any part of this book without our permission

Who should use this handbook?

1. Students and other people who are interested in applying to microcontrollers for testing working process of automatic system or people who are fascinated in learning and examining the microcontrollers in new approaches such as using an autonomous robot as a form of an interactive media.

2. Academic institutes such as schools, colleges and universities, where provide electronic subjects or electronic and computing engineering departments.

3. Lecturers and teachers who would like to study and prepare lesson plans for microcontroller courses, including applied science which focuses on integrating electronics, microcontrollers, computer programming and scientific examination in high school education, vocational education, and bachelor’s degree.

Published and distributed by Innovative Experiment Co.,Ltd. 108 Soi Sukumvit 101/2 Sukumvit Road, Bangna, Bangkok 10260 THAILAND

Details and illustrations used in this handbook are thoroughly and carefully to provide the most accurate and comprehensive information under the conditions and time we have before publishing. Innovative Experiment Co.,Ltd. shall not be responsible for any damages whatsoever resulting from the information of this book as constant revisions and updates will be published after this edition.

Robo-Creator : AT-BOT ctivity book ď Źď€ 3

Clarification from writer/ complier team All Illustrations and Technical information found in this handbook are in our best interest to simplify working processes and equipment principles so that it could be easily understood by any user interested in robotics.

Therefore, The translation from THAI language to English and the usage of technical terms may not follow the provision of the Royal Academy where they are many words not described officially. Our team would be allowed to produce new technical terms.

The main reason of this explanation comes from data collection of equipment in embedded computer system and robotic technology. Thai language is quite hard to translate into English and thus our writer team gathered the required data and investigated to make sure that the understanding in working processes has the limited error.

When we com pose the information in Thai, many technical terms have complicated m eanings. Definition of vocabul ary occurred from the practice coordinated with linguistic meaning. If there are any errors or mistakes shown, the team of writer will accept and if we get explanation or suggestion from any expert, we will clarify and improve those errors as soon as possible.

In order to develop the academic media especially with new technological knowledge, it will be able to proceed continually under the participation of experts in all fields.

Innovative Experiment Co.,Ltd.

4Robo-Creator : AT-BOT activity book

Table of contents Chapter 1

AT-BOT : The 4-wheel autonomous robot………..................................…....……5

Chapter 2

AT-BOT Development tools..............................................................…………….17

Chapter 3

Wiring IDE introduction....................................................................…………….23

Chapter 4

ATX Library file..................................................................................……………..35

Chapter 5

The ATX controller board hardware experiment.....………………….....……49

Chapter 6

AT-BOT movement..............……..........................................………………………79

Chapter 7

Object avoiding by contact...……………………………...……………………..93

Chapter 8

AT-BOT Line tracking.........................…………………....................................….105

Chapter 9

AT-BOT with touchless object avoiding..........................................…………..147

Chapter 10

AT-BOT with Servo motor .....................................................…………………….155

Robo-Creator : AT-BOT activity book ď Źď€ 5

Chapter 1 AT-BOT : The 4-wheel autonomous robot AT-BOT (All-Terrain mobile robot) is an autonomous robot performed by DC motors with the set of 4 DC motor gearboxes come with spiked wheels in order to aid passing through rough surface more efficiently. Also, it can move up on the slope in the level of 0 to 25 degree and if it is necessary to stop immediately to change the direction of motion, it can do. The possibility is that AT-BOT is capable of supporting any mission in either a smooth competition court with lines appeared for determining directions of motion or rough court with barriers or participating with the World RoboCup Junior-Rescue.

Programming development of AT-BOT robots uses C/C++ language in the open source software are named Wiring (www.wiring.org.co).

AT-BOT controller boad is called ATX board, which is able to drive 6 of DC motors and 6 of Servo motors together. It has many ports for interfacing with both digital and analog sensors, basic digital outpuit port and using the data communication via 2 lined bus system called I2C bus and the standard UART serial bus.

The main driving system is consisted of 4 DC motor gearboxes with spiked wheels.

This results the AT-BOT with four-wheel automatic robot has a high driving power and high speed. It identifies that this is a presentation of the different robot driving system from the old system for studying.

AT-BOT is one of the robotic activities of Robo-Creator, the robotic kit for creative education.

6 Robo-Creator : AT-BOT activity book

1.1 AT-BOT part list 1. ATX controller board 2. USB-miniB cable 3. Light reflector (ZX-03R) 4 sets 4. Touch sensor (Switch input boards) 2 sets 5. BO-1 DC motor gearbox 48:1 ratio with mounting and cable 4 sets 6. Standard servo motor x 1 7. Spike wheel sets (diameter 65mm., width 26mm. also include the hub for BO-1 gearbox) 4 sets 8. 5-AA battery holder with wire 9. Plasitc joiner set and Strip joiner set 10. Right angle metal shaft set 11. Nuts and screws set 12. CD-ROM (software, example code and documentations) 13. Activity manual and construction sheet 14. Line tracking demonstration paper

1.2 ATX controller board features In the figure 1-1, it is shown components of the ATX controller board and there are significant technical features as follows:  Main microcontroller is Atmel’s ATmega128. It features 8-ch 10-bit Analog to

Digial Converter, 128-KByte Flash memory , 4-KByte EEPROM, 4-KByte RAM. Operated with 16MHz clock from external crystal  Define all ports compatible with Wiring I/O standard hardware (www

.wiring.org.co). The number of port are 0 to 50.  13 programmable port in JST connector type. Includes Digital I/O port (2 :

port 14 and 15), A/D port (7 : port 40/ADC0 to port 46/ADC6), Two-wire interface or TWI (2 : port 0/SDA and port 1/SCL) and UART serial port communication (2 : port 2/RX1 and port 3/TX1). Both TWI and UART ports can config to digital input/output port for more I/O applications.  Analog input (ADC0 to ADC6) supports 0 to +5Vdc input. The converter

resolution is 10-bit. The result value is 0 to 1,023 range.

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 One variable resistor is connected with the Analog input ADC7 of main

microcontroller for simple ADC experiment.  2 of button switches with resistor pull-up are connected with port 49 and 50 of

the Wiring I/O controller board for simple digital input experiment.  One LED with a current limited resistor. It is connected with port 48  One piezo speaker at port 4  16x2 characters LCD for monitoring  On-board digital compass; HMC6352 from Honeywell. It is interfaced by I2C

bus or TWI  UART port for interfacing serial module device such as camera module (ZX-

CCD, CMUCAM1, CMUCAM2, mCAM), servo controller board (Parallax servo controller, ZX-SERVO16U), Real-time clock (ZX-17 : serial real-time clock moduel)  6-ch DC motor driver with indicators. Support 4.5V to 9V DC motor. Maximum

current output 3A and 1.2A continuous.  6-RC servo motor output; support 4.8 to 7.2V standard and continuous servo

motor types.  Motor driver power indicator; nomally turned on. It will off when motor is short-circuit.

42 ADC2

41 ADC1

40 ADC0

46 ADC6

45 ADC5

44 ADC4

4

43 ADC3

 5

    

START

 



C r e a t o r e > >> > > > > > 3

c o n t r o l l er R b o a r d USB DATA

ON TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

1

E2

SW1

49

SW2

50

 

48

0

ADC7

SERVO PORT 9

BATTERY LEVEL

10 11 12 13 S

8

+

-



KNOB

RESET

7.2-9V BATT.



 

2

 

 

 

14

PC6

15 PC7

MOTOR

      

Figure 1-1 : ATX controller board layout



8 Robo-Creator : AT-BOT activity book

 5-status battery level monitor circuit :

- Last left yellow LED displays that the input supply voltage is 6.75V. When the battery voltage is lower than 6.75V, this LED will start to blink.

- Next yellow LED displays the input supply voltage at 7.0V. - First green LED displays the input supply voltage at 7.25V. - Second green LED displays the input supply voltage 7.5V. - Last right green LED displays that the input supply voltage is higher than at 7.75V.  Download and interface with computer via USB port by using USB to UART

converter chip; FT232RL. USB connection indicator is available.  Set the operation by Mode/Reset switch  Supply voltage range +7.2 to +9V 2400mA for 4 motor loads.  2 voltage regulator on-board; +5Vdc for microcontroller and all digital circuit,

+6Vdc for all motor driver circuits. By using voltage regulator; the motor driver circuit can drives DC motor with constant speed when battery voltage is full and reduce to 60%. It features constant speed without effect by battery voltage until it is lower 60% of full.

Robo-Creator : AT-BOT activity book  9

1.3 Output device features 1.3.1 DC motor gearbox DC motor gearbox of Robo-Creator kit is the BO1 model. The technical features are as follows :  Requires the supply voltage +4.8 to +9Vdc 130mA @6V and no load  Gear ratio 48:1  Speed 250 round per minute @6V and no load  Weight 30 gram  Torque 0.5kg.-cm.

Driver gear (2) 9 teeth Driver gear (1) 8 teeth

Driver gear (4) 17 teeth

Driver gear (3) 17 teeth

Follower gear (3) Follower gear (1) 28 teeth 36 teeth Follower gear (4) Follower gear (2) 28 teeth 36 teeth

Figure1-2 : Details and gear diagram of BO-1 DC motor gearbox

10 Robo-Creator : AT-BOT activity book

1.3.2 Standard servo motor Servo motor has 3 wires; Signal (S), Supply voltage(+V) and Ground (G) The technical features is as follows :  Requires the supply voltage +4.8 to +6Vdc  Weight 45 gram  Torque 3.40kg-cm. or 47 oz-inches.  Size (width x length x height) 40.5 x 20 x 38 mm. or 1.60 x 0.79 x 1.50 inches.

(A)

(B)

(C)

Figure 1-3 : Details of standard RC servo motor of Robo-128 (A) outside body

(B) Gear system

(C) Electronic circuit board

1.4 Sensor features 1.4.1 Touch sensor/Switch input board The circuit is shown in the figure 1-4 including a switch with a LED and considered output as logic ‘0’ when switch is pressed.

If the switch is pressed : the logic ‘0’ will be sent and the red LED is on.

If no press : LED is off and the logic is ‘1’.

LED1

+V R2 10k

R1 510

S1 Switch

R3 220

DATA

GND

Figure 1-4 : The touch sensor or Switch input board picture and schematic diagram

Robo-Creator : AT-BOT activity book  11

Output port

LED

LED1

+V OUT

SFH310

GND

10k

220

Light reflection sensor

Figure 1-5 : Light reflector sensor layout andshcematic diagram

1.4.2 The light reflection sensor : ZX-03R The circuit and layout of this sensor are displayed in the figure 1-5. The circuit is used to detect the reflected lights from surface or lines.

During apply the power supply, the red LED is bright at all the time. Meanwhile, the light receptor is SFH310 photo-transistor and it will get red lights from the reflection of objects or surface. The amount of the reflected light will be more or less depending whether there is an obstacle or not and how well the object can reflect red light. The reflection of red lights is based on the surface texture and colour of objects. It is said that the white smooth objects are able to reflect light well so the infrared receptor gets a lot of reflected light and the output voltage will be high. As black objects reflect less light, the light receptor sends low voltage. With such features, the sensor circuit board is often used to trap the reflected light on the surface and lines. It is necessary to install the circuit at the lower part of a robot.

With the use of red light as a main light to detect, this allows the sensor to measure the colour difference on the surface printed by IR or UV resistant ink.

Due to ZX-03R light detection circuit gives the result as DC voltage, applying on ATBOT robot has to connect the signal to 7 channels of analog input on the ATX controller board, from ADC0 to ADC6. After reading the analog signal value, use this value to check the value on reflected light detection circuit and then apply to detect lines.

1.4.3 GP2D120 module detecting distance with Infrared GP2D120 is a module that detects distance with Infrared and with the packet of 3 extension parts, including 3 pins; +Vcc, GND and Vout. Reading voltage value from GP2D120 must do after the preparation period of the module, which takes 32.7 to 52.9 millisecond (1 millisecond equal 0.001 second). So reading the value should wait for the suitable time as mentioned above and shown the basic data in the figure 1-6.

Output voltage of GP2D120 at the distance of 30 centimetres, the power supply at +5V as in the range of 0.25 to 0.55V has the mean as 0.4V and the range of output voltage change at the distance of 4 centimetres is 2.25V±0.3V.

12 Robo-Creator : AT-BOT activity book

Infrared LED transmitter

Output voltage (V)

Infrared Receiver

2.8 2.4 2.0

GP2D120

1.6 1.2

Vout GND

Vcc 0.8 0.4

Supply

0 38.3ฑ9.6 ms

0

4

8

12

16

20

24

28

32

Distance (cm) Measurement

Vout

1st measure

2nd measure

Not stable

1st output

n measure

2nd output

n output

5 ms

* Use Kodak R-27 gray-white paper.

The white side has a 90% reflection rate, made from a material that reflects light for range measurement.

How to measure distance The infrared light is sent out from a transmitter to the object

Object

in front, by passing through a condense lens so that the light intensity is focused on a certain point. Refraction occurs once the light hits the surface of the object. Part of the refracted light will be sent back to the receiver end, in

L

which another lens will combine these lights and determine A

the point of impact. The light will then be passed on to an array of photo-transistors. The position in which the light falls can be used to calculate the distance (L) from the transmitter to the obstacle using the following formula:

L F  A X

F Transmit LED

GP2D120

Therefore, L equals

L

Photo array

X

FA X

Thus, the distance value from the phototransistors will be sent to the Signal Evaluation Module before it is changed to voltage, resulting in a change of voltage according to the measured distance.

Figure 1-6 : shown shape, arrangement of pins, diagram of time of operation, and graph shown the operation of GP2D120 sensor

Robo-Creator : AT-BOT activity book ď Źď€ 13

1.5 Mechanical compoments 1.5.1 Plastic wheels for BO-1 DC motor gearbox and rubber tire A circular wheel has the diameter of 65 millimeters. It is able to fit with the axis of BO1 gear motor directly without any additional modification and tighten with a 2 mm tapping screw. A wheel tire is made up of rubber and its texture has treads in order to enhance in sticking over the surface.

1.5.2 Spike wheel The wheels are unique. The wheel surface is rubber and has triangular buttons with rounded end and thorn-like protrusions to aid in adhesion and movement across smooth surface, rugged surface, slope or zippers with the slope less than 20 degree.

To install this kind of plastic wheels with the axis of the gear motor of model BO-1 will be required to use special joints to help and attach with a screw and 3 mm nuts.

1.5.3 Track and wheel set It is a track set constructed for track with wheels or crawler track with wheels in different sizes and it is compatible with a plate set. The set includes tracks with 30 joints (2 pieces), 10 joints (4 pieces), 8 joints (4 pieces), driving wheels (2 pieces), large support wheels (2 pieces), medium support wheels (10 pieces), poly caps (12 pieces), stainless axis with the diameter of 3 mm, length of 110 mm (4 pieces) and necessary screw set.

14ď€ ď Źď€ Robo-Creator : AT-BOT activity book

1.5.4 Base plate and Plate set It is a multi-purpose material set for making the base or the chassis frame. The set provides plastic plates produced from 2 types of ABS materials. The first type is called ATplate in black and the other is a plate with the size of 160 x 60 mm. There are holes on the plates and each hole is 3 mm in size and they are seperated by 5 mm in distance and the total holes are 341. The set also contains brackets for long axis (2 pieces), brackets for short axis (2 pieces) and a screw set necessary for fastening.

1.5.5 Grid plates Plates are plastic manufactured from ABS materials in the size of 80 x 60 mm and 80 x 80 mm each. Each hole has the size of 3 mm and the distance between each hole is 5 mm.

1.5.6 Plastic joiners They are stiffed plastic components and there are three designs, including, straight joiners, right angle joiners, and obtuse angle joiners. Each piece can be inserted together and they are used to construct a decorated structure (or decoration). A set contains all three types, available 5 colors and 4 pieces for each, and 60 pieces in total.

Robo-Creator : AT-BOT activity book ď Źď€ 15

1.5.7 Plastic strip joiners They are rigid and tough and there are holes in the size of 3 mm for each piece for installing or connecting with other structure components by a screw. At the end of each rod can insert with plastic joiners. There are three different sizes including 3, 5 and 12 holes and each size has 4 pieces in a set.

1.5.8 Metal angle bar Metal angle bars are metal components with the width of 7.5 mm and they are cut into the right angle shape. There are holes with the size of 3 mm for using a screw to install or construct with other structure parts. Three different sizes are provided in a set, including 1x2 holes, 1x2 holes, and 2x5 holes and each size contains 4 pieces.

1.5.9 Screws and nuts Screws and nuts are equipment for fastening many components together. They compose of 2 mm-tapping screws (4 pieces), 3x8 mm-tapping screws (4 pieces), 3x10 mmtapping screws (30 pieces), 3x15 mm-tapping screws (4 pieces), 3x40 mm-tapping screws (4 pieces), 3x8 mm-flat head screws (4 pieces), 3x5 mm-hand driven screws (4 pieces), 3x20 mm-hand driven screws (2 pieces), and 3 mm-nuts (30 pieces).

1.5.10 Metal stands-off This kind of materials helps to hold different components together and support boards, grid plates and base plates. They are made of rustproof nickle-plated metal and have a characteristic of cylinder with the length of 25 mm. Inside of a cylinder, there is a spiral hole along its body for a 3 mm-screw to fasten and 3 poles are provided in a set.

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1.5.11 Plastic stands-off Plastic stands-off help fasten different parts and prop up boards, grid plates, and base plates. They are made from cohesive ABS plastic but able to be cut. The shape of the rod is cylindrical and there is a hole throughout the rod to insert 3 mm-screws. You can get different sizes and number of support poles, including, 3 mm. (4 pieces), 10 mm. (4 pieces), 15 mm. (4 pieces), and 25 mm. (4 pieces) in the set.

1.5.12 5-AA Battery holder It is used to carry 5 AA batteries. There is a wire which connects the anode and the cathode to the main controller board immediately.

1.5.13 JST3AA-8 cable This is an INEX standard cable, 3-wires combined with 2mm. The JST connector is at each end. 8 inches (20cm.) in length. Used for connecting between controller board and all sensor modules in the Robo-Creator kit. The wire assignment is shown in the diagram below.

2mm. pitch GND S +5V

2mm. pitch GND S/Data +5V

Robo-Creator : AT-BOT activity book  17

Chapter 2 AT-BOT Development tools Robo-Creator robot kit supports the operation controller program which can be developed from Assembly, BASIC or C programming languages. For here, we will use C/C++ programming language with the open-source software called Wiring, which is the name of a development project of a small control system in order to apply the software and hardware together.

We focus on concrete utilization as well as the connection of devices with electronic system so that the system can work according to the statement written correctly, collectively, Physical computing or the computer system which concentrates on physical signal connection, connecting external sensor devices or controlling display of LEDs, light, and sound, etc.

The official website of Wiring here is www.wiring.org.co. At this website, there is data of both hardware and software allowed to download with free of charge. Also, it is the open-source project to give an opportunity to developers who will be able to join the project and expand the project freely.

The founder of Wiring is Hernando Barragan (Architecture and Design School, Universidad de Los Andes, Comlumbia). Wiring started at the Interaction Design Institute Ivrea in Italy and it is currently developed at the Universidad de Los Andes, Architecture and Design School in Colombia.

2.1 Supported operating system The software for the program development is Wiring Development Environment or sometimes called Wiring IDE and it can work with these operating systems or platforms.  Mac OS X 10.4 or higher (both models using Powerpc and Intel CPU)  Windows XP, Windows Vista and 7  Linux, both Fedora Core and Debian (including Ubuntu as well)  Other platforms which support the operation of Java 1.4 up

2.2 Wiring hardware The main hardware of Wiring is Wiring I/O board which is a small circuit board with ATmega128 microcontroller. ATmega microcontroller is very important to control all kinds of work in which the main controller or microcontroller will be programmed

18Robo-Creator : AT-BOT activity book

through USB port in Wiring IDE software. There is a connection point to recieve signals from both analog and digital external sensors that allows the board to acquire information from the surrounding environment (temperature, light, distance to an object etc.).

Moreover, there is another point to send signals out to control external devices, such as LEDs, loudspeakers, servo motors, and liquid crystal display or LCD, etc.

Robo-Creator robot kit provides the hardware of controller board compatible with Wiring hardware and the system of Wiring IDE so you will be able to develop the program comfortably.

2.3 Introduction to Wiring 1.0 IDE Wiring 1.0 is the software for developing C/C++ programming language in order to create a program controlling ATmega1281 microcontroller on Wiring I/O hardware and then use the program in AT-BOT robot in Robo-Creator kit as well.

In the kit, tools used in development of the program are contained completely in the format of IDE (Integrated Development Environment), either the text editor for coding or C complier. Downloading the program and the window of serial monitor for receiving and sending serial information to AT-BOT robot. Wiring is designed to use easily and the C/C++ language is for programming which can work on the operating system of Windows XP up, Linux and MAC OSX and installation files for each platform are separated.

2.3.1 Software installation (1) Insert the CD Rom, come with Robo-Creator robot kit. Click the file named Wiring1000_RoboCreatorR1_Setup.exe (the number of the installation file may be changeable) and then the window of welcoming to the Wiring 1.0 setup will appear.

Robo-Creator : AT-BOT activity book ď Źď€ 19

(2) Next, click to agree in each step of the setup as installation of other applications of Windows until completion.

(3) Installing the Wiring 1.0 software by using the CD rom is bundled with RoboCreator robotic kit is the setup of both Wiring 1.0 software and USB driver to connect with ATX controller board in the same time.

(4) Test to start the program by select START > All Programs > Wiring. Then for a few moment, the window of Wiring IDE will be present.

After That you can use the Wiring IDE in the program development for AT-BOT robots.

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1

Connect with USB port

41 ADC1

40 ADC0

46 ADC6

45 ADC5

44 ADC4

5

42 ADC2

4

43 ADC3

START

4 Display RUN mode

R o b o - C r e a to r > > > > 3

> o R u n n i n g. . . o a r d 2

USB DATA

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

1

E2

KNOB

SW1

49

SERVO PORT 9

SW2

50

48

BATTERY LEVEL

10 11 12 13 S

8

+

-

Turn on power

ADC7

0

RESET

7.2-9V BATT.

2

14

PC6

15 PC7

MOTOR

3 Wait until the USB LED is on

Figure 2-1 : The steps of preparation for checking USB serial port positions of AT-BOT robot

2.3.2 Checking the USB Serial port for the AT-BOT (1) Plug the USB cable connecting ATX control board with the USB port of the computer. Turn on and wait for the blue LED at the position of USB on the circuit board is on as the figure 2-1.

(2) Click the START button and go to the Control Panel.

(3) Then double-click the System (4) Go to the tab of Hardware and click on the Device Manager button

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(5) Check the hardware listing at Port. You should see USB Serial port . Check the position. Normally it is COM3 or higher (for example; COM10). You must use this COM port with the Wiring IDE software.

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2.3.3 AT-BOT with Wiring IDE interface (1) Open Wiring IDE. Wait for a while. The main window of Wiring IDE will appear.

(2) Choose the suitable hardware by select menu Tools > Board > INEX > RoboCreator R1 > ATmega1281 @16MHz

(3) Select menu Tools > Serial Port to choose the USB serial port of AT-BOT. It is COM4 (for example).

Must do this step for every new connection of the AT-BOT with Wiring IDE

Now the AT-BOT is ready for interfacing and code development with the Wiring IDE.

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Chapter 3 Wiring IDE introduction This chapter presents preliminary information of Wiring, which is the software tool for developing the operation of AT-BOT robots or one of the activities to build robots in Robo-Creator kit. For the details of program structure of C/C++ language Wiring supports, you can read in the Wiring IDE help.

3.1 Components of Wiring IDE Wiring IDE consist of two important parts which are text editor and C/C++ compiler. There are many tool s and comm and buttons to help the program development as appeared in the figure 3-1.

3.1.1 Menu bar Including File, Edit, Sketch, Tools and Help menu, will affect work files doing at the present only.

Figure 3-1 : Main window of Wiring IDE software used in the program development

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3.1.1.1 File

New (Ctrl+N) : Create new files. This is called sketch in Wiring and given name following the recent date in the format sketch_YYMMDDa, such as sketch_080407a or click the button

on the tool bar.

Open (Ctrl+O) : Open the exist sketch file or click on the button

.

Close (Ctrl+W) : Choose to close the sketch file.

Save (Ctrl+S) : Save the open sketch file in the old name and work similarly to click the button

on the tool bar.

Save as…(Ctrl+Shift+O) : Save the open sketch file in the new name and the old file will not disappear.

