Networking of Multiple Microcontrollers
Networking of Multiple Microcontrollers Introduction ďƒ˜ The project is designed to demonstrate how multiple microcontrollers can be connected in a network to achieve the desired output. More and more microcontrollers are embedded in different kinds of products from industrial environment to domestic area; a good example is the automobile sector. A modern day car has number of microcontrollers integrated within its system.
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Networking of Multiple Microcontrollers Block Diagram
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Networking of Multiple Microcontrollers Hardware Requirements
8051 series Microcontrollers Keypad LCD Relay Transformer Diodes LED Resistors Capacitors Regulator Buzzer Lamp http://www.edgefxkits.com/
Networking of Multiple Microcontrollers Software Requirements Keil compiler Language: Embedded C or Assembly
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Networking of Multiple Microcontrollers Communications and Networks Data Communications • Transmission of signals • Encoding, interfacing, signal integrity, multiplexing etc. Networking • Topology & architecture used to interconnect devices
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Networking of Multiple Microcontrollers Network Trends Voice, Image, Data, Video
Microcontroller Microcontroller
Networking
Wireless Integrated Systems! http://www.edgefxkits.com/
Networking of Multiple Microcontrollers Communication Systems Process describing transfer of information, data, instructions between one or more systems through some media. Examples: • People, computers, cell phones, etc. • Computer communication systems Receivers and transmitters: Desktop computers, mainframe computers, etc.
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Networking of Multiple Microcontrollers Communication Systems Signals passing through the communication channel can be Digital, or analog. • Analog signals: continuous electrical waves. • Digital signals: individual electrical pulses (bits) Communication channel
RX
TX
RX RX
Amp/Adaptor
Communication media
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Networking of Multiple Microcontrollers Working Principle ďƒ˜ The networking and communication between them becomes necessary. ďƒ˜ The importance of having multiple microcontrollers against a single one is if one of the microcontrollers goes bad only the function related to that particular microcontroller will be affected.
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Networking of Multiple Microcontrollers Working Principle The project demonstrates a command based monitoring tool using the RS232 protocol. A network of three microcontrollers is used in this project. The first one is connected to a keypad for input action. The second one is connected to an LCD display and the third one to drive a relay for controlling any load (LAMP).
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Networking of Multiple Microcontrollers Working Principle Input takes a password on the first MC to display it on the second MC while the third one executes the output only if the password is right. Wrong password if entered will generate a buzzer sound. Though this task can be performed by a single microcontroller. The project uses multiple microcontrollers to explain the concept of networking.
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Networking of Multiple Microcontrollers Working Principle It is practically impossible by a single microcontroller to handle input action, display and output which are located way apart. The system uses a combination of three microcontrollers for this purpose. • One is used to operate the load. •
second one is used to display output on LCD display .
• The third one is used to take user input through a keypad.
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Networking of Multiple Microcontrollers Working Principle Consider a situation which requires 15 connections for a display unit from microcontroller, and 7 connections from keypad. So instead of using single microprocessor and multicore cables for kilometers. We use a single cable and more microcontrollers to simplify the working and reduce costs.
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Networking of Multiple Microcontrollers MICROCONTROLLER It is a smaller computer Has on-chip RAM, ROM, I/O ports. etc..
CPU
I/O Port
RAM ROM Serial Timer COM Port
A single chip Microcontroller
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Networking of Multiple Microcontrollers INTERNAL STRUCTURE OF A MICRO CONTROLLER
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Networking of Multiple Microcontrollers Multi Microcontroller Networking System ďƒ˜ Our system aims at connecting and coordinating multiple microcontrollers in order to achieve the desired output. ďƒ˜ Increasing number of microcontrollers are used these days for various industrial and domestic applications.
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Networking of Multiple Microcontrollers Designing The Communications Microcontroller Microcontrollers • Main Microcontroller: i.MX31 from Freescale • Communications Microcontroller: LPC2194/01 from NXP • Low Level Microcontroller: LPC2194/01 from NXP
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Networking of Multiple Microcontrollers Communication Protocols • Main to Communications Full Speed USB • Communications to Low Level CAN Bus
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Networking of Multiple Microcontrollers Power Supply A DC Power Supply Unit (commonly called a PSU) deriving power from the AC mains (line) supply performs a number of tasks: •
It changes (in most cases reduces) the level of supply to a value suitable for driving the load circuit.
•
It produces a DC supply from the mains (or line) supply AC sine wave.
•
It prevents any AC from appearing at the supply output.
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Networking of Multiple Microcontrollers Parts of a Power Supply The output voltage is kept at a constant level, independent of changes in: •
The AC supply voltage at the supply input.
•
The Load current drawn from the supply output.
•
Temperature.
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Networking of Multiple Microcontrollers Power Supply
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Networking of Multiple Microcontrollers Relay It is a electro magnetic switch. Used to control the electrical devices. Copper core magnetic flux plays main role here.
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Networking of Multiple Microcontrollers Relay The relay's switch connections are usually labeled COM, NC and NO: COM = Common, always connect to this; it is the moving part of the itch. NC = Normally Closed, COM is connected to this when the relay coil is off. NO = Normally Open, COM is connected to this when the relay coil is on .
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Networking of Multiple Microcontrollers BC547 (NPN –Transistor) The BC547 transistor is an NPN Epitaxial Silicon Transistor. It is used in general-purpose switching and amplification BC847/BC547 series 45 V, 100 mA NPN general-purpose transistors.
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Networking of Multiple Microcontrollers BC547 (NPN –Transistor) The ratio of two currents (Ic/Ib) is called the DC Current Gain of the device and is given the symbol of hfe or nowadays Beta, (β).
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Networking of Multiple Microcontrollers BC547 (NPN –Transistor) The current gain from the emitter to the collector terminal, Ic/Ie, is called Alpha, (α), and is a function of the transistor itself.
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Networking of Multiple Microcontrollers Liquid Crystal Display (LCD) Most common LCDs connected to the microcontrollers are 16x2 and 20x2 displays. This means 16 characters per line by 2 lines and 20 characters per line by 2 lines, respectively. The standard is referred to as HD44780U. It refers to the controller chip which receives data from an external source (and communicates directly with the LCD.
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Networking of Multiple Microcontrollers Liquid Crystal Display (LCD) ďƒ˜ If an 8-bit data bus is used the LCD will require 11 data lines (3 control lines plus the 8 lines for the data bus). ďƒ˜ The three control lines are referred to as EN, RS, and RW.
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Networking of Multiple Microcontrollers Liquid Crystal Display (LCD) Diagram
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Networking of Multiple Microcontrollers Application ďƒ˜ This technology is widely used in modern automobiles.
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Networking of Multiple Microcontrollers Future Enhancement ďƒ˜ This project being based on serial communication can be enhanced by using wireless communication among the controllers by avoiding costly cabling.
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Networking of Multiple Microcontrollers Conclusion ďƒ˜ We have learned how multiple microcontrollers can be connected in a simple networking system to get the desired output. These type of networking of multiple microcontrollers are used in many areas like industrial and domestic areas.
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