Upload to Wiring hardware (Ctrl+U) : Exports the program to the Wiring I/O Board (inthis document is the ATX controller board). After the files are exported, the directory containing the exported files is opened. There is more information about uploading below. It works in the same way as click the button on

the tool bar.

Preference : Customize the operation of Wiring IDE Quit (Ctrl+Q) : Quit the Wiring program and close all windows of Wiring program.

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3.1.1.2 Edit The menu contains commands used to edit the sketch file that develops on the Wiring IDE.

Undo (Ctrl+Z) : cancel the previous action of a command or the lastest typing.

You can cancel Undo command by click Edit > Redo.

Redo (Ctrl+Y) : To return to make a statement made before the Undo command is available only when done Undo already.

Cut (Ctrl+X) : Delete and copy the selected text to store at the clipboard, which functions as the temporary memory unit to preserve information.

Paste (Ctrl+V) : Place the data in the clipboard on the desired position or replace the selected text.

Select All (Ctrl+A) : Select all letters or text in the open file in the text editor at that time.

Find (Ctrl+F) : Search for any text in the open file in the text editor. In addition, it is also able to find and replace another text.

Find Next (Ctrl+G) : Find text or words we use to search for the next one within the open file in the text editor.

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3.1.1.3 Sketch Sketch menu is a command menu relating to compile a sketch file.

Verify/Compile (Ctrl+R) : It is a command of program compilation and its function is similar to pressing the

button on the tool bar.

Import Library : Open the included library of Wiring.

Show Sketch Folder : Show the folder of the current sketch file.

Add File: Add the required program file to the sketch file.

3.1.1.4 Tools Tools menu is a command menu relating to selection of tools helped to develop a program. Important commands you should know are as follows.

Auto Format : Try to format program code in the completed form.

Serial Monitor : Open the serial data terminal.

Board : Choose the interfaced hardwarere with the Wiring 1.0.

Serial Port : Choose the interfaced port of the Wiring I/O hardware.

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3.1.1.5 Help

Getting Started : Open the window about the using Wiring of the Wiring website.

Examples : Open a sketch file of an example program.

Reference : Open Reference window of the Wiring website. It consists of language, programming environment, libraries, and language comparison. You have to connect with the internet if you would like to see the information.

Find in Reference (Ctrl+Shift+F) : Choose text in your program code. Here you will drag black bar and click on it. The program will take the text you have chosen to find in reference and if it cannot find anything, there will be a warning message in the window of the program.

Wiring Hardware : Browse the information of Wiring I/O hardware via internet.

Troubleshooting : Open the window about solutions in performance of the Wiring of the Wiring website.

Visit wiring.org.co (Ctrl+5) : Open the web browser to visit the homepage of Wiring at http://wiring.org.co.

About Wiring : Show the copyright on the Wiring software

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3.1.2 Toolbar There are six buttons of basic functions and initial operation as follows.

Run or Compile : This button is used to compile the program code.

New : This button is used to create a sketch file.

Open : Open the exist sketch file Save : Save the open sketch file in the old name. If would like to change filename, use Save As command instead.

Upload to Wiring hardware : Exports the program to the ATX controller board). This procedure is called UPLOAD. Serial monitor : opens the serial data communication between the Wiring I/O hardware and the monitor of Wiring IDE through serial ports (or COM port) to check the information sent back from Wiring I/O hardware (here it is ATX control board, which is very useful for the detection of the program’s operation).

3.1.3 Serial monitor Wiring IDE has a Serial monitor. It is a serial data communication tool. User can transmit, receive and show the serial data via this monitor with USB serial port of computer.

In the developed sketch code, must put two imporatant commnands as follows : 1. Serial.begin() : Set the baud rate of serial data communication. Normally the baud rate value is 9600 bit per second. Must add this command into Setup() of sketchbook.

2. Serial.println() : Assign the sending message to Serial monitor on the Wiring IDE. Openning the Serial monitor is very easy. Click on the Serial monitor window is appeared following the figure below.

button at Toolbar. The

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3.2 How to develop the program (1) Check the installation of the hardware and software of Wiring. Include the setting USB serial port that connected with Wiring I/O hardware; the ATX control board of AT-BOT robot in Robo-Creator kit.

(2) Create a new sketch file by a click of the New button on the Tools bar or choose from menu File > New

(3) Type the example code as as follows : #include <atx.h> int ledPin = 48; void setup() { lcd("Hello Robot!"); pinMode(ledPin, OUTPUT); } void loop() { digitalWrite(ledPin, HIGH); delay(1000); digitalWrite(ledPin, LOW); delay(1000); }

// Include main library // LED connected to pin 48 (bootloader)

// Title message on LCD // Sets the digital pin as output

// Sets the LED on // Waits for a second // LED off

This program is used to test a basic hardware of AT-BOT robot. At the LCD display shows message Hell Robot ! and blink the LED at port 48 of the ATX controller board with one second rate.

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(4) Go to the File menu to choose the Save as command to save the file in the name of Test. Now, there is test.pde file happening in the folder called test.

(5) Verify the sketch by click onthe Run button of choose from menu Sketch > Compile/Verify

If there is any error occurring from compilation, a warning message will be appeared in the messsage area. Therefore, you will have to correct the program.

If all are correct, the message area will display Done compiling message.

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1 Connect to USB port 5 Display the programming mode

41 ADC1

40 ADC0

46 ADC6

45 ADC5

44 ADC4

5

42 ADC2

4

43 ADC3

START

4

R o b o - C r e a to r > > > > 3

> o B o o t l o ad e r o a r d

Press and hold the START button 3 seconds.

The robot enter to programming mode

2

USB DATA

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

1

E2

SW1

49

SERVO PORT 8

9

SW2

50

48

LED at port 48 is on for programming mode

BATTERY LEVEL

10 11 12 13 +

-

7.2-9V BATT.

Turn-on power

ADC7

0

KNOB

RESET

S

2

14

PC6

15

PC7

MOTOR

3 The blue LED of USB ready is on

Figure 3-2 : Illustration of AT-BOT robot controlled to enter the program mode After the compilation is finished, in the folder of test there will be a new folder are in named Build and within this folder it contains the source file of C++ programming language and a supplementary file.

(6) Connect the ATX board with USB port. Turn-on power. Wait until USB connection is completely ( blue LED at USB is turned-on) .

(7) Press and hold the START button on the ATX controller board 3 seconds. The LCD module shows Entry program mode message following the figure 3-2.

(8) Click on the

Upload to Wiring Hardware. Code uploading is started. Wait

until uploading complete. The message Done uploading. RESET to start the new program. is shown in the status bar of Wiring IDE.

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If there is error occurring from uploading, a warning message will be appeared in the messsage area as follows

This mostly occurs if the serial port is invalid or not selected the board to work in the program mode. Correction can be read in the topic of Troubleshooting of uploading error.

(9) Press on the START button on the ATX control board to start the operation of the program.

At the display of ATX board; it shows message Hello Robot! and the LED at the port 48 lights up.

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3.3 Troubleshooting of uploading error.

3.3.1 In case that you have clicked the Upload button already but no any action Cause : Wiring software cannot link with ATX control board of AT-BOT robot because it is not in the program mode.

Solution : (1) Press the Ctrl, Alt and Delete key simultaneously and then the Window Security window will pop up. Next, click on Task Manager to choose. In some computers, the program may lead to the Window Task manager window immediately, in this case, you can choose the Processes tab and search for the file named avrdude.exe. Finally, click on that file and the End Process button respectively.

(2) Wiring IDE program will resume in a normal status and supply power to the board again. Select the correct COM port and then set the ATX board to the programming mode in order to upload the program again.

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3.3.2 In case if you click the Upload button, there is an error message that not find any hardware for uploading

Cause : Wiring software cannot connect with ATX control board or AT-BOT robot because selecting a COM port is not correct.

Solution : You need to choose an another COM port used for the connection again and correctly by doing at the Tools > Serial port.

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Chapter 4 ATX Library file Developing C/C++ programming language with Wiring for AT-BOT robots is managed under the support of atx.h library file in order to reduce steps and complexity in programming to control parts of the hardware because it is required to give the priority for the program development controlling AT-BOT robots to programming to support competitions.

The structure of atx.h library file shown as the diagram and details of all sub files are consisted of as follows.

atx.h library file

                

                   

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4.1 lcd.h library file of LCD module displaying This library file supports the instruction set about the display of messages at the LCD module. Before activating the function of this library, you should append the library file in the first part of the program with the statement. #include <lcd.h> or #include <atx.h> The main function of this library is lcd., which contains the function for message display at the LCD module in the type of 16 characters and 2 lines.

Syntax

void lcd(char *p,...)

Parameter p - Type of display data. Support the special character for setting display method.

Command

Operation

%c or %C

Display 1 character

%d or %D

Display the decimal value -32,768 to +32,767

%l or %L

Display the decimal value -2,147,483,648 to +2,147,483,647

%f or %F

Display floating point 3 digits

#c

Clear message before next display

#n

Display message on the second line (bottom line)

Example 4-1 lcd(“Hello LCD”);

// Displays Hello LCD message at LCD module

Result :

H e l l o o L C D rb o a r d r W i r i n g I / Ob R o b o t d

Example 4-2 lcd(“abcdefghijklmnopqrstuvwxyz”); // Display string. If over 16 charactes, the next character will // show on the second line automatically.

Result :

abcdefghijklmnop q r s t u v w x yz R o b o t d

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Example 4-3 lcd(“Value: %d unit “,518); // Display message with number date (518) Result :

Value:g518kunitp q r s t u v w x yz R o b o t d

Example 4-4 lcd(“Value: %d “,analog(4)); // Display analog value from analog port 4 (PA4) Result :

Value:gxxxkunitp q r s t u v w x yz R o b o t d

therefore xxx as reading value 0 to 1023

Example 4-5 char c_test=’j’; lcd(“abcd%cxyz”,c_test); // Display character j with any message Result :

abcdjxyzxxkunitp q r s t u v w x yz R o b o t d

Example 4-6 lcd(“Value: %f “,125.450); // Display message with floating number 3 digit Result :

Value:g125.450tp q r s t u v w x yz R o b o t d

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Example 4-7 lcd(“count1: %d #ncount2: %d”,12,48); // Display message with 2 control code and special key #n // for moving all message after #n to line 2 or bottom line of // LCD screen Result

count1:112.450tp c o u n t 2 : x 48 R o b o t d

4.2 sleep.h : The delay time library This library file supports all instructions for time delaying. This library must be included at the top of the program with the command #include as follows : #include <sleep.h> or #include <atx.h> The important function is sleep . It delay time in millisecond unit.

Syntax

void sleep(unsigned int ms) Parameter ms - Set the delay time in millsecond unit. Range is 0 to 65,535.

Example 4-8 sleep(20); sleep(1000);

// Dealy 20 miliisecond // Delay 1 second

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4.3 in_out.h : Digital input/output port library This library file supports all instructions for readind and writing data to digital port of controller board. This library must be included at the top of the program with the command #include as follows : #include <in_out.h> or #include <atx.h> Important functions of this library file are consisted of :

4.3.1 in Read data from the specific digital port Syntax

char in(x) Parameter x - Choose digital port number. it is 0 to 50 Return value 0 or 1

Example 4-9 char x;

// Declare x variable for keeping reading input data

x = in(49);

// Read port 49 and store data to x variable.

Example 4-10 char x;

// Declare x variable for keeping reading input data

x = in(50);

// Read port 50 and store data to x variable.

4.3.2 out Write or send the data to the specific digital port Syntax

out(char _bit,char _dat) Parameter _bit - Choose digital port number. it is 0 to 50

Example 4-11 out(43,1);

// Write port 43 with logic “1”

out(45,0);

// Write port 45 with logic “0”

4.3.3 sw1_press This function loops to check the SW1 pressing. It returns value after switch is released.

Syntax

void sw1_press() Example 4-12 ................ sw1_press(); ................

// Wait until the SW1 is pressed and released

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4.3.4 sw2_press This function loops to check the SW2 pressing. It returns value after switch is released.

Syntax

void

sw2_press()

Example 4-13 ..................

Sw2_press(); // Wait until the SW2 is pressed and released .................

4.3.5 sw1 This function check the SW1 pressing in any time.

Syntax

char

sw1()

Return value “0” - SW1 is pressed “1” - SW1 is not pressed

Example 4-14 char x;

// Declare x variable for keeping the value

x = sw1();

// Get SW1 status and store to x variable

4.3.6 sw2 This function check the SW2 pressing in any time.

Syntax

char

sw2()

Return value “0” - SW2 is pressed “1” - SW2 is not pressed

Example 4-15 char x;

// Declare x variable for keeping the value

x = sw2();

// Get SW2 status and store to x variable

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4.4 analog.h : Analog port library This library file supports all instructions for reading the analog input port of the ATX controller board. This library must be included at the top of the program with the command #include as follows : #include <analog.h> or #include <atx.h>

4.4.1 analog This gets digital data from the analog to digital converter module of any analog port; ADC0 to ADC7.

Syntax

unsigned int analog(unsigned char channel) Parameter channel - Analog input (ADC0 to ADC7) Return value Digital data from analog to digital converter module. The value is 0 to 1023 (in decimal)

4.4.2 knob This function gets data from ADC7 port. This port isconnected with variable resistor on-board. It is called KNOB. Syntax

unsigned int knob() Return value Digital data from analog to digital converter module. The value is 0 to 1023 (in decimal)

Example 4-16 int val=0;

// Declare variable to keep the converted data

val

// Get data from analog input ch. 2 (ADC2) // and store data to val variable.

= analog(2);

Example 4-17 int val=0;

// Declare variable to keep the converted data

val

// Get data from analog input ch. 7 // (ADC7 or KNOB) and store data to val // variable

= knob();

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4.5 motor.h : DC motor driving library This library file supports all instructions for driving and controlling 6 DC motor outputs of the ATX controller board. This library must be included at the top of the program with the command #include as follows : #include <motor.h> or #include <atx.h>

4.5.1 motor It is DC motor driving function.

Syntax

void motor(char _channel,int _power) Parameter _channel - DC motor output of ATX board; value is 0 to 5 _power - Power output value; it is -100 to 100 If set _power as positive value (1 to 100); motor is driven one direction.

If set _power as negative value (-1 to -100); motor is driven opposite direction.

If _power as 0; motor is stop. This value is not recommended. Use motor_stop function to stop motor better.

Example 4-18 motor(1,60);

// Drive motor ch.1with 60% of maximum power

motor(1,-60);

// Drive motor ch.1with 60% of maximum power and turn back

direction.

Example 4-19 motor(2,100);

// Drive motor ch.2 with maximum power

4.5.2 motor_stop This function is driving off a motor or stop.

Syntax

void motor_stop(char _channel) Parameter _channel - DC motor output of ATX board; value is 0 to 5 and all (for driving off all channels)

Example 4-20 motor_stop(1);

// Stop motor ch.1

motor_stop(4);

// Stop motor ch.4

Example 4-21 motor_stop(ALL);

// All motor are stop

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4.6 servo.h : Servo motor library This library file supports all functions for controlling 6 servo motor outputs of the ATX controller board. This library must be included at the top of the program with the command #include as follows : #include <servo.h> or #inclue <atx.h> There is one function. It is servo.

Syntax void servo(unsigned char _ch, int _pos)

Parameter _ch - Servo motor output (8 to 13) _pos - Set the sevo motor shaft poistion (0 to 180 and -1) If set to -1, disable selected servo motor output

4.7 sound.h : Sound generating library This library file supports all functions for sound generating of the ATX controller board and AT-BOT. This library must be included at the top of the program with the command #include as follows : #include <sound.h> or #inclue <atx.h>

4.7.1 beep It is beep sound generating function. The beep frequency is 500Hz and 100 millisecond duration time.

Syntax

void beep()

4.7.2 sound This is programmable sound generating function.

Syntax

void sound(int freq,int time) Parameter freq - Set frequency with value 0 to 32,767 time - Set duration time in millisecond unit from 0 to 32,767

Example 4-22 beep();

// Drives beep sound with 100 millisecond duration

sound(1200,500);

// Drives sound with 1200Hz 500 millisecond

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4.8 serial.h : Serial data communication library This library file supports all functions for sending and receiving the serial data via UART port of the ATX controller board and AT-BOT. This library must be included at the top of the program with the command #include as follows : #include <serial.h> or #include <atx.h>

4.8.1 Hardware connection UART0 port UART0 port is connected via USB to Serial converter chip; FT232RL. For connecting with computer, must connect via USB port on the ATX controller board. This connector is same port for downloading.

UART1 port Connect via RXD1 (port 2 ) and TXD1 (port 3)

4.8.2 uart This is serial data sending function via UART0 port. The default baudrate is 115,200 bit per second.

Syntax

void uart(char *p,...)

Parameter p - Type of data. Support the special character for setting display method.

Command

Operation

%c or %C

Display 1 character

%d or %D

Display the decimal value -32,768 to +32,767

%l or %L

Display the decimal value -2,147,483,648 to +2,147,483,647

%f or %F

Display floating point 3 digits

\r

Set the message left justify of the line

\n

Display message on the new line

4.8.3 uart_set_baud This is baud rate setting function for UART0.

Syntax

void uart_set_baud(unsigned int baud) Parameter baud - Baud rate of UART0 2400 to 115,200

Example 4-23 uart_set_baud(4800);

// Set baud rate as 4,800 bit per second

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4.8.3 uart_available This is receiveing data testing function of UART0.

Syntax

unsigned char uart_available(void) Return value - “0” : no data received - more than 0 : received character

Example 4-24 char x =uart_available(); // Check the recieving data of UART0. // If x value is more than 0; it means UART0 get any data. // Read it by using uart_getkey function in the order next immediately.

4.8.4 uart_getkey This is data reading function from receiver’s buffer of UART0 Syntax

char uart_getkey(void) Return value - “0” : no data received - data : received character in ASCII code

Example 4-25 #include <robot.h> // Get function void setup() { } void loop() // Main loop { if(uart_available()) // Check incoming data { if(uart_getkey()==’a’) // Is key ‘a’ pressed ? { lcd(“Key a Active!”); // Display message when get ‘a’ sleep(1000); // Delay 1 second } else { lcd(“#c”); // Clead display } } } Note : Default baud ratre of UART library is 115,200 bit per second. Data format is 8-bit and no parity.

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4.8.5 uart1 This is serial data sending function via UART1 port. The default baud rate is 9,600 bit per second.

Syntax

void uart1(char *p,...)

Parameter p - Type of data. Support the special character for setting display method. See details in uart0 function.

4.8.6 uart1_set_baud This is baud rate setting function for UART1.

Syntax

void uart1_set_baud(unsigned int baud) Parameter baud - Baud rate of UART0 2400 to 115,200

Example 4-26 uart1_set_baud(19200); // Set baud rate as 19,200 bit per second

4.8.7 uart1_available This is receiving data testing function of UART0.

Syntax

unsigned char uart1_available(void) Return value - “0” : no data received - more than 0 : received character

Example 4-27 char x =uart1_available();

// Check the receiving data of UART1.

4.8.8 uart1_getkey This is data reading function from receiver’s buffer of UART1.

Syntax

char uart1_getkey(void) Return value - “0” : no data received - data : received character in ASCII code

Robo-Creator : AT-BOT activity book ď Źď&#x20AC; 47

4.9 Digital compass library It is compass.h file. This library file is not included in robot.h library file. Must include the specific library file before using.

This library file supports all functions for interfacing the HMC6352 digital compass of the ATX controller board. This library must be included at the top of the program with the command #include as follows : #include <compass.h>

4.9.1 compass_read This reads the angle of the HMC6352 digital compass.

Syntax

int compass_read() Return value Angle value 0 to 359 defree

4.9.2 compass_set_heading This is reference angle setting function. With this function, the current angle that read from digital compass is set to 0 degree reference.

Syntax

void compass_set_heading()

4.9.3 compass_read_heading This is reference angle reading function. Use this function after set the new reference angle from compass_set_heading function.

Syntax

int compass_read_heading() Return value 1 to 180 : positive angle (clock wise direction) of digital compass.

-1 to -180 : negative angle (Counter-Clockwise direction) of digital compass.

48 Robo-Creator : AT-BOT activity book

Robo-Creator : AT-BOT activity book ď Źď&#x20AC; 49

Chapter 5 The ATX controller board hardware experiment This chapter presents examples of the hardware experiment with the ATX controller board of the Robo-Creator robotic kit. There are 7 experiments as follows.

Experiment 1 Shows message on the display of the ATX board Experiment 2 Using SW1 and SW2 switch Experiment 3 Reading analog from KNOB button of the ATX board Experiment 4 Sound activity Experiment 5 DC motors control Experiment 6 Servo motor control Experiment 7 Serial data communication with computers

50 Robo-Creator : AT-BOT activity book

Programming and Hardware experiment steps (1) Open Wiring IDE and create a new sketch file.

(2) Type the code on the test editor of the sketch file (3) Compile by click at the

button or choose at the menu Compile > Verify.

(4) Connect the ATX controller board with a USB port. Turn on power and wait until the connection between the computer and ATX board is completed. This can be noticed from the blue LED at the position of USB power on.

(5) Set the ATX board to program mode by pressing START switch and hold it for 3 seconds.

At the ATX board display, it shows messages

Robo-Creator > Bootloader and the red LED at the port 48 is powered on.

(6) Upload the code by click at the Wiring hardware.

button or click at the menu file > Upload to

(7) Wait until the uploading is successful. Then press the START switch again. Finally, the ATX controller circuit board will be running the latest uploaded program immediately.

Program L1-1

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Experiment 1 Shows message on the display of the ATX board Experiment 1.1 Simple message displaying on the ATX board This experiment demonstrates the simle programming for showing the message at the display of the ATX board.

Procedure L1.1.1 Create the new sketch file. Type the Listing L1-1 and save as lcd_01.pde file L1.1.2 Compile and upload the sketch to the ATX board.

L1.1.3 Run the program.

41 ADC1

40 ADC0

46 ADC6

45 ADC5

44 ADC4

5

42 ADC2

4

43 ADC3

START

At the LCD display of the ATX controller board show message Hello Robot! as follows.

Hel lo C Rob ot! > > > > 3

> o B o o t l o ad e r o a r d 2

USB DATA

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

1

E2

KNOB

ADC7

SW1

49

SW2

50

48

SERVO PORT 9

BATTERY LEVEL

10 11 12 13 S

8

+

-

7.2-9V BATT.

0

RESET

14

PC6

15 PC7

MOTOR

#include <atx.h> // Include the main library void setup() { lcd("Hello Robot!"); // Display mesage on the ATX display } void loop() {}

Code explanation This code runs within the setup function. There is one command. Display the message; Hello Robot! on the screen. After that the program will jump to run in the loop function. No any command in this function. The operation is stop finally.

Listring L1-1 : lcd_01.pde, the sketch file for simple displaying message on the ATX board.

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Experiment 1.2 Display message 2 lines of the ATX board display This experiment demonstrates the displaying message 2 lines of the ATX board display.

Procedure L1.2.1 Create the new sketch file. Type the Listing L1-2 and save as lcd_02.pde file L1.2.2 Compile and upload the sketch to the ATX board.

L1.2.3 Run the program.

41 ADC1

40 ADC0

46 ADC6

45 ADC5

44 ADC4

5

42 ADC2

4

43 ADC3

START

At the LCD display of the ATX controller board show message as follows :

3

Lin e1 C Rob ot! > > > > Lin e2 t l o a d e r o a r d

2

USB DATA

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

1

E2

KNOB

ADC7

SW1

49

SW2

50

48

SERVO PORT 9

10 11 12 13 S

8

BATTERY LEVEL +

-

7.2-9V BATT.

0

RESET

#include <atx.h> void setup() {} void loop() { lcd(“Line1#nLine2”); }

14

PC6

15 PC7

MOTOR

// Include the amin library

// Display message 2 lines

Code explanation The program starts running in the setup function then it repeats working in the loop function to display message on both lines of the LCD. The result comes from the operation of control code #n. The overall results have been shown the display of 2-line text.

Listring L1-2 : lcd_02.pde, the sketch file for displaying message 2 lines on the ATX board display.

Robo-Creator : AT-BOT activity book  53

Experiment 1.3 Shows message and number This experiment demonstrates showing messages mixed with numbers at the ATX board display. It shows the values of counting in every 1 second.

Procedure L1.3.1 Create the new sketch file. Type the Listing L1-3 and save as lcd_03.pde file L1.3.2 Compile and upload the sketch to the ATX board.

L1.3.3 Run the program.

At the LCD display of the ATX controller board show message as follows :

Count: xxx

41 ADC1

40 ADC0

46 ADC6

45 ADC5

44 ADC4

5

42 ADC2

4

43 ADC3

START

therefore xxx is counting value that increse every second.

3

Cou nt:R20 0t! > > > > Lin e2 t l o a d e r o a r d

2

USB DATA

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

1

E2

KNOB

ADC7

SW1

49

SW2

50

48

SERVO PORT 9

10 11 12 13 S

8

BATTERY LEVEL +

-

7.2-9V BATT.

0

RESET

14

PC6

15 PC7

MOTOR

#include <atx.h> // Include the main library int i = 0; // Declare the counting variable void setup() {} void loop() { lcd("Count: %d ",i); // Display the counter on the ATX board display sleep(1000); // Delay 1 second i++; // Increase counter }

Code explanation The program starts running in the setup function and then it repeats working in the loop function. It shows the counting value that increased every 1 second. The variable i stores the count values.

Listring L1-3 : lcd_03.pde, the sketch file for displaying message and number on the ATX board.

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Experiment 2 Using SW1 and SW2 switch Experiment 2.1 Using SW1 to start the counter This expeirment demonstrates how to use the SW1 on the ATX controller board to start the counter. The counting values also should be display on the ATX board display.

Procedure L2.1.1 Create the new sketch file. Type the Listing L2-1 and save as switch_01.pde file L2.12 Compile and upload the sketch to the ATX board.

#include <atx.h> int i=0; void setup() { lcd("SW1 Press!"); sw1_press(); lcd("#c"); } void loop() { lcd("Count: %d ",i); sleep(1000); i++; }

// Include the main library // Declare the counter variable

// Display the title message // Wait the SW1 pressing // Clear display before show the next message

// Display the counting value // Delay 1 second // Increase counter

Code description The program starts running in the setup function to wait for the pressing of SW1 and there is an alert by the text of SW1 Press! at the display after the switch is pressed. The program will repeat working in the loop function to display the count value that is increased in every 1 second. The i variable is used to stores the count values.

Listing L2-1 : switch_01.pde, the sketch file for checking the SW1 of the ATX board pressing to start the counter

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L2.1.3 Run the program.

At the LCD display of the ATX controller board show message as follows :

SW1 Press!

L2.1.4 Press the SW1 on the ATX board and release.

Counting is start. The counter value is displayed on the ATX board display as follows.

Count: xxx

41 ADC1

40 ADC0

46 ADC6

45 ADC5

44 ADC4

5

42 ADC2

4

43 ADC3

START

therefore xxx is counting value that increase every second.

3

Cou nt:R20 0t! > > > > Lin e2 t l o a d e r o a r d

2

USB DATA

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

1

E2

KNOB

ADC7

SW1

49

SW2

50

48

SERVO PORT 9

Press the switch SW1 to start

BATTERY LEVEL

10 11 12 13 S

8

+

-

7.2-9V BATT.

0

RES ET

14 PC6

15 PC7

MOTOR

Experiment 2.2 Checking the SW1 and SW2 pressing anytime This experiment demonstrates the checking of SW1 and SW2 of the ATX board pressing. It used to increase and decrease the variable value. Also display the value on the LCD module of ATX board.

Procedure L2.2.1 Create the new sketch file. Type the Listing L2-2 and save as switch_02.pde file L2.2.2 Compile and upload the sketch to the ATX board.

L2.2.3 Run the program.

At the LCD display of the ATX controller board show message as follows :

Count: xxx therefore xxx is the counting value. Start from 10.

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#include <atx.h> int i=10;

// Include the main library // Declare the counter variable // and set to start from 10

void setup() {} void loop() { lcd("Count: %d ",i); // Display the counting value if(sw1()==0) // SW1 is pressed ? { i++; // If SW1 is pressed, increase counter. sleep(200); // Delay for switch debouncing } if(sw2()==0) // SW2 is pressed ? { i-- ; // If SW2 is pressed, decrease counter sleep(200); // Delay for switch debouncing } } Code description The program begins operating in the setup function. Then it repeats in the loop function.

It loop to check up pressing the switch of SW1 and SW2 all the time and display the count values of the variable I at the LCD module as well.

Conditions of verification in the loop as following these: 1. If the SW1 is pressed ( sw1 ( ) function returns the value as 0) The program responds by increase value of the variable i 2. If the SW2 is pressed (sw2 ( ) function returns the value as 0 ) The program responds by decrease value of the variable i.

Listing L2-2 : switch_02.pde, the sketch file for checking both SW1 and SW2 of the ATX board pressing anytime

Robo-Creator : AT-BOT activity book  57

L2.2.4 Press the SW1 switch on the ATX board. Observe the operation of the ATX board display.

Each time you press the SW1, the count value is added up one value L2.2.5 Press the SW2 switch on the ATX board. Observe the operation of the ATX board display.

41 ADC1

40 ADC0

46 ADC6

45 ADC5

44 ADC4

5

42 ADC2

4

43 ADC3

START

Each time you press the SW2, the count value is deduct one value.

3

Count:R20 0t! > > > > Line2 t l o a d e r o a r d

2

USB DATA

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

1

E2

KNOB

ADC7

SW1

49

SW2

50

48

SERVO PORT 9

BATTERY LEVEL

10 11 12 13 S

8

+

-

7.2-9V BATT.

0

RES ET

14

PC6

15 PC7

MOTOR

Press SW1 to increase value

Press SW2 to decrease value

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Experiment 3 Reading analog from KNOB button of the ATX board Experiment 3.1 Knob value reading This experiment demonstrates how to read the analog value from KNOB button of the ATX controller board. It is basic example of analog sensor reading. The result is 0 to 1023.

Procedure L3.1.1 Create the new sketch file. Type the Listing L3-1 and save as knob_01.pde file L3.1.2 Compile and upload the sketch to the ATX board.

L3.1.3 Run the program.

At the LCD display of the ATX controller board show message as follows :

KNOB: xxx therefore xxx as KNOB position value from 0 to 1023 - Adjust to last left position. Value is 0.

- Adjust to last right position. Value is 1023.

41 ADC1

40 ADC0

46 ADC6

45 ADC5

44 ADC4

5

42 ADC2

4

43 ADC3

START

- Adjust to center position. Value is 512.

3

KNO B::101 0t! > > > > Lin e2 t l o a d e r o a r d

2

USB DATA

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

1

E2

KNOB

ADC7

SW1

49

SW2

50

48

SERVO PORT 9

BATTERY LEVEL

10 11 12 13 S

8

+

-

7.2-9V BATT.

0

RES ET

14

PC6

15 PC7

MOTOR

Adjust the KNOB shaft to reading

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#include <atx.h> void setup() {} void loop() { lcd("KNOB: %d sleep(100); }

// Include the main library

",knob());

// Display the KNOB value // Delay 0.1 second for displaying

Code explanation The program begins operating in the setup function. Then it repeats in the loop function to display the readable values from KNOB at the LCD module.

Knob value is read by using knob function of the atx.h library. It is analog to digital converter function.

Listing L3-1 : knob_01.pde, the sketch file for reading the KNOB button of the ATX board value.

Experiment 3.2 Use KNOB button to Mode selector This experiment demonstrates about programming to use KNOB as the directional determinant of counting value. If KNOB is adjusted to the left to compare with the middle position, this will be the selection to count down values but if it is opposite, it will be the selection to count values up. Additionally, the display of the count value is shown at the LCD module.

Procedure L3.2.1 Create the new sketch file. Type the Listing L3-2 and save as knob_02.pde file L3.2.2 Compile and upload the sketch to the ATX board.

L3.2.3 Run the program.

At the LCD display of the ATX controller board show message as follows :

Count: xxx Count Up in the Count up mode or

Count: xxx Count Down in the Count down mode therefore xxx is thge counting value. Start from 100.

60 Robo-Creator : AT-BOT activity book

#include <atx.h> int i=100; int k; void setup() {} void loop() { lcd("Count: %d k = knob(); if(k>512)

// Include the main library // Declare the counter variable. Start from 100 // Declare the KNOB value variable

",i);

// // // //

Display counter Read the KNOB value to store to the k variable Check the KNOB’s value is through the middle to right or not ?

{ i++; lcd("#nCount Up

");

} else { i--; lcd("#nCount Down } sleep(1000);

");

// Increase the count value // Display the Count up mode message // on the lower line of LCD

// // // //

If the KNOB’s value is through the middle to left, count down Display the Count down mode message on the lower line of LCD

// Delay 1 second

}

Code explanation The program begins operating in the setup function. Then it repeats in the loop function to verification of adjustment position of KNOB continually. At the same time, the count value of the variable i and the counting mode at the LCD module as well. There are conditions for the verification as follows: 1. If the KNOB value is greater than 512 The program will respond to adding up the count value of the variable i to one value and show the Count up mode message on the display.

2. If the KNOB value is less than 512 (working in the section of else).

The program will respond to deducting the count values of the variable i to one value and show the Count down mode message on the display.

Listing L3-2 : knob_02.pde, the sketch file for using the KNOB button of the ATX board to Mode selector

Robo-Creator : AT-BOT activity book  61

41 ADC1

40 ADC0

46 ADC6

45 ADC5

44 ADC4

5

42 ADC2

4

43 ADC3

START

The program wil count up and down depending on the value of KNOB, which is result from the rotation of spindle of the variable resistor at the position of KNOB of ATX board.

3

Count:120 0t! > > > > Count t Up a d e r o a r d

2

USB DATA

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

1

E2

KNOB

ADC7

SW1

49

SW2

50

48

SERVO PORT 9

10 11 12 13 S

8

BATTERY LEVEL +

-

7.2-9V BATT.

0

RES ET

14

PC6

15 PC7

MOTOR

Adjust the KNOB shaft to change the counting mode  Left direction to count down mode  Right direction to count up mode

L3.2.4 Adjust the KNOB shaft to go through the middle to the left (or may adjust to the left) This will be found that the counter is in Count down mode. The count value will be deducted 1 value in each second.

L 3.2.5 Adjust the KNOB shaft to go through the middle to the right (or maybe adjust to the far right) The counter is in Count up mode. The count value will be added up 1 value in each second.

62 Robo-Creator : AT-BOT activity book

Experiment 4 Sound activity Exeperiment 4.1 The signal selector This experiment demonstrates about using the SW1 and SW2 on the ATX controller board to generate the different sound frequency. If SW1 is pressed, ATX board drives 500Hz signal with 0.1 second duration. If the SW2 is pressed, it generate 2000Hz (2kHz) signal with 0.5 second instead.

Procedure L4.1.1 Create the new sketch file. Type the Listing L4-1 and save as sound_01.pde file L4.1.2 Compile and upload the sketch to the ATX board.

L4.1.3 Run the program. Press the SW1 on the ATX controller board.

Everytime to press the switch SW1, you will hear the sound with the frequency of 500 Hz for 0.1 second from the piezo speaker on the ATX board.

L 4.1.4 Press the switch SW2

41 ADC1

40 ADC0

46 ADC6

45 ADC5

44 ADC4

5

42 ADC2

4

43 ADC3

START

Everytime to press the SW2, you will hear the sound of frequency 2000Hz for 0.5 second.

3

Cou nt:R20 0t! > > > > Lin e2 t l o a d e r o a r d

2

USB DATA

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

1

E2

KNOB

ADC7

SW1

49

SW2

50

48

SERVO PORT 9

BATTERY LEVEL

10 11 12 13 S

8

+

-

7.2-9V BATT.

0

RES ET

14 PC6

15 PC7

MOTOR

Press SW1 to generate 500Hz signal

Press SW2 to generate 2000Hz signal

Robo-Creator : AT-BOT activity book ď Źď&#x20AC; 63

#include <atx.h> void setup() { } void loop() { if(sw1()==0) { beep(); sleep(100); } if(sw2()==0) { sound(2000,500); sleep(100);

// Include the main library

// The SW1 is pressed ? // If SW1 is pressed, // generate the 500Hz signal 0.1 second duration // Delay for switch debouncing // The SW2 is pressed ? // If SW2 is pressed, // generate the 2000Hz signal 0.5 second duration // Delay for switch debouncing

} }

Code explanation The program operates in the loop function to check the pressing of the SW1 and SW2 switches and there are conditions as follows.

1. If the SW1 is pressed (sw1( ) function returns the value as 0) The program will respond to generate the 500Hz signal for 0.1 second.

1. If the SW2 is pressed (sw2( ) function returns the value as 0) The program will respond to generate the 2000Hz signal for 0.5 second.

Listing L4-1 : sound_01.pde, the sketch file for using the SW1 and SW2 on the ATX board to set the condition for signal generating

64 Robo-Creator : AT-BOT activity book

Experiment 4.2 Tuning frequency by KNOB This experiment demonstrates about using KNOB button to adjust the sound frequency and show the frequency value at the ATX board display

Procedure L4.2.1 Create the new sketch file. Type the Listing L4-2 and save as sound_02.pde file L4.2.2 Compile and upload the sketch to the ATX board.

L4.2.3 Run the program.

At the LCD display of the ATX controller board show message as follows :

Freq: xxx Hz therefore xxx is the generated signal frequency L4.2.4 Asjust the KNOB button slowly from left to right direction. See the display operation and listen the sound signal from ATX board.

41 ADC1

40 ADC0

46 ADC6

45 ADC5

44 ADC4

5

42 ADC2

4

43 ADC3

START

The frequency of the sound displaying at the LCD module will increase from 0 to 2046Hz (as 2 times of the value read from KNOB). The sound you have listen will be dramatically sharpened following the adjustment of frequency increasing.

3

Freq::120 0tHz > > > Line2 t l o a d e r o a r d

2

USB DATA

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

1

E2

KNOB

ADC7

SW1

49

SW2

50

48

SERVO PORT 9

BATTERY LEVEL

10 11 12 13 S

8

+

-

7.2-9V BATT.

0

RES ET

14

PC6

15 PC7

MOTOR

Adjust the KNOB button to change the sound frequency

Robo-Creator : AT-BOT activity book ď Źď&#x20AC; 65

#include <atx.h>

// Include the main library

int k;

// Declare the KNOB value variable

int f;

// Declare the frequency variable

void setup() { } void loop() { k = knob();

// Read the KNOB value to store in the k variable

f = 2*k;

// Increase the value 2 times

lcd("Freq: %d Hz

",f);

// Display the sound frequency

sound(f,200);

// Generate the sound signal // from the variable data for 0.2 second

sleep(1000);

// Delay 1 second

}

Code explanation The program starts working in the setup function and repeats to work in the loop function to repeat reading from the KNOB button. Then, the value you have got multiply by 2 to use for the frequency value desired so the value will be in the range of 0 to 2046Hz and the frequency value will be shown at the LCD module.

For the sound generation at the Piezo speaker, the program will space in each second briefly.

Listing L4-2 : sound_02.pde, the sketch file for using the KNOB button on the ATX board to adjust the sound signal frequency

66 Robo-Creator : AT-BOT activity book

Experiment 5 DC motors control Experiment 5.1 Direction control for DC motor driver This experiment demonstrates about direction control for DC motor driver output 0 and 1 of the ATX board. The motor driver will be drive DC motor forward and backward every 3 seconds continually.

Hardware connection  Connect the DC motor #1 with Motor-0 output of the ATX board.  Connect the DC motor #2 with Motor-1 output of the ATX board.

41 ADC1

40 ADC0

46 ADC6

45 ADC5

44 ADC4

5

42 ADC2

4

43 ADC3

START

DC motor #2

3

ATX1.0 r >> >>>> >>> controll er R board USB DATA

2

ON TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

1

E2

KNOB

ADC7

SW1

49

SW2

50

48

SERVO PORT 9

BATTERY LEVEL

10 11 12 13 S

8

+

-

7.2-9V BATT.

0

RESET

14

PC6

15

PC7

MOTOR

DC motor #1

Procedure L5.1.1 Create the new sketch file. Type the Listing L5-1 and save as motor_01.pde file L5.1.2 Compile and upload the sketch to the ATX board.

L5.1.3 Run the program.

DC motor at output 0 and 1 start and reverse direction every 3 seconds.

Robo-Creator : AT-BOT activity book  67

#include <atx.h>

// Include the main library

void setup() { } void loop() { motor(0,70);

// Drive motor-0 with 70% power

motor(1,70);

// Drive motor-1 with 70% power

sleep(3000);

// Delay 3 seconds before change the direction

motor(0,-70);

// Drive motor-0 backward with 70% power

motor(1,-70);

// Drive motor-1 backward with 70% power

sleep(3000);

// Delay 3 seconds before change the direction

}

Code explanation The program repeats to work in the loop function to drive the DC motor of the channel 0 and 1 simultaneously with 70% power equally both. And every 3 seconds reversing direction of rotation will be operated continuously.

Listing L5-1 : motor_01.pde, the sketch file for direction control of DC motor driver of the ATX board. DC motor will reverse direction every 3 seconds continually

Experiment 5.2 Timing control motor In this experiment demonstrates the programming for driving both DC motor at the Motor-0 and 1 output of the ATX board with timing control. Both motors will operate 3 seconds and then stop 3 seconds alternately and continuously.

Hardware connection  Connect the DC motor #1 with Motor-0 output of the ATX board.  Connect the DC motor #2 with Motor-1 output of the ATX board.

Procedure L5.2.1 Create the new sketch file. Type the Listing L5-2 and save as motor_02.pde file L5.2.2 Compile and upload the sketch to the ATX board.

L5.2.3 Run the program.

DC motors at output 0 and 1 start and stop 3 seconds alternately and continually.

68 Robo-Creator : AT-BOT activity book

#include <atx.h>

// Include the main library

void setup() { } void loop() { motor(0,90);

// Drive motor-0 with 90% power

motor(1,90);

// Drive motor-1 with 90% power

sleep(3000);

// Delay 3 seconds

motor_stop(0);

// Stop motor-0

motor_stop(1);

// Stop motor-1

sleep(3000);

// Delay 3 seconds

}

Code explanation The program repeats to work in the loop function to drive the DC motor at channel 0 and 1 simultaneously with the 90% power driving equally both. After 3 seconds, all motors will stop for 3 seconds also and start to rotate again. This will work together seamlessly.

Listing L5-2 : motor_02.pde, the sketch file for timimg control of DC motor driver of the ATX board. DC motor will start and stop every 3 seconds continually

Robo-Creator : AT-BOT activity book  69

Experiment 6 Servo motor control Experiment 6.1 Control position of the servo motor This experiment demonstrates about programming to control the servo motor shaft position. The servo motor is driven to move the shaft to 60 degrees position and stop to lock at this position for 5 minutes. Next, change to the position to 120 degrees and stop to lock at this position for 5 minutes as well. Then, the shaft will be moved to the position of 60 degrees again so that the positions will be switched back and forth like this constantly.

Hardware connection

41 ADC1

40 ADC0

46 ADC6

45 ADC5

44 ADC4

5

42 ADC2

4

43 ADC3

START

 Connect a standard servo motot to servo motor output port 12 of the ATX board

Servo motor

ATX 1.0 r > > >>>> > >> 3

con troll er R boa rd USB DATA

2

ON TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

1

E2

KNOB

ADC7

SW1

49

SW2

50

48

SERVO PORT 9

BATTERY LEVEL

10 11 12 13

STANDARD SERVO MOTOR

S

8

+

-

7.2-9V BATT.

0

RESET

14

PC6

15

PC7

MOTOR

Procedure L6.1.1 Create the new sketch file. Type the Listing L6-1 and save as servo_01.pde file L6.1.2 Compile and upload the sketch to the ATX board.

L6.1.3 Run the program.

The servo motor shaft will move between 60 and 120 degrees position every 5 seconds

70 Robo-Creator : AT-BOT activity book

#include <atx.h>

// Include the main library

void setup() {} void loop() { servo(12,60);

// Drive the servo motor at port 12 to move its shaft to // 60 degrees position

sleep(5000);

// Delay 5 seconds

servo(12,120);

// Drive the servo motor at port 12 to move its shaft to // 120 degrees position

sleep(5000);

// Delay 5 seconds

}

Code explanation The program repeats to work in the loop function to drive a servo motor to move its shaft between the position of 60 and 120 degrees in every 5 seconds.

Listing L6-1 : servo_01.pde, the sketch file for driving a servo motor to control the movement position

Experiment 6.2 Switch-controlled the servo motor position This experiment demonstrates about control the servo motor shaft position by 2 of switch on the ATC board. The SW1 is used to increase the position angle ans SW2 is used to decrease the position angle.

Hardware connection  Connect a standard servo motot to servo motor output port 12 of the ATX board

Procedure L6.2.1 Create the new sketch file. Type the Listing L6-2 and save as servo_02.pde file L6.2.2 Compile and upload the sketch to the ATX board.

L6.2.3 Run the program.

At the LCD display of the ATX controller board show message as follows :

Servo: xxx therefore xxx is servo motor shaft position. Start at 90

Robo-Creator : AT-BOT activity book ď Źď&#x20AC; 71

#include <atx.h> int p=90;

// Include the main library // Declare the position variable // and set the default value as 90

void setup() {} void loop() { servo(12,p); lcd("Servo: %d if(sw1()==0) { p++; if(p>180) { p=0; } sleep(100); } if(sw2()==0) { p-- ; if(p<0) { p=0; } sleep(100);

",p);

// // // //

Drive a servo motor to move the shaft to position that defined by the p variable Show the current position of servo motor shaft Is the SW1 switch pressed ?

// Increase the position value // Is the position more than 180 ? // If the position value more than 180, // set the position value back to 0 // Delay 0.1 second // Is the SW2 switch pressed ? // Decrease the postion value // Is the position lower than 0 ? // If the position value lower than 0, // set the position value as 0 // Delay 0.1 second

} }

Code explanation The program repeats to work in the loop function to drive a servo motor to move its shaft to the position stored in the variable p along with displaying a position value at the LCD module.

Furthermore, there are conditions of verification within the loop as follows: 1. If the SW1 switch is pressed (sw1( ) function returns the value as o) The program responds by adding the p variable value to 1 value and check that exceed 180 or not. If it is exceeded, set the position to start with the new 0. Next, time delay will proceed to not cause the addition of values too fast.

2. If the SW2 switch is pressed (sw2( ) function returns the value as 0) The program responds by reducing the p variable value to 1 value and verifies that the value is below 0 or not. If it is, set the position to start with the new 0 and then time delay.

Listing L6-2 : servo_02.pde, the sketch file for driving a servo motor to control the movement position by SW1 and SW2 switch on the ATX board

72 Robo-Creator : AT-BOT activity book

L6.2.4 Press the SW1 switch The shaft position of the servo motor will be increased 1 value. At the same time, the servo motor shaft will be moved according to the increasing value. When adding the value to 180, the position value will be back to start at the new 0.

L6.2.5 Press the SW2 switch The shaft position of the servo motor will be decreased 1 value. At the same time, the servo motor shaft will be moved according to the decreasing value. When the value is lower than 0, the position value will be back to start at the new 0.

Robo-Creator : AT-BOT activity book  73

Experiment 7 Serial data communication with computers Experiment 7.1 Transmit the serial data to computer This experiment demonstrates about computer interfacing of the ATX controller board. Begins with transmitting the serial data to USB port via the USB to serial converter circuit on the ATX board. The data will be display on the Serial Monitor of Wiring IDE.

41 ADC1

40 ADC0

46 ADC6

45 ADC5

44 ADC4

5

42 ADC2

4

43 ADC3

START

Connect to USB port

3

ATX 1.0 r > > >>>> >>> con troll er R board USB DATA

2

ON TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

1

E2

KNOB

ADC7

SW1

49

SW2

50

48

SERVO PORT 9

BATTERY LEVEL

10 11 12 13 S

8

+

-

7.2-9V BATT.

0

RESET

14

PC6

15 PC7

MOTOR

Procedure L7.1.1 Create the new sketch file. Type the Listing L7-1 and save as uart_01.pde file L7.1.2 Compile and upload the sketch to the ATX board. Still connect the USB cable with USB port of computer.

74 Robo-Creator : AT-BOT activity book

#include <atx.h>

// Include the main library

void setup() {} void loop() { uart("Hello Robot!\r\n");

// Transmit the serial data // to computer with carrier return

sleep(2000);

// Delay 2 seconds

}

Code explanation The program reapeats working in the loop function to transmit some text “Hello Robot!” to display on the Serial Monitor of the computer every 2 seconds continuously.

Listing L7-1 : uart_01.pde, the sketch file for transmitting the serial data to computer of the ATX controller board L7.1.3 Run the program. Click on the

button to open the Serial Monitor of Wiring IDE

The Serial Monitor window appears and dsiplay message Hello Robot! every 2 seconds.

Robo-Creator : AT-BOT activity book ď Źď&#x20AC; 75

Experimenrt 7.2 KNOB data monitoring This experiment demonstrates about transmitting the serial data from reading theKNOB value of the ATX board to shows on the Serial Monitor. It is the simple sensor data monitoring application.

Procedure L7.2.1 Create the new sketch file. Type the Listing L7-2 and save as uart_02.pde file L7.2.2 Compile and upload the sketch to the ATX board. Still connect the USB cable with USB port of computer.

L7.2.3 Run the program. Click on the

button to open the Serial Monitor of Wiring IDE

L7.2.4 Adjust the KNOB button and see the operation at the Serial Monitor of Wiring IDE. The Serial Monitor displays message KNOB: xxx every 0.1 second. Therefore xxx value us 0 to 1023.

#include <atx.h> void setup() {} void loop() { uart("KNOB: %d sleep(100);

// Include the main library

\r\n",knob()); // Transmit the serial data // to computer with carrier return // Delay 0.1 second

}

Code explanation The program repeats to work in the loop function to transmit the KNOB value to KNOB to display on the Serial Monitor of the computer every 0.1 seconds continuously.

Listing L7-2 : uart_02.pde, the sketch file for transmitting the KNOB button of the ATX board to computer

76 Robo-Creator : AT-BOT activity book

Experiment 7.3 Receiving the serial data from computer In this experiment presents about receiving the data from computer via USB port.

The data will be transmitted out from computer by inputing with the SErial Monitor window of Wiring IDE to control the sound generation of the ATX board.

Procedure L7.3.1 Create the new sketch file. Type the Listing L7-3 and save as uart_03.pde file L7.3.2 Compile and upload the sketch to the ATX board. Still connect the USB cable with USB port of computer.

L7.3.3 Run the program. Click on the

button to open the Serial Monitor of Wiring IDE

L7.3.4 Type character of number 1 at the transmit box. Choose the serial data parameter box to No line ending. After that, click on the Send button of the Serial Monitor.

L7.3.5 Observe the operation of the ATX controller board.

The ATX board receives the number 1 data to generates the 500Hz signal with 0.1 second.

7.3.6 Type character of number 2 at the transmit box then click on the Send button of the Serial Monitor.

L7.3.7 Observe the operation of the ATX controller board.

The ATX board receives the number 2 data to generates the 2000Hz signal with 0.5 second.

Robo-Creator : AT-BOT activity book ď Źď&#x20AC; 77

#include <atx.h> char c; void setup() {} void loop() { if(uart_available()) { c = uart_getkey(); if(c=='1') { beep(); } if(c=='2') { sound(2000,500); } } }

// Include the main library // Declare the data variable

// Check the serial data receiving // Store the serial data to the data variable // Is it number 1 data ? // If yes, generate the 500Hz signal with 0.1 second // Is it number 2 data ? // If yes, generate the 2000Hz signal with 0.5 second

Code explanation The program repeats to work in the loop function to receive the serial data from computer.

After the receiving occur, it will be stored data to the c variable and check the value as follows : 1. If the data is the number 1 (from pressing the key 1) The program will respond by generating the 500Hz signal for 0.1 second.

2. If the data is the number 2 (from pressing the key 2) The program will respond by generating the 2000 Hz signal for 0.5 second.

3. If it is another data No response

Listing L7-3 : uart_03.pde, the sketch file for receiving the serial data from computer of the ATX board

78 Robo-Creator : AT-BOT activity book

Robo-Creator : AT-BOT activity book ď Źď&#x20AC; 79

Chapter 6 AT-BOT movement After try out with some experiment to verify the operation of the hardware in the chapter 5. Next, it will be the part of understanding to the mechanical structure of AT-BOT robots and how to move AT-BOT robots. The movement of AT-BOT robots is different from familiar two wheeled mobile robots because an AT-BOT has 4 sets of DC motor gearbox and spike wheels. Therefore, programming to drive robots also needs to be considered the functions of all 4 motors. In this chapter, the content will be presented with examples of programming under C/C++language of Wiring to manage AT-BOT to move in the basic patterns, either moving straight, backward and turning or turning around in various ways.

Left front wheel Motor-0

Right front wheel Motor-3

ON 42 ADC2 41 ADC1 40 ADC0

ADC7 SW1

46 ADC6

10 11 12 13

SW2 48

MOTOR

44 ADC4

50

PC7

BATTERY LEVEL

45 ADC5

49

PC6

START

0

Left back wheel Motor-1

43 ADC3

9

SERVO PORT

S

14 15

ATX 1.0 r > > >>>> > >> con troll er R boa rd

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

KNOB

8 +

-

USB DATA

E2

RESET

7.2-9V BATT.

1

2

3

4

5

Right back wheel Motor-2

Figure 6-1 : Illustration of determination of motors and wheels positions in an AT-BOT

80 Robo-Creator : AT-BOT activity book

6.1 Mechanical structure of AT-BOT An AT-BOT robot has 4 sets of driving wheels and they are arranged according to the positions as in the figure 6-1. Generally, driving AT-BOT robots with all 4 sets of driving wheels can be efficient based on one factor you need to consider. The factor is the friction between touching surface and wheels of a robot. In AT-BOT, we will use the 48:1 DC motor gearboxes and splike wheels. This will make motion good and fast on virtually all surfaces. Torque obtained from the motor sets will be a lot and enough to drive a robot moving up the slop of 20 degrees or rough surfaces.

Connection of each motor with a DC motor driving circuit on the ATX board of an AT-BOT robot detailed as follows  The left front wheel is connected with the Motor-0 output.  The left back wheel is connected with the Motor-1 output  The right back wheel is connected with the Motor-2 output  The right front wheel is connected with the Motor-3 output

6.2 Principles of the movement of AT-BOT 6.2.1 Moving forward To drive an AT-BOT robot to move forward can be done by controlling the DC motor gearboxes of all 4 wheels to turn in the direction that forces the robot to move forward with a stable driving power, such as driving with the power of 70% or 100%, etc. to not cause turning around.

43 ADC3 42 ADC2 41 ADC1 40 ADC0 46 ADC6

14

SW2

45 ADC5

49 48

MOTOR

44 ADC4

50

PC7

15

BATTERY LEVEL

PC6

C r e at o r e > >>> > > > >

S

SW1

+

c o n tr o l l er Rb o a r d

ADC7

10 11 12 13

44 ADC4

5

KNOB

9

45 ADC5

4

SERVO PORT

46 ADC6

3

8

40 ADC0

48

MOTOR

2

-

USB DATA

41 ADC1

50

PC7

1

7.2-9V BATT.

42 ADC2

SW2

15

BATTERY LEVEL

START

0

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

43 ADC3

49

PC6

C r e at o r e > >>> > > > >

14

SW1

+

c o n tr o l l er Rb o a r d

ADC7

10 11 12 13

SERVO PORT

9 S

E2

RESET

USB DATA

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

KNOB

8

-

ON

ON E2

RESET

7.2-9V BATT.

START

0

1

2

3

4

5

Robo-Creator : AT-BOT activity book  81

6.2.2 Moving backwards

To drive an AT-BOT robot to move backwards can do by handling the DC motor gearbox of all 4 wheels to turn in the direction that forces the robot to move backwards with a stable driving power.

ON

ON

E2

43 ADC3

42 ADC2

41 ADC1

40 ADC0

46 ADC6

45 ADC5

8

ADC7

14

SW1

+

46 ADC6

10 11 12 13

SERVO PORT 9

40 ADC0

49

PC6

SW2

48

MOTOR

BATTERY LEVEL

SW2

15 PC7

48

MOTOR

BATTERY LEVEL

50

44 ADC4

15 PC7

45 ADC5

49

PC6

50

44 ADC4

C r e a to r e > >> > > >> >

41 ADC1

KNOB

c o n t ro l l er R b o ar d

42 ADC2

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

43 ADC3

C r e a to r e > >> > > >> >

+ 14

SW1

c o n t ro l l er R b o ar d

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

ADC7

10 11 12 13

SERVO PORT

KNOB

9

5 4 3 2

ON

ON

USB DATA

E2

RESET

USB DATA

E2

RESET

43 ADC3

42 ADC2

41 ADC1

40 ADC0

46 ADC6

45 ADC5

8

ADC7

10 11 12 13

SERVO PORT

9

40 ADC0

ADC7

14

SW1

+

46 ADC6

10 11 12 13

14

SW1

+

49

PC6

SW2

SW2

15 PC7

48

MOTOR

48

MOTOR

BATTERY LEVEL

50

44 ADC4

15 PC7

BATTERY LEVEL

45 ADC5

49

PC6

50

44 ADC4

C r e a to r e > >> >> > > >

41 ADC1

KNOB

c o n t ro l l er R bo a r d

42 ADC2

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

43 ADC3

C r e a to r e > >> >> > > >

9

SERVO PORT

KNOB

c o n t ro l l er R bo a r d

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

8

5

4

3

2

1

USB DATA

RESET

USB DATA

E2

RESET

8

START

START

-

0

5

4

3

2

1

S

Turning point

S

-

0

7.2-9V BATT.

7.2-9V BATT.

START START

1 0 5 4 3 2

S

S

-

1 0

7.2-9V BATT. 7.2-9V BATT.

6.2.3 Turning to the left

There are two formats of the movement, including turning with two wheels and turning around.

6.2.3.1 Turning to the left with two wheels

This movement uses 2 sets of motors and wheels in driving an AT-BOT to turn left by controlling the right front wheel and the right back wheel to rotate forward. Meanwhile, the left front wheel and the left back wheel are stopped, so the robot will be able to turn

left and the rotation point is between the left front wheel and the left back wheel as the diagram below.

82 Robo-Creator : AT-BOT activity book

6.2.3.2 Turning to the left by spining To drive an AT-BOT robot to turn left with another pattern is available by managing the right front wheel and the right back wheel turning forward but the left front wheel and the left back wheel will turn backwards or in the opposite direction. Therefore, AT-BOT robot will turn left with spining and the turning point is at the middle of the robot’s body.

Turning itself to the left by this method will give a high power of the movement but the robot needs more energy as well.

43 ADC3 42 ADC2 41 ADC1 40 ADC0

SW2 48

MOTOR

44 ADC4

50

15 PC7

BATTERY LEVEL

45 ADC5

49

PC6

Turning point

46 ADC6

SW1

14

44 ADC4

C r e a to r e > >>> > > > >

ADC7

SERVO PORT

+

S

5

c o n t ro l l er Rb o a r d

KNOB

10 11 12 13

45 ADC5

4

9

46 ADC6

3

8

40 ADC0

48

2

-

USB DATA

41 ADC1

50

MOTOR

1

7.2-9V BATT.

42 ADC2

SW2

15 PC7

BATTERY LEVEL

START

0

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

43 ADC3

49

PC6

C r e a to r e > >>> > > > >

14

SW1

+

c o n t ro l l er Rb o a r d

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

10 11 12 13

ADC7

SERVO PORT

9 S

E2

RESET

USB DATA

KNOB

8

-

ON

ON E2

RESET

7.2-9V BATT.

START

0

1

2

3

4

5

6.2.4 Turning to the right There are 2 formats of the movement, including turning by 2 wheels and spining.

6.2.4.1 Turning to the right by two wheels To make AT-BOT robot move in this pattern of turning to the right will be done differently from turning left. It is said that controlling the left front wheel and the left back wheel to turn forward but the right front wheel and the right back wheel to stop. Therefore, the robot will be able to turn left and has the rotation point between the right front wheel and the right back wheel.

43 ADC3 42 ADC2 41 ADC1 40 ADC0

SW2

44 ADC4

50 48

MOTOR

BATTERY LEVEL

45 ADC5

49

Turning point

46 ADC6

SW1

PC6

C r e a t o re > >> > > >> >

ADC7

S

14 15 PC7

c o n t r o ll er R b o ar d

KNOB

+

44 ADC4

5

9 10 11 12 13

45 ADC5

4

SERVO PORT

46 ADC6

3

8

40 ADC0

48

2

-

USB DATA

41 ADC1

50

MOTOR

1

7.2-9V BATT.

42 ADC2

SW2

15 PC7

BATTERY LEVEL

START

0

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

43 ADC3

49

PC6

C r e a t o re > >> > > >> >

14

SW1

+

c o n t r o ll er R b o ar d

ADC7

SERVO PORT

9 10 11 12 13 S

E2

RESET

USB DATA

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

KNOB

8

-

ON

ON E2

RESET

7.2-9V BATT.

START

0

1

2

3

4

5

Robo-Creator : AT-BOT activity book  83

6.2.4.2 Turning to the right by spining This driving will be done in the opposite way with turning to the left of the pattern 2 (topic 6.2.4). By controlling the left front wheel and the left back wheel to turn forward but the right front wheel and the right back wheel to be turn backward. The AT-BOT will turn right with spining and the turning point is at the middle of the robot’s body. With this method will give a high power in the movement but need to use more energy as well.

43 ADC3 42 ADC2 41 ADC1 40 ADC0

SW2

44 ADC4

50 48

MOTOR

BATTERY LEVEL

45 ADC5

49

Turning point

46 ADC6

SW1

PC6

C r e a to r e > >>> > > > >

ADC7

SERVO PORT

S

14 15 PC7

c o n t ro l l er Rb o a r d

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

KNOB

+

44 ADC4

5

10 11 12 13

45 ADC5

4

9

46 ADC6

48

3

8

40 ADC0

50

MOTOR

2

-

USB DATA

41 ADC1

SW2

15 PC7

BATTERY LEVEL

1

7.2-9V BATT.

42 ADC2

49

PC6

START

0

E2

43 ADC3

14

SW1

+

C r e a to r e > >>> > > > >

ADC7

10 11 12 13

c o n t ro l l er Rb o a r d

KNOB

9

SERVO PORT

S

RESET

USB DATA

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

8

-

ON

ON E2

RESET

7.2-9V BATT.

START

0

1

2

3

4

5

84 Robo-Creator : AT-BOT activity book

Experiment 8 Wheel driving setting This experiment must be done first for programming to control AT-BOT to move around by presenting the adjustment step of the motor driving to test the basic movement.

AT-BOT are defined all motor connections as follows:  The left front wheel is connected with the Motor-0 output.  The left back wheel is connected with the Motor-1 output  The right back wheel is connected with the Motor-2 output  The right front wheel is connected with the Motor-3 output

In order that this test is in the same way, need to determine the direction of the wheel rotation in each position. In here, a motor of any wheel is driven with a positive value power (+). From the motor function, the motor will turn to the direction that forces a robot to move forward. For example, when you drive the motor from the Motor-1 output with a positive power, the motor shaft will rotate to the direction that makes a robot move forward. If it rotates in the reverse direction, change the polarity connecting of the motor cables at the Motor-1 output to opposite polarity. And then examine remaining 3 motors and wheels with the same method.

ON 43 ADC3 42 ADC2 41 ADC1 40 ADC0 46 ADC6

14

SW1

+

S

SW2

15

48

MOTOR

44 ADC4

50

PC7

BATTERY LEVEL

45 ADC5

49

PC6

C r e a t o r e > >> > > > > >

ADC7

SERVO PORT

9 10 11 12 13

c o n t r o l l er R b o a r d

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

KNOB

8

-

USB DATA

E2

RESET

7.2-9V BATT.

START

0

1

2

3

4

5

Robo-Creator : AT-BOT activity book  85

#include <atx.h> // Include the main library

Code explanation The motor of the channel 0, 1, 2, and 3 are driven with +50% power. Observe the voltage polarity that supplies to the motor from

void setup() {} void loop() { motor(0,50); motor(1,50); motor(2,50); motor(3,50); }

color of the status LED on the motor output of all 4 outputs will have to become green. (If driving with a negative value, the LED will get red). In order to define the polarity connecting of all motor outputs according to the reference.

Apply this pattern of the connection of motor cables on all experiments of this.

Listing L8-1 : motor_test.pde, the sketch file for checking the motor connection of the AT-BOT

Procedure L8.1 Remove all motor cable.

L8.2 Create the new sketch file. Type the Listing L8-1 and save as motor_test.pde file L8.3 Compile and upload the sketch to the ATX board.

L8.4 Connect the left front motor cable to motor-0 output If polarity is correct, robot’s wheel will rotate to the direction that drive the robot forward. If not, swap the connection of motor cable

ON 43 ADC3 42 ADC2 41 ADC1 40 ADC0

ADC7

46 ADC6

14

SW1

+

S

SW2 48

MOTOR

44 ADC4

50

15 PC7

BATTERY LEVEL

45 ADC5

49

PC6

C r e a to r e > >> >> > > >

KNOB

10 11 12 13

SERVO PORT

9

c o n t ro l l er R bo a r d

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

8

-

USB DATA

E2

RESET

7.2-9V BATT.

START

0

1

2

3

4

5

86 Robo-Creator : AT-BOT activity book

L8.5 Connect the left back motor cable to motor-1 output of the AT-BOT If polarity is correct, robot’s wheel will rotate to the direction that drive the robot forward. If not, swap the connection of motor cable

ON 43 ADC3 42 ADC2 41 ADC1 40 ADC0 46 ADC6

14

SW1

S

SW2 50 48

MOTOR

44 ADC4

BATTERY LEVEL

15 PC7

45 ADC5

49

PC6

C r e a to r e > >> >> > > >

ADC7

10 11 12 13

SERVO PORT

9

c o n t ro l l er R bo a r d

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

8

KNOB

+

-

USB DATA

E2

RESET

7.2-9V BATT.

START

0

1

2

3

4

5

L8.6 Connect the right back motor cable to motor-2 output of AT-BOT If polarity is correct, robot’s wheel will rotate to the direction that drive the robot forward. If not, swap the connection of motor cable

ON 43 ADC3 42 ADC2 41 ADC1 40 ADC0 46 ADC6

14

SW1

+

S

SW2 48

MOTOR

44 ADC4

50

15 PC7

BATTERY LEVEL

45 ADC5

49

PC6

C r e a to r e > >> >> > > >

ADC7

10 11 12 13

SERVO PORT

9

c o n t ro l l er R bo a r d

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

KNOB

8

-

USB DATA

E2

RESET

7.2-9V BATT.

START

0

1

2

3

4

5

Robo-Creator : AT-BOT activity book  87

L8.7 Connect the right back motor cable to motor-3 output of AT-BOT If polarity is correct, robot’s wheel will rotate to the direction that drive the robot forward. If not, swap the connection of motor cable

ON 43 ADC3 42 ADC2 41 ADC1 40 ADC0

ADC7

46 ADC6

14

SW1

+

S

SW2 48

MOTOR

44 ADC4

50

15 PC7

BATTERY LEVEL

45 ADC5

49

PC6

C r e a to r e > >> >> > > >

KNOB

10 11 12 13

SERVO PORT

9

c o n t ro l l er R bo a r d

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

8

-

USB DATA

E2

RESET

7.2-9V BATT.

START

0

1

2

3

4

5

Since all motor connections are correct and get the correct result.

User must use these motor connection and polarity mainly on programming for all experiments in this activity book.

88 Robo-Creator : AT-BOT activity book

Experiment 9 Creating the AT-BOT movement function These experiments will present examples of program development to control the AT-BOT’s movement by using the movement control function. Includes forward, backwards, turn left, turn right and stop.

Experiment 9.1 Move forward function This experiment demonstrates about AT-BOT moving forward after the SW1 switch is pressed.

#include <atx.h> // Include the main library void forward() // Function of driving a robot forward { motor(0,40); // Drive the motor of the left front wheel forward with 40% power motor(1,40); // Drive the motor of the left back wheel forward with 40% power motor(2,40); // Drive the motor of the right back wheel forward with 40% power motor(3,40); // Drive the motor of the right front wheel forward with 40% power } void setup() { lcd("SW1 Press!"); // Display the title message sw1_press(); // Wait until the SW1 is pressed } void loop() { forward(); // Drive a robot forward }

Code explanation When the program starts, there is a title message at the ATX board display and then wait for the pressing of SW1. After SW1 is pressed, the program will repeat to work in the loop function to drive motors in order to make the robot move forward constantly.

Addition Program developers can define motor driving power as appropriate. Generally, it is defined that values of the motor driving power in all wheels should be the same. In case that each motor operates differently, a developer needs to test by adjusting a value of driving power of each motor to be not the same in order to find out the best value that makes a robot move best as possible.

Listing L9-1 : robot_move_forward.pde, the sketch file for controlling the AT-BOT to move forward

Robo-Creator : AT-BOT activity book ď Źď&#x20AC; 89

Procedure L9.1.1 Create the new sketch file. Type the Listing L9-1 and save as robot_move_forward.pde file.

L9.1.2 Compile and upload the sketch to the AT-BOT. L9.1.3 Run the program.

AT-BOT display shows the title message ; SW1 Press.

AT-BOT moves forward after the SW1 is pressed.

Experiment 9.2 Move backward function This experiment demonstrates about AT-BOT moving backward after the SW1 switch is pressed.

Procedure L9.2.1 Create the new sketch. Type the Listing L9-2 and save as robot_move_backward.pde file.

L9.2.2 Compile and upload the sketch to the AT-BOT. L9.2.3 Run the program.

AT-BOT display shows the title message ; SW1 Press.

AT-BOT moves backward after the SW1 is pressed.

#include <atx.h> // Include the main library void backward() // Function of driving a robot backward { motor(0,-40); // Drive the motor of the left front wheel backward with 40% power motor(1,-40); // Drive the motor of the left back wheel backward with 40% power motor(2,-40); // Drive the motor of the right back wheel backward with 40% power motor(3,-40); // Drive the motor of the right front wheel backward with 40% power } void setup() { lcd("SW1 Press!"); // Display the title message sw1_press(); // Wait until the SW1 is pressed } void loop() { backward(); // Drive a robot backward }

Listing L9-2 : robot_move_backward.pde, the sketch file for controlling the AT-BOT to move backward

90 Robo-Creator : AT-BOT activity book

Experiment 9.3 Turn left function This experiment demonstrates about AT-BOT turning left after the SW1 switch is pressed.

Procedure L9.3.1 Create the new sketch file. Type the Listing L9-3 and save as robot_turn_left.pde file.

L9.3.2 Compile and upload the sketch to the AT-BOT. L9.3.3 Run the program.

AT-BOT display shows the title message ; SW1 Press.

AT-BOT turns left after the SW1 is pressed.

#include <atx.h> // Include the main library void turn_left() // Function of driving a robot to turn left { motor(0,-40); // Drive the motor of the left front wheel backward with 40% power motor(1,-40); // Drive the motor of the left back wheel backward with 40% power motor(2,40); // Drive the motor of the right back wheel forward with 40% power motor(3,40); // Drive the motor of the right front wheel forward with 40% power } void setup() { lcd("SW1 Press!"); // Display the title message sw1_press(); // Wait until the SW1 is pressed } void loop() { turn_left(); // Drive a robot to turn left }

Listing L9-3 : robot_turn_left.pde, the sketch file for controlling the AT-BOT to turn left

Robo-Creator : AT-BOT activity book ď Źď&#x20AC; 91

Experiment 9.4 Turn right function This experiment demonstrates about AT-BOT turning right after the SW1 switch is pressed.

Procedure L9.4.1 Create the new sketch file. Type the Listing L9-4 and save as robot_turn_right.pde file.

L9.4.2 Compile and upload the sketch to the AT-BOT. L9.4.3 Run the program.

AT-BOT display shows the title message ; SW1 Press.

AT-BOT turns right after the SW1 is pressed.

#include <atx.h> // Include the main library void turn_right()// Function of driving a robot to turn right { motor(0,40); // Drive the motor of the left front wheel forward with 40% power motor(1,40); // Drive the motor of the left back wheel forward with 40% power motor(2,-40); // Drive the motor of the right back wheel backward with 40% power motor(3,-40); // Drive the motor of the right front wheel backward with 40% power } void setup() { lcd("SW1 Press!"); // Display the title message sw1_press(); // Wait until the SW1 is pressed } void loop() { turn_left(); // Drive a robot to turning right }

Listing L9-4 : robot_turn_right.pde, the sketch file for controlling the AT-BOT to turn right

92 Robo-Creator : AT-BOT activity book

Experiment 9.5 Timimg control the robot movement This experiment demonstrates how to control the AT-BOT’s movement by time setting.

Procedure L9.5.1 Create the new sketch file. Type the Listing L9-5 and save as robo_pause.pde file.

L9.5.2 Compile and upload the sketch to the AT-BOT. L9.5.3 Run the program.

AT-BOT display shows the title message ; SW1 Press.

AT-BOT moves forward with 2 seconds and stop for 3 seconds alternate continually after the SW1 is pressed.

#include <atx.h> // Include the main library void forward() // Function of driving a robot forward { motor(0,40); // Drive the motor of the left front wheel forward with 40% power motor(1,40); // Drive the motor of the left back wheel forward with 40% power motor(2,40); // Drive the motor of the right back wheel forward with 40% power motor(3,40); // Drive the motor of the right front wheel forward with 40% power } void setup() { lcd("SW1 Press!"); // Display the title message sw1_press(); // Wait until the SW1 is pressed } void loop() { forward(); // Drive a robot forward sleep(2000); // Delay 2 seconds motor_stop(ALL); // Stop all moving sleep(3000); // Delay 3 seconds }

Listing L9-5 : robo_pause.pde, the sketch file for controlling the ATBOT to move with time setting

Robo-Creator : AT-BOT activity book  93

Chapter 7 Object avoidance by contact Subsequent learning after driving robots is to read values from sensors in order to define the conditions in the movement and the most basic sensor that functions in here is switch. In this chapter, it will mention about application of a switch input board cooperated with AT-BOT so as to detect touching with obstacles and hence a robot will be able to recognize moving to meet obstacles. After this it will process to define movement to be capable of passing through the obstacles.

An important material used in this learning is a switch input board. There is a circuit and a working diagram shown as in the figure 7-1. When there is a pressing of switch, it means touching or bumping with obstacles. The logic output signal will change from the logic ‘1’ to ‘0’ until release the switch or there is no bumping and then the output signal will change back to be ‘1’ again.

With this sensor characteristic, it is used to determine the conditions of the movement for AT-BOT by attaching the switches at the front of a robot body. Once a robot runs to touch or crash with any obstruction, the switch will be pressed and the controller will recognize a change of the output connected with the switch. Therefore, this process will control the robot to move backward and followed by changing a direction of movement.

Only this, the robot will be able to move passed the obstacless.

Output

LED1

LED status

+V

R2 10k R1 510

LED Switch status

S1 Switch

R3 220

DATA

Output GND

When there is no pressing the switch, the DATA pin has a logic ‘1’ from connection of the resistor R2 with the supply voltage.

When pressing the switch, it will cause the connection between the DATA pin and ground. Therefore, the pin DATA will have a logic as ‘0’ and there will be electricity current through the LED 1.

Finally, the LED1 will light up.

Figure 7-1 : Picture, schematic and and circuit explanation of the Switch input board used in AT-BOT

94 Robo-Creator : AT-BOT activity book

Experiment 10 Reading the Switch input board This experiment is a test for function of a switch input board on AT-BOT by which the ATX board will read the status of pressing the switch from the switch input board connected with ADC0 port (or the port 40) to show at the LCD module of the ATX board.

Additional hardware connection  Attach a switch input board at the front of the AT-BOT  Connect the switch unput board cable to ADC0 port or Port 40 of the ATX board on the AT-BOT Switch input board

connect to ADC0

The front of AT-BOT

ON 43 ADC3 42 ADC2 41 ADC1 40 ADC0 46 ADC6

14

SW1

+

S

SW2

15

48

MOTOR

44 ADC4

50

PC7

BATTERY LEVEL

45 ADC5

49

PC6

C r e a to r e > >> >> > > >

ADC7

10 11 12 13

SERVO PORT

9

c o n t ro l l er R bo a r d

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

KNOB

8

-

USB DATA

E2

RESET

7.2-9V BATT.

START

0

1

2

3

4

5

#include <atx.h>

// Include the main library

void setup() {} void loop() { lcd("Switch1: %d ",in(40)); }

// Read the switch input board status from // ADC0/40 port to display on the LCD module // of the AT-BOT

Listing L10-1 : switch1_test.pde, the sketch file for reading status of the Switch input board that interface with AT-BOT at ADC0/40 port

Robo-Creator : AT-BOT activity book ď Źď&#x20AC; 95

Procedure L10.1 Create the new sketch file. Type the Listing L10-1 and save as switch1_test.pde file.

L10.2 Compile and upload the sketch to the AT-BOT. L10.3 Run the program.

AT-BOT display shows the title message :

Switch: x therefore x is the reading data of the Swich input board L10.4 Press and hold the switch and then check the result of the operation.

The status value of the switch (x) will change to 0 and when you release the switch, the result will return to the value of 1 again.

STA

R

T 41 ADC1

4 DC A

5

44

40 ADC0

4

C5 AD

5 A DC 2 442

46 ADC6

3

C6

11 E R 10O PORT SSERV 9 8 89 10 11 12 13

+ 14

2

8

9

ON

USB D ATA

E2

14

PC6

S W1RESET 49

+

50

48

TWI UA RT1 0 SCL 1 SD A 2 R X1 3 TX1

SW2

15

PC7

MOTOR

BATTERY LEVEL

ADC2 ADC64 1 45 A DCA1DC 540 44ADC0 ADC4 42 46

10 11 12 13

SERVO PORT

ADC3 0 4 043A DC

U SB D ATA

E2

15

8

9

PC7

MOTOR

46 A DC 6

10 11 12 13

SERVO PORT BATTERY LEVEL

46 A DC 6

14

SW1

+

PC6

49

40 ADC0

+ 14

S W1

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

ADC 7

10 11 12 13

4 1 A DC 1

10 11 12 13

14

SW1

+

8

SW2

ADC7

15 P C7

48

14

SW1

+

MOTOR

48

MOTOR

BATTERY LEVEL

50

4 4 ADC4

15 P C7

BATTERY LEVEL

SW2

50

4 4 ADC4

9 10 11 12 13

SERV O PORT

KNOB

45 ADC5

PC6

49

45 ADC5

PC6

49

45 ADC5

44 A DC 4

MOTOR PC7

15

BA TTER Y LEVEL

PC6

48

44 A DC 4

S W2

15

PC7

MOTOR

BA TTER Y LEVEL

50

45 ADC5

PC6

49

5 4 3 2 1

43 ADC3

RX

UA 1 3

2

46 ADC6

1

2 DC A

A

40 ADC0

0

2 4

L SC

I SD TW 1

T E SE R

41 ADC1

S

C3 AD

0

AD > 46 > d > > t o rr e > > > > > > > > C0 C r e> a a AD 40 o > 1 c >o n Rtbr o l l e r R b o a DC 48 r d A > 41 0 r e 5 EL USB D ATA e 2 r LEV W Y S R l o O ER T ON O 49 TT t TWIl M UA RT1 BA 1 a 0 SCLo 1 SD A 2 R X1 3 TX1 7 W S r PC eE2 15 t r 6 7 n C DC PC A RT o 1449 ADC7 13 SW1 S W2 50 48 + B KNOB PO 1 X1 12 cRESET NO RT T VO K

TA DA

E2

N

B

O

45 A DC 435 ADC3 44 ADC4 42 A DC 2

US

46 ADC6

-

43

4 0 A DC 0

.

41 ADC1

TT

42 ADC2

41 ADC1

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

42 ADC2

ON TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

9

SERVO PORT

42 ADC2

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

ADC7

c o n t r o l l er R b o a r d

C r e at o r e> >> >> > > >

43 ADC3

SW2 KNOB 50 ADC7 48

c o n t r o l l ecroRnbtoraorldl e r R b o a r d

C r e a t o r e >C>r>e>a>t>o>r>e > > > > > > > >

43 A DC 3

KNOB ADC 7

c o nt r o ll er Rb o a rd c on t r ol l erR b o ar d

C r e a t o r e > > > > > > > > C r e a t o r e > >> > > > > >

43 A DC 3

BA

USB DATA

E2

RESET

USB DATA

E2

8

R ESET KNOB

U SB D ATA

E2

9

SERVO PORT

STAR T START

0 5 4

S

S

-

3

7.2-9V BAT T.

7 .2 -9V B AT T.

KNOB

8

5 3 5 4 3 2

ON

ON

RESET

ON

R ESET

START

2

4 1 STAR T

0

3 S

2

5

4 3 2 2 0 -

S

-

S

-

1

S

-

1 1

0

7.2-9V BATT.

7.2 -9V BAT T.

1 0

START

START

0 5

4

7 .2 -9V B AT T. 7.2-9V BATT.

Obstacle Obstacle Obstacle Obstacle

7.

2-9 V

96 Robo-Creator : AT-BOT activity book

Experiment 11 AT-BOT avoid the obstacle by touching

This experiment demonstrates about programming to controls AT-BOT in order to detect an obstacle by bumping and then change its direction to avoid the obstacle. A touch sensor or a switch input board is applied and installed at the front of a robot according to the experiment 10. There are conditions of the operation as follows: 1. A robot does not find any collision, the robot will move straight forward constantly.

2. A robot is crashed, there will be a loud sound out once. Then, the robot will step backward and change the direction to the left and keep moving forward to avoid the object.

Procedure

L11.1 Create the new sketch file. Type the Listing L10-1 and save as switch1_test.pde file.

L11.2 Compile and upload the sketch to the AT-BOT. Unplug the USB cable from the robot.

L11.3 Place the robot on the floor. Place some obstacle such as box or can to set the demonstration field.

L11.4 Run the program.

AT-BOT display shows the title message : Press SW1

L11.5 Press the SW1 at AT-BOT.

AT-BOT move forward. If it will bump a obstacle, it will step back and change a direction to the left. After that the robot will move forward continuously.

Robo-Creator : AT-BOT activity book ď Źď&#x20AC; 97

#include <atx.h> // Include the main library #define POW 80 // Set the motor power to 60% char mid; // Declare the switch status variable void forward(unsigned int time) // Moving forward function { motor(0,POW); // Drive the Motor-0 forward motor(1,POW); // Drive the Motor-1 forward motor(2,POW); // Drive the Motor-2 forward motor(3,POW); // Drive the Motor-3 forward sleep(time); // Delay for moving forward } void backward(unsigned int time) { motor(0,-POW); // Drive the Motor-0 backward motor(1,-POW); // Drive the Motor-1 backward motor(2,-POW); // Drive the Motor-2 backward motor(3,-POW); // Drive the Motor-3 backward sleep(time); // Delay for moving backward } void turn_left(unsigned int time) { motor(0,-POW); // Drive the Motor-0 backward motor(1,-POW); // Drive the Motor-1 backward motor(2,POW); // Drive the Motor-2 forward motor(3,POW); // Drive the Motor-3 forward sleep(time); // Delay for turning left } void turn_right(unsigned int time) { motor(0,POW); // Drive the Motor-0 forward motor(1,POW); // Drive the Motor-1 forward motor(2,-POW); // Drive the Motor-2 backward motor(3,-POW); // Drive the Motor-3 backward sleep(time); // Delay for turning right } void setup() { lcd("SW1 Press!"); sw1_press(); } void loop() { mid = in(40); if(mid==0) { beep(); backward(500); turn_left(800); } else { forward(1); } }

// Display title message for asking to press the SW1 // Wait until the SW1 is pressed

// Read the switch status to store to the mid variable // Check the switch pressing // If the sensor is pressed, drive a beep once // Move backward 0.5 second // Turn left 0.8 second for avoiding the obstacle

// The robot move forward with 0.001 second

Listing L11-1 : robo_bumper1.pde, the sketch file for demonstration the AT-BOT avoid the obstacle by using one touch sensor (continue)

98 Robo-Creator : AT-BOT activity book

Code explanation The program begins with display the title message for asking the SW1 pressing in order to wait for pressing the switch of SW1 by the sw1_press function. When the SW1 on the AT-BOT is pressed, the program will be able to follow a command in the next line, which is to work in the loop function. It defines to repeat reading a status value of the ADC0/40 port, which is connected with the switch input board or touch sensor. Store the value at the variable mid. Once the switch input board is pressed, it will give the result as ‘0’ and then the program will bring the value of the variable to compare as the following:  The case of if(mind==0) : it is the checking the switch input board is pressed or not. If it is true, this will influence the robot to drive a beep sound and move backward. After that the robot will turn left to avoid an object (the value of time delay will be adjusted by a developer as appropriate).  The case of else : it is inferred that the robot has not found any obstacle. If is true, it will cause the robot to move forward for a short distance.

Listing L10-1 : switch1_test.pde, the sketch file for reading status of the Switch input board that interface with AT-BOT at ADC0/40 port (final)

Robo-Creator : AT-BOT activity book  99

Experiment 12 Reading two touch sensors This experiment purpose is reading the status of two of switch input boards. Now it is called “Touch sensor”. The ATX board will read the status of switch pressing from the switch input board connected with ADC0/40 and ADC2/41 ports to show at the LCD module of the ATX board.

Additional hardware connection  Attach two of the switch input board at the front of the AT-BOT  Connect the switch input board #1 cable to ADC0/40 port of the AT-BOT  Connect the switch input board #2 cable to ADC1/41 port of the AT-BOT Switch input board #1

Switch input board #2

connect to ADC0/40

The front of AT-BOT

connect to ADC1

ON 43 ADC3 42 ADC2 41 ADC1 40 ADC0

ADC7

46 ADC6

14

SW1

+

S

SW2 48

MOTOR

44 ADC4

50

15 PC7

BATTERY LEVEL

45 ADC5

49

PC6

C r e a t o r e > >> > > > > >

KNOB

10 11 12 13

SERVO PORT

9

c o n t ro l l erR b o a r d

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

8

-

USB DATA

E2

RESET

7.2-9V BATT.

START

0

1

2

3

4

5

Procedure L12.1 Create the new sketch file. Type the Listing L12-1 and save as switch2_test.pde file.

L12.2 Compile and upload the sketch to the AT-BOT.

100 Robo-Creator : AT-BOT activity book

#include <atx.h> // Include the main library void setup() {} void loop() { lcd("Switch1: %d #nSwitch2: %d ",in(40),in(41)); // Read the switch input board status from ADC0/40 // and ADC1/41 port to display on the LCD module of the AT-BOT }

Listing L12-1 : switch2_test.pde, the sketch file for reading status of two Switch input board that interface with AT-BOT at ADC0/40 and ADC1/41 port L12.3 Run the program.

AT-BOT display shows the title message : Press SW1 L12.4 Press the SW1 on the AT-BOT. AT-BOT display shows the title message :

Switch1: x Switch2: y therefore x and y are the reading data of the Swich input board #1 and 2 consequently L12.5 Press the Switch input board #1 (at port ADC0/40) and see the operation.

The status value of the switch (x) will change to 0 and after release the switch, the result will return to the value of 1 again.

L12.6 Press the Switch input board #1 (at port ADC1/41) and see the operation.

The status value of the switch (y) will change to 0 and after release the switch, the result will return to the value of 1 again.

T R S TA

5

41 AD C1

43

2 4

E2

AD

C2

43

r

c

o

n

45

RX

A

E2

L

ES R

SC

ET

I SDA TW 1

0

2

AD

C5

1

8

44

4 A DC

9

40 ADC0

AD

C7

RV

8

SE

9

O

10

13

PC6

49

11

RT PO 12

14

SW1

+

+

SW2

15

9

ON

USB DAT A

E2

+

PC6

49

SW2

15

50

PC7

48

MOTOR

48

MOTOR

BAT TERY LEVEL

50

44 AD C4

15 PC7

BATTERY LEVE L

SW2

TWI UART1 0 SCL 1 SDA 2 RX 1 3 TX1

49

45 ADC5

14 PC 6

ADC7 RESET SW1

10 1 1 1 2 13

SERVO PORT

46 ADC6

14

45 ADC5

PC6

49

SW2

15

9

ADC7

10 11 1 2 13

SERVO PORT

KNOB

8

48

44 AD C4

50

PC7

MOTOR

BAT TERY LEVEL

14

SW1

+

PC 6

49

50

SW2 50

15 PC7

14

48

6 PC

MOTOR

MOTOR

BATTERY LEVE L

48

44 ADC4

PC7

BAT TERY LEVEL

46 ADC6 45 ADC5

1 0 1 1 12 1 3

SERVO PORT

KNOB A DC7

B NO K

C6 > AD > 46 > rd > 0 C ADC3 AD 42 AD C2 41 ADC1 > 40 AD C0 a 46 ADC6 45 ADC5 44 AD C4 40 o > b > 48 R > r 50 e V EL e 2 r LE W Cr e RY o a tlo r e > > > > > > > S> TE l 49 t AT 1 r d B cao n to r o l l e r R b o a 7 SW r PC e 15 t

1 A DC

AT D

T WI UA RT1 T1 TX AR 3 0 SC L 1 SDA 2 RX1 3 UTX1 1

C

41

B

ON

46 ADC6 43 AD 45 C3ADC5 42 ADC2 44 ADC4 41 AD C1

RESET

US

US B DATA

C3 AD

ON

40 ADC0

AR T

4

42 ADC2

TWI UART1 0 SCL 1 SDA 2 RX 1 3 TX1

8

KNOB

c o n t r o l l e r R b o acrodn t r o l l e r R b o a r d

C r e a t o r e > > > > > >C>r>e a t o r e > > > > > > > >

43 AD C3

ST

AD C4

USB DAT A

E2

5

AD

44

48

44 AD C4

45 C5

MOTOR

ON

RESE T

4

>

3

MOTO R

3

45 ADC5

>

>

50

PC7

48

44 ADC4

50

1 5 PC 7

40 ADC0

+

46 ADC6

14

SW1

+

2

46 ADC6

> > a

>

SW2

2

15

BATTERY LEVEL

SW2

BATTERY LEVEL

41 ADC1

1 0 11 12 1 3

40 AD C0

1 0 1 1 12 1 3

1

AD C2

>

o

d

49

r

PC6

1

45 ADC5

PC 6

49

42 AD C2

9

SERVO PORT

41 ADC1

SW1

c o n t r o l l er R b o a r d

C re a to r e> >> >> > >>

43 ADC3

TWI UA RT1 0 SC L 1 SD A 2 RX1 3 TX1

8

KNOB A DC 7

42 AD C2

9

SERVO PORT

ADC 7

c o n t r o l l er R b o a r d

Cr e a to r e> >>> > > >>

43 ADC3

TWI UA RT1 0 SCL 1 SDA 2 RX1 3 TX1

8

KNOB

0

C3

40 AD 42 C0

AD

e R b

14

SW1

+

0

14

SW1

+

S

43

41 ADC1

l

r

ADC7

48

10 11 1 2 1 3

L

50

LE VE

SW 2

Y

R

46 ADC6

1 0 1 1 12 13

.

42 ADC2

9

SERV O PORT

KNOB

8

49

MO TO

BA TT ER

40 ADC0

9

SERVO PORT

KNOB

8

TT

US B

TW I 1 SD

7

ADC

P C7

SW 1

41 DAT C A A r DC1 c 40 > > > > C r e ao t oe r a e > >> > AD n t C0 c o n t r tor l lo e r R b o a r d r 46 o e A AD l C6 >

L

43 ADC3

0 SC

PO

KN OB

RV O

MOTO R

US B DATA

E2

US B DATA

E2

RESET

5

M

O

4

3

2

1

5 4 3 2

O N

E 2

US B DATA

T

SE

SE 10

RT

13

15

2 RX U AR 1 T1 3 TX TWI U1ART1 0 SCL 1 SDA 2 RX1 3 TX1

9

12

S

PC 6

48

TWI UART1 0 S CL 1 S DA 2 RX1 3 TX1

50

PC7

15

ON

RESET

ON

S

RE

T. AT BE2

8

11

+ 14

-

46 AD C6 43 ADC3 45 ADC5 42 AD 44C2ADC4 41 ADC1

RESET

9V 27.

ON

40 ADC0

USB DAT A

E2

SW2

BATT ERY LEVE L

PC6

49

MOTOR

MOTOR

-

41 ADC1

ON

+ 14

ADC 7 RES ET SW1

10 11 12 13

44 AD C4

48

45 ADC5

50

PC7

15

48

44 ADC4

50

PC7

STA RT

START

0

5

4

BA

42 AD C2

C r e a t o r e > > > > > >C>r>e a t o r e > > > > > > > >

43 ADC3

9

SERVO P ORT

46 ADC6

SW2

BATTERY LEVEL

45 ADC5

15

BATTERY LEVEL

SW2

ADC7

c o n t r o l l e r R b o acrodn t r o l l e r R b o a r d

8

KNOB

40 ADC0

PC6

49

46 ADC6

PC6

49

3

2

1

3

7.2- 9V BATT.

7.2 -9V BATT.

2

2 - 9V

USB DAT A

41 ADC1

TWI UAR T1 0 SCL 1 SDA 2 RX1 3 TX1

42 ADC2

+ 14

SW1

co nt rol l erRb oa rd

C r e a t o r e > >> > > > > >

43 ADC3

10 1 1 1 2 1 3

40 AD C0

14

S

1

5

4

-

S

-

E2

RESE T

USB DATA

9

SERV O PO RT

41 ADC1

+

START

0

5

4

3

2

1

0

ON

ON

8

KNO B ADC7

42 ADC2

TWI U ART1 0 SCL 1 SDA 2 RX1 3 TX1

10 11 12 1 3

SW1

co ntr ol l erRb oar d

C r e a t o r e > >> > > > > >

43 ADC3

TWI U ART1 0 SCL 1 SDA 2 RX 1 3 TX1

E2

USB DATA

9

5

4

3

2

1

0

0

START

START

7.2 -9V BATT.

7.2 -9V BATT.

START STA RT

1

0 5 4

Obstacle

Obstacle

Obstacle

Obstacle

3

2 1

3

S

S

-

0 5 4 3 2 1 0

2

5

4

7.2 -9V BATT. 7.2 -9V BATT.

S ERVO PORT

START

-

S

-

E2

RESET

ON

8

7.2-9V BATT .

5 4 3 2

1 0

STA RT

START

S

S

-

KNO B ADC7

S

-

S

-

1 0

7.2 -9V BATT. 7.2-9V BA TT. RESET

7.2-9V BATT.

Obstacle Obstacle Obstacle Obstacle

7.

Robo-Creator : AT-BOT activity book  101

Experiment 13 AT-BOT avoid the obstacle with two touch sensors

This experiment demonstrates about programming to using two switch input boards as two of touch sensors. One is installed at the left front side of the AT-BOT. Another one is on the right front side. The operated condition is as follows : 1. A robot does not find any collision, the robot will move straight forward constantly.

2. A robot is crashed on the left side, there will be a loud sound out once. Then, the robot will move backward and change the direction to the right and keep moving forward to avoid the object.

3. A robot is crashed on the right side, there will be a loud sound out once. Then, the robot will move backward and change the direction to the left and keep moving

forward to avoid the object.

TO

R

102 Robo-Creator : AT-BOT activity book

4. A robot is crashed on the front side. Both touch sensors are attacked. There will be a loud sound out once. Then, the robot will move backward and change the direction to the left and keep moving forward to avoid the object.

Obstacle

Obstacle

ON 1

49 S W2

BA TTE

C6 A DC

5

AR

C4

ST

AD

r

T

44

>

>

5

a

>

d

4

9V

AD

45

>

50

48

RY

LE

15

P C7

VE

ADC4

48

MOT OR

P C6

46

>

o

ADC5 44

50

PC 7

-

SW

14

b

45

15

+

C0

>

3

C7

RT 13

SW2

48

MOTOR

44 AD C4

50

PC7

BAT TERY LEVEL

15

SW2

BATTERY LEVEL

ADC5

PC6

49

12

R

2

PO

S

BA TT .

11

er

>

ADC6

RV O

10

>

46

14

SW1

+

9

AD

l

e

40 ADC0

ADC 7

1 0 11 12 1 3

8

OB

l

r

41 ADC1

9

SERVO P ORT

SE

S

C1 AD

o

o

42 ADC2

8

PC6

49

ADC6 45

-

AD

40

2 R UA RT X1 1 3 TX

KN

2

41

t

1

A DC

r

KNOB

46

14

SW1

+

START

t

1

5

40 ADC0

4

42

a

C re a t or e> >>> > >> >

START

C3

e

c o n t r o l l er R b o a r d

A

n

UART1 2 RX 1 3 TX1

E2

o

r

43 AD C3

c

7.2 -9V BA TT.

RE S ET

AD USB D ATA

TWI 0 SCL 1 SDA

DA TA

0 SC TW I L 1 SD

43

E2

43 45 42 44 41 AD C1 AD C6 ADC3ADC5 ADC2ADC4

C

U SB

ON

L

0

ON

RESE T

46

ADC7

10 11 1 2 13 S

40 ADC0

3

42 ADC2 41 ADC1

2

C r e a t o r e > > > > > >C>r>e a t o r e > > > > > > > >

T WI UAR T1 0 SCL 1 SDA 2 RX1 3 TX 1

1

43 AD C3

E2

US B DATA

9

SERVO PORT

-

KNOB

0

8

5

48

MOT OR

4

50

1 5 PC 7

5

SW2

BAT TERY LEVEL

3

ON

PC6

49 7.2-9V BATT .

c o n t r o l l e r R b o acrodn t r o l l e r R b o a r d

UART1 2 RX 1 3 TX1

14

2

TWI 0 SCL 1 SDA

+

ADC4

1

ADC 7 RESE T SW1

1 0 11 12 1 3 S

ST ART

0

E2

9

44

4

-

SERVO PORT

ADC5

48

MOTOR

3

8

45

PC7

2

K NOB

ADC6

15

SW2 50

BA TTERY LEVE L

48

MOTOR

44 AD C4

50

PC7

1

USB D ATA

RESE T

46

PC6

ADC5

15

SW2

BATTERY LEV EL

STA RT

0

7.2-9V BATT .

41 ADC1 40 AD C0

14

SW1 49

+

C r e a t o r e > >> > > > > >

ADC7

10 1 1 12 13 S

43 ADC3 42 AD C2

9

SERVO PORT

46 AD C6 45

c on tr o ll erR b oa r d

TWI UA RT1 0 SCL 1 SD A 2 RX1 3 TX1

8

KNOB

41 ADC1 40 ADC0

PC6

49

C r e a t o r e > >> > > > > >

14

SW1

+

co n tr o ll erR b oa r d

43 ADC3 42 ADC2

TWI UART1 0 SC L 1 SDA 2 RX1 3 TX 1

ADC7

10 11 1 2 13 S

-

US B DATA

E2

US B DATA

E2

9

SERVO PORT

KNOB

8

-

7.2 -9V BA TT.

2-

ON

RESET

ON

RESET

7.2 -9V B ATT.

Obstacle

7.

Obstacle

STA RT

MO

0

1

2

3

4

5

0

1

2

3

TO 4 R

5

Additional hardware connection and construction  Attach 2 of Switch inpiut board at the fronmt of AT-BOT by using the Right angle joiners, Straigh joiners, 3 x 10mm. screws and 3mm. nuts. Attach the sensor at left front and right front side of the robot by doing at an angle about 45 degrees.

- Attach the switch input board #1 at left front side and connect its cable to ADC0/ 40 port of the AT-BOT - Attach the switch input board #2 at right front side and connect its cable to ADC1/41 port of the AT-BOT

Procedure L13.1 Create the new sketch file. Type the Listing L13-1 and save as robo_bumper2.pde.

L13.2 Compile and upload the sketch to the AT-BOT. Unplug the USB cable from the robot.

L13.3 Place the robot on the floor. Place some obstacle such as box or can to set the demonstration field.

L13.4 Run the program.

AT-BOT display shows the title message : Press SW1 L13.5 Press the SW1 on the AT-BOT. Observe the robot operation.

AT-BOT will go straight constantly. If the robot finds a obstacle and there is collision according to the defined condition, AT-BOT will be able to change the direction of movement to avoid the obstacle.

Robo-Creator : AT-BOT activity book ď Źď&#x20AC; 103

#include <atx.h> // Include the main library #define POW 80 // Set the motor power to 60% char left,right; // Declare the switch status variable void forward(unsigned int time) // Moving forward function { motor(0,POW); // Drive the Motor-0 forward motor(1,POW); // Drive the Motor-1 forward motor(2,POW); // Drive the Motor-2 forward motor(3,POW); // Drive the Motor-3 forward sleep(time); // Delay for moving forward } void backward(unsigned int time) { motor(0,-POW); // Drive the Motor-0 backward motor(1,-POW); // Drive the Motor-1 backward motor(2,-POW); // Drive the Motor-2 backward motor(3,-POW); // Drive the Motor-3 backward sleep(time); // Delay for moving backward } void turn_left(unsigned int time) { motor(0,-POW); // Drive the Motor-0 backward motor(1,-POW); // Drive the Motor-1 backward motor(2,POW); // Drive the Motor-2 forward motor(3,POW); // Drive the Motor-3 forward sleep(time); // Delay for turning left } void turn_right(unsigned int time) { motor(0,POW); // Drive the Motor-0 forward motor(1,POW); // Drive the Motor-1 forward motor(2,-POW); // Drive the Motor-2 backward motor(3,-POW); // Drive the Motor-3 backward sleep(time); // Delay for turning right } void setup() { lcd("SW1 Press!"); // Display title message for asking to press the SW1 sw1_press(); // Wait until the SW1 is pressed } void loop() { // Read the left switch status to store to the left variable left = in(40); right = in(41); // Read the right switch status to store to the right variable if(left==1 && right==1) // Check both switch are not pressed (no attack) { forward(1); // Robot move forward short time } else if(left==0 && right==1) // Check only the left switch pressing { beep(); // If the left swith is pressed, // drive a beep sound once backward(500); // Move backward 0.5 second turn_right(800); // Spin right 0.8 second } //for changing the direction of movement

Listing L13-1 : robo_bumper2.pde, the sketch file for demonstration the AT-BOT avoid the obstacle by using two touch sensor (continue)

104 Robo-Creator : AT-BOT activity book

else if(left==1 && right==0) { beep(); backward(500); turn_left(800); } else if(left==0 && right==0) { beep(); backward(500); turn_left(1500);

// Check only the right switch pressing // // // // //

If the left swith is pressed, drive a beep sound once Move backward 0.5 second Spin left 0.8 second for changing the direction of movement

// Check both switch are pressed together // // // // //

If the both swith is pressed, drive a beep sound once Move backward 0.5 second Spin left 1.5 seconds for changing the direction of movement

} }

Code explanation At the beginning of the operation, the program will show the text of Press SW1 at the LCD module to wait for pressing the SW1 switch on the AT-BOT. When the SW1 is pressed, CPU will operate the command in the loop to repeat reading status values of the both switch input boards at ACD0/40 and ADC1/41 to store at the variable of left and right respectively. Any switch board is pressed, this will give the result value as ‘0’ and then the program will take the values of both variables to compare based on the below mentioned 4 cases: Case 1: if(left==1 && right==1) verified whether there is no pressing both switches or not. If it is true (no collision occurred), it will respond a robot to move forward in a short distance because it has not found any obstacle.

Case 2: else if(left==0 && right==1) checked pressing only the left switch, so if it is true (bumping at the left), there will be a response by making a beep sound and a robot will step back to turn right in order to not clash with an obstacle.

Case 3: else if(left==1 && right==0) examined pressing only the right switch, if it is correct (bumping at the right), it will react by a beep sound. Then, a robot will move backward to turn left so it can avoid an obstacle.

Case 4: else if(left==0 && right==0) it is a test of pressing both switches. If it is true (colliding with the front so both switches are pressed simultaneously), there will be 1 rhythm of a sound. Meanwhile, it will cause a robot to reverse and then turn left to avoid an obstacle.

Program developers can modify the values of time delay used to define rhythmic movement freely in each situation appropriately.

Listing L13-1 : robo_bumper2.pde, the sketch file for demonstration the AT-BOT avoid the obstacle by using two touch sensor (final)

Robo-Creator : AT-BOT activity book  105

Chapter 8 AT-BOT Line tracking One mission of learning about programming to control a small autonomous robot is detection and locomotion along lines. Therefore, AT-BOT are able to perform this mission.

Contents in this chapter will start with explanation of function of light reflection sensors which will be applied as line sensors and followed by preparation of field for test, examples of sensor calibration to work efficiently. After this, entering to experimentls of programming with C/C++ language to seek lines, move within the defined areas and move along the lines which are not considered the junction and considered the junction.

Therefore, learners need efforts to understand and perform trials according to sequences because the whole contents are related each and you will have to apply some knowledge from the previous contents to integrate as well.

8.1 Properties of a light reflector : ZX-03R It is a circuit board used to detect reflection of light. It consist of a super bright red LED which functions as a light source and highly sensitive phototransistor which can detect both visible and invisible light (normal light and Infrared light). The phototransistor will get reflected light which is originated from the LED and reflected on the floor. The phototransistor will give different results based on intensity of reflected ligh it gains. Figure 8-1 shows the working process of this sensor when it is applied on white and black floor.

When the supply voltage is applied, the super-bright red LED will be active. The red light is emitted all the time. In part of the receptor or the phototransistor will obtain the red light from the reflection. The phototransistor will get more or less quantity of light depending on whether any object obstacles or not and the ability to reflect red light on that object, which is based on the feature of floor and color of the objects. Smooth white objects can reflect light well, so the light receptor or the phototransistor will obtain a lot of reflected light. As a result the output voltage of the circuit is high accordingly. Meanwhile, black objects reflex less light so the light receptor works less and sents out low voltage. With those features, the circuit boards of the reflected light sensors are installed at the bottom of a robot’s structure to detect surface and lines.

106 Robo-Creator : AT-BOT activity book

SFH310

+V

current

LED

510 10k

OUT

High output voltage GND

Super-bright red LED Photo-transistor White surface

(A) Operation of sensor with the white surface

SFH310

+V

current

LED

510 10k

OUT

Low output voltage GND

Super-bright red LED Photo-transistor Black surface

(B) Operation of sensor with the black surface

Figure 8-1 : Operation of ZX-03R; the reflected light sensors when used to detect a black line and white surface

Robo-Creator : AT-BOT activity book ď Źď&#x20AC; 107

8.2 Line tracking activity preparation 8.2.1 Material preparation for making the demonstration field In the program development to instruct a robot moving along lines by using the light reflection sensor, first thing to do is analyze lines and surface in order to use the data to set conditions and then compare with a reference value from the test of reading of the state of light reflected on lines and field floor which is actually used. The test of reading is based on the differences of light reflection at each surface with different color. White surface is able to reflex light well but dark surface can do less because black color has low ability of light absorption. Learning in this chapter choose the demonstration field which have white surface and black line. Developers have to make this field first.

The demonstration filed of this handbook will be made from Polypropylene board or PP board and black tape. Important materials and tools compose of: 1. White Polypropylene or PP board. Size is 90 x 60cm. However the sizing can change depending on your applications and resoucres.

2. Black electrical tape 1 inches width 2 rolls. It is recommended to buy 3M brand because this brand has high elastic and it can stick curve well.

3. Scissors or a Cutter

108 Robo-Creator : AT-BOT activity book

8.2.2 Installation the light reflector sensors (ZX-03R) for AT-BOT The purpose of application of the ZX-03R light reflector sensors in AT-BOT is to detect surface and lines so the sensors will be installed under a robot body. There are steps mentioned as follows: (1) Attach 3 of ZX-03R sensors with 12-hole Strip joiners by 3 x 10mm. screws and 3mm. nuts. There are 3mm. plastic standoffs separated out between the sensor boards and the Strip joiners.

12-hole Strip joiner Robot chasis 3mm. plastic standoff 25mm. standoff

3 x 40mm. screw ZX-03R 3 x 15mm. screw

ZX-03R

3mm. plastic standoff 3 x 40mm. screw ZX-03R

3mm. nut

3mm. nut

25mm. standoff

3mm. plastic standoff 25mm. plastic standoff

Right ZX-03R is connected to ADC2 port

Middle ZX-03R is connected to ADC1 port 25mm. plastic standoff Left ZX-03R is connected to ADC0 port may be cut if it touch the front wheel

Top view

3mm. nut

Robo-Creator : AT-BOT activity book ď Źď&#x20AC; 109

(2) Turn off power of AT-BOT and then attach the set of the ZX-03R structure from step (1) at the front of the robot chasis by using 2 sets of 25mm. standoffs to cushion and fasten them with 3 x 40mm. screws and 3mm. nuts 2 sets. As the result, the ZX-03R boards are far from the floor about 5mm. Then, plug the cables of the left, middle and right ZX-03R to ADC0, ADC1 and ADC2 port of AT-BOT respectively.

Finally, the AT-BOT is ready for the mission to detect surface and lines.

The objective of this style of installation sensors is to check surface and lines. The sensors can detect both white and black lines including different colors such as purple and yellow, green and red, etc.

8.2.3 Determination of the reference value to separate differences between lines and surface To define the reference value for using in comparison in order to let a robot know that a sensor has found lines or surface, generally it is based on a programming of reading a value from each light reflection sensor to display. Normally, both values have to be quite different.

Programming C/C++ with Wiring to read values from a ZX-03R light reflection sensor of the AT-BOT will use the analog function. It shows result values 0 to 1023.

110 Robo-Creator : AT-BOT activity book



Super-bright red LED Photo-transistor

Value from analog function

White surface

400 to 900

(A) The white surface reading of the ZX-03R sensor



Super-bright red LED Photo-transistor Black line

Value from analog function

10 to 300

(B) The black line reading of the ZX-03R sensor

If the ZX-03R is at the area of black lines, a value will be low and tends towards the value 0.

If the sensor is at the area of a white surface, a value will be high and tends towards the value 1023.

The calculation of the reference value used to identify white surface and black lines will be as follows Reference value = (value from the white surface + value from black lines)/2 For example, if the white surface values is 950 and black lines is 250, so the reference value will be (950+250)/2 = 600 However, in a practical application user may configure to be wider than these but should be in the range of 250 to 950 but should not choose values to be close to 250 and 950 too much.

Robo-Creator : AT-BOT activity book ď Źď&#x20AC; 111

Experiment 14 Determine the reference value for line detection This experiment is a test to find reference values for detecting lines of AT-BOT with 3 of ZX-03R sensors. They are installed in the front and under the structure base of the AT-BOT. The left sensor is connected with ADC0, the middle one connected with ADC1 and the right one connected with ADC2. The result values will be processed and shown at the LCD module of the AT-BOT robot.

The experiment will present and make the understanding about how to find the reference value for distinguish between lines and surface. It is important knowledge for making the line tracking robot.

Make the simple field The test field in this experiment has a white surface and constructed by sticking of black tapes as a quadrangle with curve angles according to the figure below:

The size of this field can be modified as appropriate. In this book, choose a white PP board with the size of 90x60cm. stuck with black tapes to create the curve border in the size of 70x40cm.

112 Robo-Creator : AT-BOT activity book

Hardware connection  Connect ADC0/40 port of AT-BOT with the left front ZX-03R sensor  Connect ADC1/41 port of AT-BOT with the middle front ZX-03R sensor  Connect ADC2/42 port of AT-BOT with the right front ZX-03R sensor

 ZX-03R sensors are attached at bottom of the robot chasis





 ON 43 ADC3 42 ADC2 41 ADC1 40 ADC0 46 ADC6

14

SW1

+

S

SW2 48

MOTOR

44 ADC4

50

15 PC7

BATTERY LEVEL

45 ADC5

49

PC6

C r e a t o r e > >> > > > > >

ADC7

SERVO PORT

9 10 11 12 13

c o n t r o l l er R b o a r d

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

KNOB

8

-

USB DATA

E2

RESET

7.2-9V BATT.

START

0

1

2

3

4

5

#include <atxt.h> // Include the main library void setup() {} void loop() { lcd("L %d M%d #nR %d ",analog(0),analog(1),analog(2)); // Read all sensor value from ADC0, ADC1 and ADC2 port // to display on the AT-BOT display }

Listing L14-1 : reflect_test.pde, the sketch file for reading sensor from ADC0, ADC1 and ADC2 input to display at the AT-BOT

Robo-Creator : AT-BOT activity book  113

Procedure L14.1 Create the new sketch file. Type the Listing L10-1 and save as reflect_test.pde file.

L14.2 Compile and upload the sketch to the AT-BOT. Unplug the USB cable.

L14.3 Run the program.

AT-BOT display shows the title message :

L xxx M yyy R zzz therefore xxx ,yyy and zzz are the digital data from reading the sensor at left, middle and right position of AT-BOT L14.4 Place the robot on the white surface. Read and record the reading values which are displayed on the AT-BOT .

If all 3 sets of the sensing boards read similar values, you will average all values. The value is about 900 in this step from the test.

ZX-03R result data left

mid

right

(ADC0)

(ADC1)

(ADC2)







ON 43 ADC3 42 ADC2 41 ADC1 40 ADC0 46 ADC6

14

SW1

+

S

SW2 48

MOTOR

44 ADC4

50

15 PC7

BATTERY LEVEL

45 ADC5

49

PC6

C r e a t o r e > >> > > > > >

ADC7

SERVO PORT

9 10 11 12 13

c o n t r o l l er R b o a r d

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

KNOB

8

-

USB DATA

E2

RESET

7.2-9V BATT.

START

0

1

2

3

4

5

114 Robo-Creator : AT-BOT activity book

L14.5 Place the robot above the black line and then read and record a measured value which is shown on the LCD module.

All 3 sets of the sensing boards should read similar values. At this step in this test, the average is about 100.

ZX-03R result data left (ADC0)



mid

right

(ADC1)

(ADC2)





ON 43 ADC3 42 ADC2 41 ADC1 40 ADC0 46 ADC6

14

SW1

+

S

SW2 48

MOTOR

44 ADC4

50

PC7

BATTERY LEVEL

15

45 ADC5

49

PC6

C r e a t o r e > >> > > > > >

ADC7

10 11 12 13

SERVO PORT

9

c o nt r o l l erR b o a r d

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

KNOB

8

-

USB DATA

E2

RESET

7.2-9V BATT.

START

0

1

2

3

4

5

L14.6 Calculate a reference value as follows: Reference value = ( Value from the white surface + Value from the black line)/2 = (900+100) / 2 = 500 However, in actual application, possible to define wider values than these but they should be in the range of 100 to 900 and they should not to be close to 100 and 900 too much. From now on, examples will be based on the reference value 500.

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Experiment 15 Frame detection robot This experiment demonstrates about controlling AT-BOT robots to move within a rectangular frame with curve corners surrounded with black lines. This experiment use only 2 of ZX-03R sensors that is left and right front position.

Use only 2 of ZX-03R at left and right position to detect the black line for controlling the robot move within the frame

Procedure L15.1 Create the new sketch file. Type the Listing L15-1 and save as robo_inner.pde file.

L15.2 Compile and upload the sketch to the AT-BOT. Unplug the USB cable.

L15.3 Place the AT-BOT within the frame of the test field that making in Expeirment 14.

L15.4 Run the program.

AT-BOT display shows the title message :

Press SW1 L15.5 Press the SW1 button on the AT-BOT. Observe the robot operation.

AT-BOT will move within the black frame. If the sensor detect the black line, robot will move backward and change direction similar the object avoider robot activity in chapter 7 but changing from inspection of bumping to inspection of black lines and white surface instead.

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#include <atx.h> // Include the main library #define POW 80 // Set the motor power to 60% #define REF 500 // Set the reference value as 500 unsigned int left,right; // Declare the ZX-03R sensor variable void forward(unsigned int time) // Moving forward function { motor(0,POW); // Drive the Motor-0 forward motor(1,POW); // Drive the Motor-1 forward motor(2,POW); // Drive the Motor-2 forward motor(3,POW); // Drive the Motor-3 forward sleep(time); // Delay for moving forward } void backward(unsigned int time) { motor(0,-POW); // Drive the Motor-0 backward motor(1,-POW); // Drive the Motor-1 backward motor(2,-POW); // Drive the Motor-2 backward motor(3,-POW); // Drive the Motor-3 backward sleep(time); // Delay for moving backward } void turn_left(unsigned int time) { motor(0,-POW); // Drive the Motor-0 backward motor(1,-POW); // Drive the Motor-1 backward motor(2,POW); // Drive the Motor-2 forward motor(3,POW); // Drive the Motor-3 forward sleep(time); // Delay for turning left } void turn_right(unsigned int time) { motor(0,POW); // Drive the Motor-0 forward motor(1,POW); // Drive the Motor-1 forward motor(2,-POW); // Drive the Motor-2 backward motor(3,-POW); // Drive the Motor-3 backward sleep(time); // Delay for turning right } void setup() { lcd("SW1 Press!"); // Display title message for asking to press the SW1 sw1_press(); // Wait until the SW1 is pressed } void loop() { left = analog(0); // Read the left sensor data // to store to the variable left right = analog(2); // Read the left sensor data // to store to the variable right if(left>REF && right>REF) // Verify both sensor still not // detect the black line { forward(1); // No line detect, // move forward for short time } else if(left<REF && right>REF) // Only the left sensor detect line ? {

Listing L15-1 : robo_inner.pde, the sketch file for demonstration the AT-BOT move within the black frame by using two line sensors (cont.)

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backward(500); turn_right(800); } else if(left>REF && right<REF) { backward(500); turn_left(800); } else if(left<REF && right<REF) { backward(500); turn_left(1500); }

// If correct, move backward 0.5 second // Spin right 0.8 second to change direction // Only the right sensor detect line ? // If correct, move backward 0.5 second // Spin left 0.8 second to change direction // Both sensors detect the line ? // If detect, move backward 0.5 second // Spin left 1.5 second to change direction

}

Code explanation When the program runs, at the LCD module there is message Press SW1 to wait for pressing the SW1 button. After SW1 is pressed, CPU operate within the loop function to repeat reading values from the ZX-03R sensors at ADC0 (left) and ADC2 (right) input of AT-BOT to store at the variable left and right respectively. The values will be compared with the reference value later. Therefore, the robot would have found the white surface or black lines.

If any ZX-03R sensor has the result value greater than REF (reference value equal 500), the robot will decide that it has found the white surface. On the other hand, if the result value is less than REF, the robot will consider that it has detected black lines already.

Then, the program will compare values of both variables based on 4 cases as follows: 1. if(left>REF && right>REF) : it is verification that the sensors have not detected any line, true or not. If it is true (not found any strip), this will react to the robot to move forward.

2. else if(left<REF && right>REF) : it is checking that the left sensor has found only one line, true or not. If it is true (found a line or a black frame), this will respond to the robot to back and then turn right in order to change the direction of motion.

3. else if(left>REF && right<REF) : it is examination that the right sensor has detected only one line, true or not. If it is true (detected a line or black frame), it will affect the robot to move backwards and then turn left to alter the direction of movement.

4. else if(left<REF && right>REF) : it is checkup that both side sensors have found lines, true or not. It is true (discovered a line or black frame), will take action to the robot moving back and turn left in order to change the direction of locomotion.

Note: REF value for comparing lines and surface in this experiment is 500, which comes from the experiment 14. Developers may have different reference values depending on other external factors, such as the amount of illumination from the sun around a test field, incandescent light bulbs, or other light sources, including distance from sensors to the field floor.

Listing L15-1 : robo_inner.pde, the sketch file for demonstration the AT-BOT move within the black frame by using two line sensors (final)

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Experiment 16 AT-BOT with the Zigzag movement This is an additional example of searching and detecting lines of the AT-BOT by specifying that there are 2 parallel black lines. Then, the robot will be released to move along the direction that is an angle about 45 degrees with a black line and the robot will move straight constantly until it has detected a line and then turns. AT-BOT continues moving forward till it will found a line again, so it will turn to another direction again. Normally, it

at least 30cm.

works like this so on. Therefore, the robot has a route of zigzag motion between both black lines as the following figure.

During the zigzag movement in this experiment, use only 2 of ZX-03R sensors in the left and right front like the experimet 15.

Make the demonstration field Using a PP board with the size of 90x60 cm. from the experiment 14 (or possible other sizes as required but should be large enough to let a robot be able to move conveniently) to be a field of this experiment and stick 2 parallel lines of black tapes with the distance at least 30 centimeters in order to make the robot have enough area in locomotion.

Procedure L16.1 Create the new sketch file. Type the Listing L15-1 and save as robo_pingponf.pde L16.2 Compile and upload the sketch to the AT-BOT. Unplug the USB cable.

L16.3 Place the robot at the start point at an angle about 45 degrees with a black line.

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#include <atx.h> // Include the main library #define POW 80 // Set the motor power to 60% #define REF 500 // Set the reference value as 500 unsigned int left,right; // Declare the ZX-03R sensor variable void forward(unsigned int time) // Moving forward function { motor(0,POW); // Drive the Motor-0 forward motor(1,POW); // Drive the Motor-1 forward motor(2,POW); // Drive the Motor-2 forward motor(3,POW); // Drive the Motor-3 forward sleep(time); // Delay for moving forward } void backward(unsigned int time) { motor(0,-POW); // Drive the Motor-0 backward motor(1,-POW); // Drive the Motor-1 backward motor(2,-POW); // Drive the Motor-2 backward motor(3,-POW); // Drive the Motor-3 backward sleep(time); // Delay for moving backward } void turn_left(unsigned int time) { motor(0,-POW); // Drive the Motor-0 backward motor(1,-POW); // Drive the Motor-1 backward motor(2,POW); // Drive the Motor-2 forward motor(3,POW); // Drive the Motor-3 forward sleep(time); // Delay for turning left } void turn_right(unsigned int time) { motor(0,POW); // Drive the Motor-0 forward motor(1,POW); // Drive the Motor-1 forward motor(2,-POW); // Drive the Motor-2 backward motor(3,-POW); // Drive the Motor-3 backward sleep(time); // Delay for turning right } void setup() { lcd("SW1 Press!"); // Display title message for asking to press the SW1 sw1_press(); // Wait until the SW1 is pressed } void loop() { left = analog(0); // Read the left sensor data // to store to the variable left right = analog(2); // Read the left sensor data // to store to the variable right if(left>REF && right>REF) // Verify both sensor still not // detect the black line { forward(1); // No line detect, // move forward for short time }

Listing L16-1 : robo_pingpong.pde, the sketch file for demonstration the AT-BOT move zigzag or similar pingpong movement by using two line sensors (continue)

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else if(left<REF && right>REF) { turn_right(400); } else if(left>REF && right<REF) { turn_left(400); } else if(left<REF && right<REF) { backward(1); }

// Only the left sensor detect line ? // If correct, spin right 0.4 second // to change the direction // Only the left sensor detect line ? // If correct, spin left 0.4 second // to change the direction // Both sensors detect the line ? // If detect, move backward for short time

} Code explanation Starting the program with show the message to ask pressing the SW1 button at the LCD of AT-BOT. After SW1 is pressed, CPU will start working in the loop function to repeat reading values of the ZX-03R sensors from ADC0 (left) and ADC1 (right) to store at the variable left and right respectively. Verify and check which sensor can detect black lines similar the previois experiment. Then, compare both variable values as follows: 1. if(left>REF && right>REF) : it is verification that both side sensors have not found any line, true or not. If it is true (not found any strip), this will react to the robot to move forward continuously.

2. else if(left<REF && right>REF) : it is checking that the left sensor has found only one line, true or not. In this case, it is interpreted that the robot has found the upper border line. The program will define the robot to turn right to avoid the line. Program developers can modify a delay time value in turning to have a turning angle as required.

3. else if(left>REF && right<REF) : it is examination that the right sensor has detected only one line, true or not. If it is true, in this case will interpret that the robot has found the lower border line. Then, the program will control the robot to turn left to be out of the line.

4. else if(left<REF && right>REF) : it is checkup that the line sensors in both sides have found lines, true or not. If it is true (discovered a line), will react to the robot moving back for a short time to be away from the line.

Moreover, developers may add commands to instruct robots turning around and turn with other different angles in order to create the type of complete zigzag movement, may involving adjusting the position and the distance of the line sensors from the floor and mechanical adjustments as necessary to make the motion of the robot follow the requirement.

Listing L16-1 : robo_pingpong.pde, the sketch file for demonstration the AT-BOT move zigzag or similar pingpong movement by using two line sensors (final)

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L16.4 Run the program.

AT-BOT display shows the title message :

Press SW1 L16.5 Press the SW1 button on the AT-BOT. Observe the robot operation.

The AT-BOT will move straight constantly until it has found a line, it will turn with an angle about 90 degrees. Then, it will go ahead again till it finds a line of another side, so it will turn and walk forward to turn back to another side in a zigzag motion. Normally, the robot will move between black lines of both sides and program developers have to observe whether the movement of the robot and the angle of turning to change a direction are suitable or not. If it is not complete enough, program developers can adjust appropriate delay time value for turning in the program until the function of the robot is satisfied.

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Experiment 17 Line tracking robot using 2 sensors After learning and testing the line detection from the experiment 15 and 16, In this experiment presents the line tracking robot activity by using 2 of ZX-03R sensors. The demonstration field of this experiment is shown in the figure L17-1. The conditions to act the mission as follows: 1. Robot moves along the black line.

2. When detect the junction, robot must stop for 3 seconds .

Figure L17-1 : Illustration of the demonstration field of the experiment 17. It is made from the PP board and black tapes are stuck on it as the pattern from above

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Basic principle of the line tracking robot using 2 of sensors The main purpose of a line tracking robot is to control the robot to move along the line while 2 sensors are located astride the line. Therefore, there will be 4 cases of events, which are used to specify the conditions of functioning as follows:

Case 1 : The robot is in the field lines or bestride the lines

Using 2 of ZX-03R sensors at the left and right front side to control the robot to move along the line.

Left sensor position :

located on the white surface (sensor’s value > reference value)

Right sensor position :

located on the white surface (sensor’s value > reference value)

Operation :

Robot moves straight and delay the time of the motion for a short time.

124 Robo-Creator : AT-BOT activity book

Case 2 : The robot skips a line to the right

ZX-03R result data left (ADC0)

(ADC2)





right

Left sensor position :

located on the black line (sensor’s value < reference value)

Right sensor position :

located on the white surface (sensor’s value > reference value)

Operation :

Robot turn left with a short time to bestride the black line again .

Case 3 : The robot tilts from the route to the left

ZX-03R result data left

right

(ADC0)

(ADC2)





Left sensor position :

located on the white surface (sensor’s value > reference value)

Right sensor position :

located on the black line (sensor’s value < reference value)

Operation :

Robot turn right with a short time to bestride the black line again .

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Case 4 : The robot has found the crossline or may be junction

ZX-03R result data left

right

(ADC0)

(ADC2)





Left sensor position :

located on the black line (sensor’s value < reference value)

Right sensor position :

located on the black line (sensor’s value < reference value)

Operation :

choose the robot to move forward, turn left, turn right, stop or backward as needed.

It is based on the goal of the mission.

Make the demonstration field Using a PP board with the size of 90x60 cm. from the experiment 14 (or possible other sizes as required but should be large enough to let a robot be able to move conveniently) to be a field of this experiment and stick the black tapes following the figure L17-1

Procedure L17.1 Create the new sketch file. Type the Listing L15-1 and save as robo_line1.pde L17.2 Compile and upload the sketch to the AT-BOT. Unplug the USB cable.

L17.3 Place the robot bestride the black line of the field.

L17.4 Run the program.

AT-BOT display shows the title message : Press SW1

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#include <atx.h> #define POW 80 #define REF 500 unsigned int left,right; void forward(unsigned int time) { motor(0,POW); motor(1,POW); motor(2,POW); motor(3,POW); sleep(time); } void backward(unsigned int time) { motor(0,-POW); motor(1,-POW); motor(2,-POW); motor(3,-POW); sleep(time); } void turn_left(unsigned int time) { motor(0,-POW); motor(1,-POW); motor(2,POW); motor(3,POW); sleep(time); } void turn_right(unsigned int time) { motor(0,POW); motor(1,POW); motor(2,-POW); motor(3,-POW); sleep(time); } void setup() { lcd("SW1 Press!"); sw1_press(); } void loop() { left = analog(0); right = analog(2); if(left>REF && right>REF)

// // // // //

Include the main library Set the motor power to 60% Set the reference value as 500 Declare the ZX-03R sensor variable Moving forward function

// // // // //

Drive Drive Drive Drive Delay

the the the the for

Motor-0 Motor-1 Motor-2 Motor-3 moving

forward forward forward forward forward

// // // // //

Drive Drive Drive Drive Delay

the the the the for

Motor-0 Motor-1 Motor-2 Motor-3 moving

backward backward backward backward backward

// // // // //

Drive Drive Drive Drive Delay

the the the the for

Motor-0 backward Motor-1 backward Motor-2 forward Motor-3 forward turning left

// // // // //

Drive Drive Drive Drive Delay

the the the the for

Motor-0 forward Motor-1 forward Motor-2 backward Motor-3 backward turning right

// Display title message // for asking to press the SW1 // Wait until the SW1 is pressed

// // // // // //

Read the left sensor data to store to the variable left Read the left sensor data to store to the variable right Verify both sensor still not detect the black line

{ forward(1);

// If no detect the line, robot moves forward

}

Listing L17-1 : robo_line1.pde, the sketch file for demonstration the AT-BOT moves along the black line by using 2 line sensors (continue)

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else if(left<REF && right>REF) { turn_left(10); } else if(left>REF && right<REF) { turn_right(10); } else if(left<REF && right<REF) { pause(); sleep(3000); forward(300);

// Only the left sensor detect line ? // Spin left 0.01 second // to move to bestride the line again // Only the right sensor detect line ? // Spin right 0.01 second // to move to bestride the line again // Both sensors detect the line ? // // // //

If detect, robot found the crossline Stop movement 3 seconds Move forward 0.3 second to over the crossline

} }

Listing L17-1 : robo_line1.pde, the sketch file for demonstration the AT-BOT moves along the black line by using 2 line sensors (final) L16.5 Press the SW1 button on the AT-BOT. Observe the robot operation.

Robot moves along the black line and stop for 3 seconds when detect the junction.

After that moves along line continually.

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Experiment 18 Line tracking robot using 3 sensors This experiment is continuing of the experiment 17 by adding a ZX-03 sensor to apply as the third line sensor. It will be installed at the middle position between the left and the right sensor (In the experiment 17, if you did not take out the middle sensor at the bottom of robot chasis, you will use it in this study). This is to help the AT-BOT able to detect the crossline or junction better. For the test field, still use the same layout as the experiment 17 as well as the hardware connection. The additional sensor is to connect with ADC1 port of AT-BOT. The functioning conditions of AT-BOT robots in this study include: 1. A robot must move along the black line.

2. When a robot has discovered the crossline, it needs to stop and wait at the junction for 3 seconds. And then, it will move on.

Principles of the line tracking robot by using 3 line sensors There are 6 situations will probably happen in using 3 line sensors. User can apply them on the determination of the functioning conditions as follows:

Case 1 : A robot is in the lines or bestride a line

ZX-03R result data left

mid

right

(ADC0)

(ADC1)

(ADC2)







Left sensor position :

located on the white surface (value > 500)

Middle sensor position :

located on the black line (value < 300)

Right sensor position :

located on the white surface (value > 500)

Operation :

Robot moves straight and delay the time of the motion for a short time.

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Case 2 : A robot goes out of a line to the right

ZX-03R result data left (ADC0)

mid

right

(ADC1)

(ADC2)







Left sensor position :

located on the black line (value < 300)

Middle sensor position :

located on the white surface (value > 500)

Right sensor position :

located on the white surface (value > 500)

Operation :

Robot turn left with a short time to bestride the black line again .

Case 3 : A robot tilts from a route to the left

ZX-03R result data left

mid

right

(ADC0)

(ADC1)

(ADC2)







Left sensor position :

located on tthe white surface (value > 500)

Middle sensor position :

located on the white surface (value > 500)

Right sensor position :

located on the black line (value < 300)

Operation :

Robot turn right with a short time to bestride the black line again .

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Case 4 : A robot has found junction on the left

ZX-03R result data left (ADC0)

mid

right

(ADC1)

(ADC2)







Left sensor position :

located on the black line (value < 300)

Middle sensor position :

located on the black line (value < 300)

Right sensor position :

located on the white surface (value > 500)

Operation :

choose the robot to move forward, turn left, turn right, stop or backward as needed.

It is based on the goal of the mission.

Case 5 : A robot has found junction on the right

ZX-03R result data left

mid

right

(ADC0)

(ADC1)

(ADC2)







Left sensor position :

located on the white surface (value > 500)

Middle sensor position :

located on the black line (value < 300)

Right sensor position :

located on the black line (value < 300)

Operation :

choose the robot to move forward, turn left, turn right, stop or backward as needed.

It is based on the goal of the mission.

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Case 6 : A robot has found a junction, which is a crossline

ZX-03R result data left (ADC0)

mid

right

(ADC1)

(ADC2)







Left sensor position :

located on the black line (value < 300)

Middle sensor position :

located on the black line (value < 300)

Right sensor position :

located on the black line (value < 300)

Operation :

choose the robot to move forward, turn left, turn right, stop or backward as needed.

It is based on the goal of the mission.

Procedure L18.1 Create the new sketch file. Type the Listing L18-1 and save as robo_line2.pde L18.2 Compile and upload the sketch to the AT-BOT. Unplug the USB cable.

L18.3 Place the robot bestride the black line of the field.

L18.4 Run the program.

AT-BOT display shows the title message : Press SW1 L18.5 Press the SW1 button on the AT-BOT. Observe the robot operation.

Robot moves along the black line and stop for 3 seconds when detect the junction.

After that moves along line continually.

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#include <atx.h> #define POW 80 #define REF 500 unsigned int left,middle,right; void forward(unsigned int time) { motor(0,POW); motor(1,POW); motor(2,POW); motor(3,POW); sleep(time); } void backward(unsigned int time) { motor(0,-POW); motor(1,-POW); motor(2,-POW); motor(3,-POW); sleep(time); } void turn_left(unsigned int time) { motor(0,-POW); motor(1,-POW); motor(2,POW); motor(3,POW); sleep(time); } void turn_right(unsigned int time) { motor(0,POW); motor(1,POW); motor(2,-POW); motor(3,-POW); sleep(time); } void setup() { lcd("SW1 Press!"); sw1_press(); } void loop() { left = analog(0);

// // // // //

Include the main library Set the motor power to 60% Set the reference value as 500 Declare the ZX-03R sensor variable Moving forward function

// // // // //

Drive Drive Drive Drive Delay

the the the the for

Motor-0 Motor-1 Motor-2 Motor-3 moving

forward forward forward forward forward

// // // // //

Drive Drive Drive Drive Delay

the the the the for

Motor-0 Motor-1 Motor-2 Motor-3 moving

backward backward backward backward backward

// // // // //

Drive Drive Drive Drive Delay

the the the the for

Motor-0 backward Motor-1 backward Motor-2 forward Motor-3 forward turning left

// // // // //

Drive Drive Drive Drive Delay

the the the the for

Motor-0 forward Motor-1 forward Motor-2 backward Motor-3 backward turning right

// Display title message // for asking to press the SW1 // Wait until the SW1 is pressed

// Read the left sensor data // to store to the variable left mid = analog(1); // Read the middle sensor data // to store to the variable mid right = analog(2); // Read the left sensor data // to store to the variable right if(left>REF && mid<REF && right>REF) // Check the robot bestride the line or not ? { forward(1); // If correct, robot moves forward with a short time }

Listing L18-1 : robo_line2.pde, the sketch file for demonstration the AT-BOT moves along the black line by using 3 line sensors (continue)

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else if(left<REF && mid>REF && right>REF) // Check the robot to move rightward away of the line { turn_left(10); // Spin left 0.01 second for trying to bestride the line again } else if(left>REF && mid>REF && right<REF) // Check the robot to move leftward away of the line { turn_right(10); // Spin right 0.01 second for trying to bestride the line again } else if(left<REF && mid<REF && right<REF) // Check the robot to found the crossline { pause(); // If found, stop movement sleep(3000); // Delay 3 seconds forward(300); // Move forward 3 seconds to over the crossline } else // For another conditions { forward(1); // Move forward with a short time } }

Code explanation There are 4 conditions of the sensor operation to control the AT-BOT movement.

1. if(left>REF && mid<REF && right>REF) : it is checking about the robot still bestride the line or not. If true, robot will move forward with a short time 2. else if(left<REF && mid>REF && right>REF) : it is checking about the robot moves rightward away of the line or not. If true, robot is controlled to spin left with a short time to back to bestride the line again.

3. else if(left>REF && mid>REF && right<REF) : it is checking about the robot moves leftward away of the line or not. If true, robot is controlled to spin right with a short time to back to bestride the line again.

4. else if(left<REF && mid<REF && right<REF) : it is checking about the robot found the crossline or not. If true, it will stop at the junction for 3 seconds after that moves forward 0.3 second to over the crossline.

Listing L18-1 : robo_line2.pde, the sketch file for demonstration the AT-BOT moves along the black line by using 3 line sensors (final)

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Additional conclusion From the experiment 17 and 18, the robot moves along the line with same concept but their difference is the number of line sensors because the test field is not much complexity so the application of only 2 line sensors can accommodate. However, in case that a test field is more complex such as a left junction and a right junction available.

Using 3 line sensors will be more efficient than only 2 sensors. Consideration of comparable cases will be shown as follows:

(1) The left junction case (1.1) Using 2 of line sensors

ZX-03R result data

ZX-03R result data

left (ADC0)

(ADC2)

left (ADC0)

(ADC2)









right

right

The result is only the left sensor detects the black line. It is inconclusive. Now, the robot is moving out of the line to the right or straight to the left junction.

(1.2) Using 3 of line sensors

ZX-03R result data left (ADC0)

mid

right

(ADC1)

(ADC2)







With this techniques, the left and middle sensors will detect lines.

The conclusion is clear that now the robot is moving straight to the left junction.

Robo-Creator : AT-BOT activity book  135

(2) The right junction case (2.1) Using 2 of line sensors

ZX-03R result data

ZX-03R result data

left

right

left

right

(ADC0)

(ADC2)

(ADC0)

(ADC2)









The result is only the right sensor detects the black line. It is inconclusive.

Now, the robot is moving out of the line to the left or straight to the right junction.

(1.2) Using 3 of line sensors

 

















With this techniques, the right and middle sensors will detect lines.

The conclusion is clear that now the robot is moving straight to the right junction.

136 Robo-Creator : AT-BOT activity book

Experiment 19 Advance line tracking robot This experiment expands on the experiment 18 by adding the complexity of the test field and further conditions of movement along lines as shown in the figure L19-1. ATBOT robots have to use 3 line sensors in the operation of this mission. The conditions of the functioning compose of: 1. The robot has to be released from the start point.

2. The robot has to move to pass the left and the right crossroads of the way to the triple junction.

3. When the robot has arrived to the junction, it must turn left and move along the line in clockwise direction.

Creating the test field Using a PP board with the size of 120 x 60cm. or it is possible to use other sizes to build the field but they should be large enough to support the convenient movement of a robot and stick it with black tapes according to the figure L19-1.

About the robot  Use the AT-BOT that is installed 3 of line sensors from the experiment 17 and 18

Procedure L19.1 Create the new sketch file. Type the Listing L18-1 and save as robo_line3.pde L19.2 Compile and upload the sketch to the AT-BOT. Unplug the USB cable.

START

Junction with crossline

Figure L19-1 : The test field of the advance line tracking robot in the experiment 19

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#include <atx.h> #define POW 80 #define REF 500 unsigned int left,middle,right; void forward(unsigned int time) { motor(0,POW); motor(1,POW); motor(2,POW); motor(3,POW); sleep(time); } void backward(unsigned int time) { motor(0,-POW); motor(1,-POW); motor(2,-POW); motor(3,-POW); sleep(time); } void turn_left(unsigned int time) { motor(0,-POW); motor(1,-POW); motor(2,POW); motor(3,POW); sleep(time); } void turn_right(unsigned int time) { motor(0,POW); motor(1,POW); motor(2,-POW); motor(3,-POW); sleep(time); } void setup() { lcd("SW1 Press!"); sw1_press(); } void loop() { left = analog(0);

// // // // //

Include the main library Set the motor power to 60% Set the reference value as 500 Declare the ZX-03R sensor variable Moving forward function

// // // // //

Drive Drive Drive Drive Delay

the the the the for

Motor-0 Motor-1 Motor-2 Motor-3 moving

forward forward forward forward forward

// // // // //

Drive Drive Drive Drive Delay

the the the the for

Motor-0 Motor-1 Motor-2 Motor-3 moving

backward backward backward backward backward

// // // // //

Drive Drive Drive Drive Delay

the the the the for

Motor-0 backward Motor-1 backward Motor-2 forward Motor-3 forward turning left

// // // // //

Drive Drive Drive Drive Delay

the the the the for

Motor-0 forward Motor-1 forward Motor-2 backward Motor-3 backward turning right

// Display title message // for asking to press the SW1 // Wait until the SW1 is pressed

// Read the left sensor data // to store to the variable left mid = analog(1); // Read the middle sensor data // to store to the variable mid right = analog(2); // Read the left sensor data // to store to the variable right if(left>REF && mid<REF && right>REF) // Check the robot bestride the line or not ? { forward(1); // If correct, robot moves forward with a short time } else if(left<REF && mid>REF && right>REF) // Check the robot to move rightward away of the line

Listing L19-1 : robo_line3.pde, the sketch file for demonstration the AT-BOT moves along the black line by using 3 line sensors on the complex route (continue)

138 Robo-Creator : AT-BOT activity book

{ turn_left(10); // Spin left 0.01 second for trying to bestride the line } else if(left>REF && mid>REF && right<REF) // Check the robot to move leftward away of the line { // Spin right 0.01 second for trying to bestride the line turn_right(10); } else if(left<REF && mid<REF && right>REF) // Check the robot to detect the left junction { forward(10); // Move forward 0.01 second to pass the left junction } else if(left>REF && mid<REF && right<REF) // Check the robot to detect the right junction { forward(10); // Move forward 0.01 second to pass the right junction } else if(left<REF && mid<REF && right<REF) // Check the robot to detect the crossline { // Move forward 0.1 second to pass the crossline forward(100); turn_left(200); // Spin left 0.2 second for trying to bestride the line // at the crossline again } }

Code explanation There are 6 conditions of the sensor operation to control the AT-BOT movement.

1. if(left>REF && mid<REF && right>REF) : it is checking about the robot still bestride the line or not. If true, robot will move forward with a short time 2. else if(left<REF && mid>REF && right>REF) : it is checking about the robot moves rightward away of the line or not. If true, robot is controlled to spin left with a short time to back to bestride the line again.

3. else if(left>REF && mid>REF && right<REF) : it is checking about the robot moves leftward away of the line or not. If true, robot is controlled to spin right with a short time to back to bestride the line again.

4. else if(left<REF && mid<REF && right>REF) : it is checking about the robot detect the left junction or not. If true, robot will move forward to pass this junction.

5. else if(left>REF && mid<REF && right<REF) it is checking about the robot detect the right junction or not. If true, robot will move forward to pass this junction.

6. else if(left<REF && mid<REF && right<REF) : it is checking about the robot found the crossline or not. If true, robot will move forward 0.1 second and turn left 0.3 second after that back to check all line tracking conditions continually

Listing L19-1 : robo_line3.pde, the sketch file for demonstration the AT-BOT moves along the black line by using 3 line sensors on the complex route (final)

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L19.3 Place the robot bestride the black line of the field.

L19.4 Run the program.

AT-BOT display shows the title message : Press SW1 L18.5 Press the SW1 button on the AT-BOT. Observe the robot operation.

The robot AT-BOT will move along the black line until the robot has found the triple junction, it will turn left and move along the curve in the clockwise direction constantly.

Start

Junction with crossline

More information From the previous experiments, the test fields have black strips and white surface.

If you will change to black surface and white lines, programming to control functioning will be able to use the principles of line and surface analysis of the experiment 14 and the principles of driving robots from the experiment 15 to 18 as guidelines of program development.

For example, if you would like to test that a robot has found any crossline or not.

In the case that the field surface is white and the strips are black, apply this condition to check. else if(left<REF && mid<REF && right<REF) But if the field surface is black and the strips are white, use this condition to verify. else if(left>REF && mid>REF && right>REF) Because strips have become white, if read a value from a line sensor of each position and it shows that the value is greater than the reference value. Hence, the line sensor of that position has found a white line.

140ď&#x20AC; ď Źď&#x20AC; Robo-Creator : AT-BOT activity book

Experiment 20 Line tracking robot with the white line mission This experiment represents a guideline of the control program development for ATBOT to move along the white lines on a black surface. The appearance of the test field in this experiment is opposite to that of the experiment 15 to 19, by which the test field in this trial has the same feature with which of the experiment 18 but colors are changed that black lines converts to white lines and the white surface change to black surface as demonstrated in the figure L20-1.

The conditions of functioning include: 1. The robot must move along the white line.

2. When the robot detects the crossline, it will have to stop and wait for 3 seconds approximately and then it will move on.

Making the test field Using a black PP board in the size of 90x60 cm. (possible other sizes as you wish but the size should be large enough that the robot can move around comfortably) as the field surface and stick with white tape to create a curve frame and 2 points of the intersections in accordance with the example in the figure L20-1.

Figure L20-1 : The test field for Line tracking robot in the experiment 20

Robo-Creator : AT-BOT activity book  141

Principles of the line tracking robot with white line by using 3 line sensors There are 6 situations will probably happen in using 3 line sensors. User can apply them on the determination of the functioning conditions as follows:

Case 1 : A robot is in the lines or bestride a line

ZX-03R result data left left (ADC0)

mid

right

(ADC1)

(ADC2)







Left sensor position :

located on the black line (value < 300)

Middle sensor position :

located on the white surface (value > 500)

Right sensor position :

located on the black line (value < 300)

Operation :

Robot moves straight and delay the time of the motion for a short time.

Case 2 : A robot goes out of a line to the right

ZX-03R result data left

mid

right

(ADC0)

(ADC1)

(ADC2)







Left sensor position :

located on the white surface (value > 500)

Middle sensor position :

located on the black line (value < 300)

Right sensor position :

located on the black line (value < 300)

Operation :

Robot turn left with a short time to bestride the black line again .

142 Robo-Creator : AT-BOT activity book

Case 3 : A robot tilts from a route to the left

ZX-03R result data left (ADC0)

mid

right

(ADC1)

(ADC2)







Left sensor position :

located on tthe black line (value < 300)

Middle sensor position :

located on the black line (value < 300)

Right sensor position :

located on the white surface (value > 500)

Operation :

Robot turn right with a short time to bestride the black line again .

Case 4 : A robot has found junction on the left

ZX-03R result data left

mid

right

(ADC0)

(ADC1)

(ADC2)







Left sensor position :

located on the white surface (value > 500)

Middle sensor position :

located on the white surface (value > 500)

Right sensor position :

located on the black line (value < 300)

Operation :

choose the robot to move forward, turn left, turn right, stop or backward as needed.

It is based on the goal of the mission.

Robo-Creator : AT-BOT activity book  143

Case 5 : A robot has found junction on the right

ZX-03R result data left (ADC0)

mid

right

(ADC1)

(ADC2)







Left sensor position :

located on the black line (value < 300)

Middle sensor position :

located on the white surface (value > 500)

Right sensor position :

located on the white surface (value > 500)

Operation :

choose the robot to move forward, turn left, turn right, stop or backward as needed.

It is based on the goal of the mission.

Case 6 : A robot has found a crossline

ZX-03R result data left

mid

right

(ADC0)

(ADC1)

(ADC2)







Left sensor position :

located on the black line (value < 300)

Middle sensor position :

located on the black line (value < 300)

Right sensor position :

located on the black line (value < 300)

Operation :

choose the robot to move forward, turn left, turn right, stop or backward as needed.

It is based on the goal of the mission.

144 Robo-Creator : AT-BOT activity book

Procedure L20.1 Create the new sketch file. Type the Listing L20-1 and save as robo_line4.pde L20.2 Compile and upload the sketch to the AT-BOT. Unplug the USB cable.

L20.3 Place the robot bestride the white line of the field.

L20.4 Run the program.

AT-BOT display shows the title message : Press SW1 L20.5 Press the SW1 button on the AT-BOT. Observe the robot operation.

Robot moves along the white line and stop for 3 seconds when detect the junction.

After that moves along line continually.

#include <atx.h> #define POW 80 #define REF 500 unsigned int left,middle,right; void forward(unsigned int time) { motor(0,POW); motor(1,POW); motor(2,POW); motor(3,POW); sleep(time); } void backward(unsigned int time) { motor(0,-POW); motor(1,-POW); motor(2,-POW); motor(3,-POW); sleep(time); } void turn_left(unsigned int time) { motor(0,-POW); motor(1,-POW); motor(2,POW); motor(3,POW); sleep(time); } void turn_right(unsigned int time) { motor(0,POW); motor(1,POW); motor(2,-POW);

// // // // //

Include the main library Set the motor power to 60% Set the reference value as 500 Declare the ZX-03R sensor variable Moving forward function

// // // // //

Drive Drive Drive Drive Delay

the the the the for

Motor-0 Motor-1 Motor-2 Motor-3 moving

forward forward forward forward forward

// // // // //

Drive Drive Drive Drive Delay

the the the the for

Motor-0 Motor-1 Motor-2 Motor-3 moving

backward backward backward backward backward

// // // // //

Drive Drive Drive Drive Delay

the the the the for

Motor-0 backward Motor-1 backward Motor-2 forward Motor-3 forward turning left

// Drive the Motor-0 forward // Drive the Motor-1 forward // Drive the Motor-2 backward

Listing L20-1 : robo_line4.pde, the sketch file for demonstration the AT-BOT moves along the white line by using 3 line sensors (continue)

Robo-Creator : AT-BOT activity book ď Źď&#x20AC; 145

motor(3,-POW); sleep(time); } void setup() { lcd("SW1 Press!"); sw1_press(); } void loop() { left = analog(0);

// Drive the Motor-3 backward // Delay for turning right

// Display title message // for asking to press the SW1 // Wait until the SW1 is pressed

// Read the left sensor data // to store to the variable left mid = analog(1); // Read the middle sensor data // to store to the variable mid right = analog(2); // Read the left sensor data // to store to the variable right if(left<REF && mid>REF && right<REF) // Check the robot bestride the line or not ? { forward(1); // If correct, robot moves forward with a short time } else if(left>REF && mid<REF && right<REF) // Check the robot to move rightward away of the line { // Spin left 0.01 second for trying to bestride the line again turn_left(10); } else if(left<REF && mid<REF && right>REF) // Check the robot to move leftward away of the line { // Spin right 0.01 second for trying to bestride the line again turn_right(10); } else if(left>REF && mid>REF && right>REF) // Check the robot to found the crossline { pause(); // If found, stop movement sleep(3000); // Delay 3 seconds forward(300); // Move forward 3 seconds to over the crossline }

}

Listing L20-1 : robo_line4.pde, the sketch file for demonstration the AT-BOT moves along the white line by using 3 line sensors (final)

146 Robo-Creator : AT-BOT activity book

Robo-Creator : AT-BOT activity book  147

Chapter 9 AT-BOT with touchless object avoiding In this chapter, it will present the application of a sensing module and a distance measurement with the infrared distance sensor or Infrared ranger GP2D120 with AT-BOT. .

As the result, the AT-BOTs have ability to detect objects without contact with objects.

Therefore, the robots are able to go straight or avoid more wisely.

9.1. The characteristics of the module GP2D120 The GP2D120 is the infrared distance sensing module, which has three used pins composed of the power supply pin (Vcc), the ground pin (GND), and the output voltage pin (Vout). Reading voltage values from GP2D120 will have to wait until the preparation phase is finished by which it takes about between 32.7 and 52.9 milliseconds (1 millisecond equals 0.001 seconds). Hence, the reading of the voltage should wait until after the first period.

The output voltage of GP2D120 at the distance 30cm. with the power supply +5V is in the range from 0.25 to 0.55V and the median is 0.4V. Therefore, the transition period of the output voltage at the distance 4cm. is 2.25V ± 0.3V.

Infrared LED

Infrared Receiver

Output voltage (V) 2.8 2.4 2.0

GP2D120

1.6

Vout GND Vcc

1.2 0.8 0.4

Supply

0 38.3±9.6 ms

Measurement

Vout

1st measure

Not stable

0

4

8

12

16

20

24

28

32

Distance (cm) 2nd measure

1st output

n measure

2nd output

n output

5 ms

Figure 9-1 : Body, Pin assignment and Characteristic graph of the Infrared ranger GP2D120

148 Robo-Creator : AT-BOT activity book

9.2 How to install the GP2D120 with AT-BOT From the chapter 7, AT-BOT can keep away from the obstacles by touching or bumping. As this chapter, the contents will focus on the ability development of AT-BOT to another level by using the GP2D120 module to help with the detection of the distance from obstacles in order to let the robots capable of getting away from obstruction without touching.

The installation of the GP2D120 can be done as follows: (1) Attach a right-angle joiner with the front of the robot at the middle with screws 3 x 10mm. screws and 3mm. nuts.

(2) Fasten a 5-hole strip joiner on the right-angle joiner from the first step with 3 x 10mm. screws and 3mm. nuts at the 3rd hole (the middle) of the strip joiner.

(3) Join the GP2D120 with the strip joiner by 2 sets of 3 x 10mm. screws and 3mm. nuts by which the screws will be strung through the holes of the wings used to fasten the module and the notches at the end of the strip joiner.

GP2D120 module GP2D120

Front of the AT-BOT

GP2D120

43 ADC3 42 ADC2 41 ADC1 40 ADC 0 46 ADC6

SW1 SW2

45 ADC5

49

44 ADC4

50 48

MOTOR

BATTERY LEVEL

C r e a t o r e > >> > > > > >

ADC7

SERVO PORT

PC6 15 PC7

c o n t r o l l er R b o a r d

KNOB

S

14

44 ADC4

5

+

45 ADC5

4

9 10 11 12 13

46 ADC6

3

8

40 ADC 0

48

2

-

USB DATA

41 ADC1

50

MOTOR

1

7.2-9V BATT.

42 ADC2

SW2

15 PC7

BATTERY LEVEL

START

0

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

43 ADC3

49

PC6

C r e a t o r e > >> > > > > >

14

SW1

+

c o n t r o l l er R b o a r d

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

ADC7

SERVO PORT

9 10 11 12 13 S

E2

RESET

USB DATA

KNOB

8

-

ON

ON E2

RESET

7.2-9V BATT.

connect to ADC3

START

0

1

2

3

4

5

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(4) Plug the signal cable of the GP2D120 to ADC3 port of the AT-BOT robot that can detect the obstacles without any contact and be ready for the programming later on.

9.3 gp2d120_lib.h - the library for GP2D120 The gp2d120_lib.h file contains an instruction set or a C/C++ language program function to perform the GP2D120 module. Before running a function in this library, developers have to append the library file at the beginning of the program with the command below. #include <gp2d120_lib.h>

9.3.1. Hardware connection Because the GP2D120 is a sensor that shows the result as DC voltage related with a measured distance. Starting the use of the module should connect with any analog input of the AT-BOT. Includes ADC0 to ADC6.

9.3.2 getdist function In the gp2d120_lib.h library , there is a function to read a measured distance from the GP2D120 in the unit of centimeter.

Syntax

unsigned int getdist(char adc_ch) Parameter adc_ch : used to define analog input connecting with the GP2D120.

Return value The distance in the centimeter unit.

150 Robo-Creator : AT-BOT activity book

Experiment 21 Distance meaturement by GP2D120 This experiment is a programming to read distance values from the module GP2D120 by which the readable values are shown at the LCD module of AT-BOT.

Additional hardware connection  AT-BOT robot already installed with the GP2D120 module and connect to ADC3 port.

Procedure L21.1 Create the new sketch file. Type the Listing L21-1 and save as gp2d120_test.pde L20.2 Compile and upload the sketch to the AT-BOT. Unplug the USB cable. #include <atx.h> // #include <gp2d120_lib.h> // unsigned int dist; // void setup() {} void loop() { dist = getdist(3); // if(dist>=4 && dist<=32) // { lcd(“Distance: %d cm “,dist); // } else { lcd(“Out of Range! “); // // } sleep(100); // }

Include the main library Include the GP2D120 library Declare the distance measurment variable

Read value from GP2D120 at ADC3 input Compare with the reference value Show the distance at AT-BOT’s display

Show the warning message when the measured data is

out of range

Delay 0.1 second

Code explanation The distance value that read from GP2D120 with getdist function is stored in the variable dist. Then, the value will be analyzed whether it is in the range of 4 to 32cm. or not before displayed at the LCD module. If the value is less than 4 and greater than 32, it is considered that the data is not reliable. After this, the message as Out of Range! will be displayed at the LCD module.

Listing L21-1 : gp2d120_test.pde, the sketch file for reading the distance measurement from GP2D120

Robo-Creator : AT-BOT activity book  151

L21.3 Run the program.

AT-BOT display shows the title message :

Distance: xxx cm therefore xxx is the distance value in centimetre unit. and displays the message

Out of Range! when the distance value is out of the range 4 to 32cm.

L21.4 Put an object or your hand to block in the front of the GP2D120 in the operating distance, which is 4 to 32 cm. Then, move in and away the object from the GP2D120.

Finally, monitor the readable distance value at the LCD module.

If the object is in the operating distance of the GP2D120, at the LCD module, there will be a display of the distance value in centimetre. But if the object is not in the operating distance, at the LCD module will be displayed the message Out or Range!, instead.

4cm.

7.2-9V BATT.

14

PC6

15 PC7

MOTOR

+ S

8

9

10 11 12 13

BATTERY LEVEL

SERVO PORT

0 RESET

KNOB

ADC7

SW1

49

SW2

50

48

1

move object

E2

TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

ON USB DATA

3

GP2D120

2

c o n t r o l l er R b o a r d C r e a t o r e > >> > > > > > 4 43 ADC3

42 ADC2

41 ADC1

40 ADC0

46 ADC6

45 ADC5

44 ADC4

5

START

connect to ADC3

32cm.

152 Robo-Creator : AT-BOT activity book

Experiment 22 Touchless object avoiding robot This is the ability development of AT-BOT robos. Previously, AT-BOT used to avoid obstacles by bumping. However, this experiment is different from the mentioned experiment that this experiment will use the GPD120 sensor to help for detecting and avoiding the obstacles without contact. There are conditions of functioning as follows: 1. In case that a robot does not detect any obstruction in the distance of 14 cm.

The robot will move forward.

2. In case that a robot finds obstruction in the distance less than 14 cm. The robot will move backwards and then turn left to change the movement direction.

Procedure L22.1 Create the new sketch file. Type the Listing L22-1 and save as robo_ranger.pde L22.2 Compile and upload the sketch to the AT-BOT. Unplug the USB cable.

L22.3 Place the robot on the floor. Place some obstacle such as box or can to set the demonstration field.

L22.4 Run the program.

AT-BOT display shows the title message : Press SW1 L18.5 Press the SW1 button on the AT-BOT. Observe the robot operation.

The AT-BOT will go straight constantly. When the robot will be able to detect obstruction, it will reverse and turn left. After that, the AT-BOT will move forward in order to avoid the obstruction. If the robot turns around and finds an object, it will go backward again and turn left. The pattern will be repeated until the robot will be able to pass objects and move straight later on.

Obstacle

Obstacle

Obstacle

Obstacle

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#include <atx.h> // Include the main library #include <gp2d120_lob.h> // Include the GP2D120 library #define POW 80 // Set the motor power to 80% unsignd int dist; // Declare the distance variable void forward(unsigned int time) // Moving forward function { motor(0,POW); // Drive the Motor-0 forward motor(1,POW); // Drive the Motor-1 forward motor(2,POW); // Drive the Motor-2 forward motor(3,POW); // Drive the Motor-3 forward sleep(time); // Delay for moving forward } void backward(unsigned int time) { motor(0,-POW); // Drive the Motor-0 backward motor(1,-POW); // Drive the Motor-1 backward motor(2,-POW); // Drive the Motor-2 backward motor(3,-POW); // Drive the Motor-3 backward sleep(time); // Delay for moving backward } void turn_left(unsigned int time) { motor(0,-POW); // Drive the Motor-0 backward motor(1,-POW); // Drive the Motor-1 backward motor(2,POW); // Drive the Motor-2 forward motor(3,POW); // Drive the Motor-3 forward sleep(time); // Delay for turning left } void turn_right(unsigned int time) { motor(0,POW); // Drive the Motor-0 forward motor(1,POW); // Drive the Motor-1 forward motor(2,-POW); // Drive the Motor-2 backward motor(3,-POW); // Drive the Motor-3 backward sleep(time); // Delay for turning right } void setup() { lcd("SW1 Press!"); // Display title message for asking to press the SW1 sw1_press(); // Wait until the SW1 is pressed } void loop() { dist = getdist(3); // Read the distance from GP2D120 at ADC3 input if(dist>=4 && dist<15) // Found the object within 4 to 14cm. or not ? { backward(500); // If found, move backward 0.5 second turn_left(800); // Spin left 0.8 second } // to change the movement direction else { forward(1); // Move forward with a short time } }

Listing L22-1 : robo_ranger.pde, the sketch file for demonstration the AT-BOT avoids the object without contact by using GP2D120 sensor (continue)

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Code explanation At the beginning of the program, there will be a display of the text Press SW1 at the LCD module. When pressing the SW1 is done, the CPU will operate in the loop function to repeat reading values from the GP2D120, which is connected to the ADC3 input.

Those values will be collected at the variable dist. Then, the program will take distance values to compare based on these cases: 1. if(dist>=4 && dist<15) : it is verification that if the robot finds an object in the range of 4 to 14 cm. or not. If it is true (a barrier present), the program will respond the robot by moving backward and turning left to avoid the obstruction.

2. else : if the condition of the case 1 is not true, that is meant that there is no barrier in the interesting distance, so the AT-BOT is designed to move forward.

More information The development of the control program for AT-BOTs cooperated with the GP2D120 will run the getdist function from the gp2d120_lib.h library to read distance values from barriers in the centimetre.

Listing L22-1 : robo_ranger.pde, the sketch file for demonstration the AT-BOT avoids the object without contact by using GP2D120 sensor (final)

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Chapter 10 AT-BOT with Servo motor In this chapter, it will introduce the control of servo motors of the AT-BOT. It can drive 6 of 4.8 to 6V R/C servo motors through the ports 8 to 13.

10.1 Servo motor introduction Figure 10-1 shows a drawing of a Standard Servo. The plug is used to connect the servo motor to a power source (Vdd and Vss) and a signal source (a microcontroller I/O pin). The cable conducts Vdd, Vss and the signal line from the plug into the servo motor.

The horn is the part of the servo that looks like a four-pointed star. When the servo is running, the horn is the moving part that the microcontroller controls. The case contains the servo’s control circuits, a DC motor, and gears. These parts work together to take high/low signals from the microcontroller and convert them into positions held by the servo horn.

Figure 10-2 shows the servo motor cable assignment. It has 3 wires with difference color; Black for GND or Vss or Negative pole, Red for Vdd or Servo motor supply voltage and White (sometime is yellow or brown) wire for signal.

The servo motor plug standard has 2 types; S-type and J-type are shown in the figure 10-3.

Horn Plug

Cable

STANDARD SERVO MOTOR

Case

Figure 10-1 : Standard servo motor physical

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(a) S-type plug

(b) J-type plug

Figure 10-2 : Standard Servo motor Figure 10-3 : Standard Servo motor cable assignment plug type Controlling of the servo motors is used to pulse controlling. The control pulse is positive going pulse with length of 1 to 2 ms which is repeated about 50 to 60 times a second. You can check the details in the figure 10-4. Start by generating a pulse a period 20 millisecond and adjust the positive pulse width 1 millsecond. The servo motor will move the horn to last left position. The pulse width 1.5 millisecond move the servo horn to center and pulse width 2 millsecond causes the servo horn to last right position.

The important specification of servo motor are 2 points, Speed or Servo turn rate or transit time and Torque. The servo turn rate, or transit time, is used for determining servo rotational velocity. This is the amount of time it takes for the servo to move a set amount, usually 60 degrees. For example, suppose you have a servo with a transit time of 0.17sec/ 60 degrees at no load. This means it would take nearly half a second to rotate an entire 180 degrees. More if the servo were under a load. This information is very important if high servo response speed is a requirement of your robot application. It is also useful for determining the maximum forward velocity of your robot if your servo is modified for full rotation. Remember, the worst case turning time is when the servo is at the minimum rotation angle and is then commanded to go to maximum rotation angle, all while under load. This can take several seconds on a very high torque servo.

Torque is the tendency of a force to rotate an object about an axis. The torque unit is ounce-inches (oz-in) or kilogram-centimetre (kg-cm). It tell you know about this servo motor can drive a load weight in 1 oz. to move 1 inche or 1kg. weight to moved 1 centimeter (1oz. = 0.028kg. or 1kg. = 25.274oz.). Normally the RC servo motor has 3.40 kgcm/47oz-in torque.

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1 to 2 millsecond pulse

(a) Servo motor control pulse 20ms period

1 millisecond pulse

(b) 1 millisecond pulse causes servo horn moves anti-clockwise direction to last right position (0o)

STANDARD SERVO MOTOR

1.5 millisecond pulse

(c) 1.5 millisecond pulse causes servo horn moves to center position

STANDARD SERVO MOTOR

2 millisecond pulse

(d) 2 millisecond pulse causes servo horn moves clockwise direction to last left position (180o)

STANDARD SERVO MOTOR

Figure 10-4 : Timing diagram of the servo motor control pulse

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10.3 Servo motor control management of AT-BOT robot In an AT-BOT robot, using the port pins 8 to 13 (sorted by the requirements of Wiring I/O and required to use these pin names in the programming in Wiring IDE) to generate pulse signal in order to drive servo motors.

41 ADC1

40 ADC0

46 ADC6

45 ADC5

44 ADC4

5

42 ADC2

4

43 ADC3

START

The power supply voltage of servo motors comes from a battery connected with the circuit board of ATX through the control circuit of the constant power supply. At +6V can supply the electric current 1500mA, so it can be applied to all models of small servo motors, which use the power supply in the range of 4.8 to 6V.

C r e a t o r e > >> > > > > > 3

c o n t r o l l er R b o a r d USB DATA

2

ON TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

1

E2

KNOB

ADC7

SW1

49

SW2

50

48

SERVO PORT 9

BATTERY LEVEL

10 11 12 13 S

8

+

-

7.2-9V BATT.

0

RESET

14

PC6

15 PC7

MOTOR

6 of Servo motor output [8 to 13]

Figure 10-5 : Demonstration of servo motor outputs of the AT-BOT

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10.4 Servo motor library One important thing of controlling servo motors is to create pulse signal, which comes from programming to command the microcontroller to produce desirable pulse signal. To help the programming controlled by C language in AT-BOT robots more convenient, the library file servo.h has to be attached with the program.

This library file supports all functions for controlling 6 servo motor outputs of the ATX controller board. This library must be included at the top of the program with the command #include as follows : #include <servo.h> or #inclue <atx.h> There is one function. It is servo.

Syntax void servo(unsigned char _ch, int _pos)

Parameter _ch - Servo motor output (8 to 13) Define as 8 for servo motor output #1 (8) Define as 9 for servo motor output #2 (9) Define as 10 for servo motor output #3 (10) Define as 11 for servo motor output #4 (11) Define as 12 for servo motor output #5 (12) Define as 13 for servo motor output #6 (13) _pos - Set the sevo motor shaft poistion (0 to 180 and -1) If set to -1, disable selected servo motor output

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Experiment 23 AT-BOT controlled the servo motor In this experiment presents about how to test the positional control of the servo motorat ch. 10 of an AT-BOT by pressing the SW1 (adding a positional value) and SW2 (reducing a position value) swithes as well as monitoring a value of the reference position of the servo motor. The reference position value will be shown at the LCD module on the AT-BOT robot.

Additional hardware connection  Connect a servo motor to port 10 of servo motor output of the AT-BOT

Procedure L23.1 Create the new sketch file. Type the Listing L23-1 and save as servo_test.pde L23.2 Compile and upload the sketch to the AT-BOT. Unplug the USB cable.

L23.3 Run the program.

AT-BOT display shows the title message :

Position: xx

41 ADC1

40 ADC0

46 ADC6

45 ADC5

44 ADC4

5

42 ADC2

4

43 ADC3

START

therefore xx is the servo motor shaft’s position number

3

Pos ition: >20> > >> con troll er R boa rd

Servo motor

Decrease position

USB DATA

2

ON TWI UART1 0 SCL 1 SDA 2 RX1 3 TX1

KNOB

ADC7

SW1

49

SW2

50

48

SERVO PORT 8

9

BATTERY LEVEL

10 11 12 13 S

7.2-9V BATT.

0

RESET

1

Increase position

+

-

E2

14

PC6

15 PC7

MOTOR

STANDARD SERVO MOTOR

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L23.4 Try to press the SW1 switch on the AT-BOT to increase the postion value.

The servo motor shaft is driven to upper position. Also at the display of AT-BOT shows the position value. However if the value is greater than 90 greatly, tthe servo motor may not stable to maintain position.

L23 .5 Press the SW2 switch on the AT-BOT to decrease the postion value.

The servo motor shaft is driven to lower position. At the display of AT-BOT shows the position value. However if the value is less than 20 greatly, the servo motor may not stable to maintain position also.

Note: About the positional range of servo motors, each manufacturer may have different positional range or direction of position. Therefore, developers have to create programming about testing positional values of servo motors in order to know how many a positional value is in the control program when you need to control a servo motor to be located at a desired position. #include <atx.h> unsigned int pos=0; void setup() {} void loop() { lcd(“Position: %d servo(10,pos); if(sw1()==0) { pos++; sleep(100); } if(sw2()==0) { pos - - ; sleep(100); } }

// Include the main library // Declare the servo motor position variable

“,pos);

// Show the position value // Set the postion to servo motor output #10 // Check the SW1 pressing // Increase the position value // Debouncing delay // Check the SW2 pressing // Decrese the position value // Debouncing delay

Code explanation The program will operate in the loop function to repeat showing the result of the positional values of the servo motor at port 10 of AT-BOT and define the values constantly. At the same time, the function will verify addition and deduction of the positional values of servo motor shaft form pressing the switches SW1 and SW2 respectively. The program will work like this repeatedly and continuously.

Listing L23-1 : servo_test.pde, the sketch file for controlling the servo motor shaft position of the AT-BOT