KNX mockup

KNX EDUCATION MOCKUP

PCB DESIGN

Designed by:

Kkalil Jarray

Wajdi Abbassi

Tasked by:

Mr Oussama Feki

BRIEF

DESCRIPTION OF KNX mockups

KNX is a standard for home and building control that uses a single wired control bus to connect sensors, actuators, and controllers in a building automation system

KNX education mockup boards are typically used in educational settings to teach students about the KNX standard and how it is used in building automation systems These mockup boards typically include sensors, actuators, and a control unit, and allow students to experiment with different configurations and control strategies They can also be used for training professionals in the field of building automation

DESIGN DRAWBACKS

There are a few potential disadvantages to using KNX education mockup boards, including:

Cost: These mockup boards can be expensive, especially if they include a wide range of sensors, actuators, and controllers

Limited functionality: These mockup boards may not have all the functionality of a real-world building automation system, which could limit the educational value for students

Limited scalability: The mockup boards may only allow for a limited number of devices to be connected, which could limit the range of scenarios that students can experiment with

Limited to certain technology : The mockup boards may be limited to a specific technology, which may not be the most widely used in the industry

Maintenance: These mockup boards can require regular maintenance to ensure they are functioning properly, which can be time-consuming and costly

Less realistic: As these are mockups, the boards can be less realistic to the real world scenarios

PROPOSED SOLUTION

One solution could be to supplement the use of KNX education mockup boards with virtual simulation software This would allow students to experiment with more complex scenarios and control strategies, while still learning the basics of the KNX standard

To overcome the limitation of the scalability, you could use a modular design for the mockup boards, which would allow students to easily add or remove devices as needed

CONCEPT OVERVIEW

IN-DEPTH ANALYSIS

Data acquisition :

the HLW8012 module It is a low power consumption, high precision energy measurement IC that can can be used to measure the current, voltage, and power consumption of a device by using a current transformer and a voltage divider circuit, which then sends the measurement data to a microcontroller or other device for processing

It is a low cost and easy to use solution for measuring power consumption and it has a good accuracy, it is widely used in the industry

Power consumption data distribution

DUAL 4-CHANNEL ANALOG MULTIPLEXER/DEMULTI PLEXER

The MC74HC4052ADG It is a Dual 4-Channel Analog Multiplexer/Demultiplexer IC made by ON Semiconductor It is a CMOS analog switch that allows to route two signals out of four possible inputs to a single output It is controlled by two digital select inputs (S0, S1) It can be used to multiplex two analog signals into one output, or to demultiplex a single input into two outputs This device is useful in electronic circuits where analog signals need to be routed in different ways based on digital control signals It has high input impedance and low on resistance which makes it ideal for signal routing in low power consumption applications

MOD 2 COUNTER USING D FLIP FLOP

A Mod 2 counter using D flip-flops is a type of digital counter circuit that counts in binary, it counts up to a maximum value of "10" in binary or "2" in decimal before resetting back to "00" or "0". It is also known as a binary counter or a 2-bit counter. It uses D flip-flops as the building blocks of the counter circuit.

SYSTEM OPERATION PROCESS :

A Mod 2 counter using D flip-flops combined with the MC74HC4052ADG module can be used to achieve signal multiplexing to a microcontroller Here's how it works:

The Mod 2 counter is used to generate a series of digital signals that are used to control the MC74HC4052ADG module The counter is configured to count from 0 to 1 and then reset back to 0

The output of the counter is connected to the select inputs (S0, S1) of the MC74HC4052ADG module The output of the counter is used to select which of the four inputs of the module is connected to the output

The four analog signals to be multiplexed are connected to the four inputs of the MC74HC4052ADG module

The output of the MC74HC4052ADG module is connected to the microcontroller's analog-todigital converter (ADC) input

The microcontroller continuously reads the ADC input, which will be one of the four multiplexed signals depending on the state of the counter output

As the counter counts from 0 to 1, the select inputs of the MC74HC4052ADG module change state, connecting the output to a different input signal This causes the output of the module to switch between the four input signals at a rate determined by the counter's clock

The microcontroller can keep track of the state of the counter and determine which input signal is currently being sent to the ADC input

By using this method, it's possible to multiplex multiple analog signals into a single input, allowing the microcontroller to read multiple signals sequentially without requiring multiple ADC inputs This can be useful in applications where there is a limited number of ADC inputs available on the microcontroller, such is the case for the arduino nano

VOLTAGE TRANSFORMERS

Design principles

Simulation results.

Steps

Connect the input pin of the LM317 to a voltage source greater than 6V, for example, a 15V DC power supply.

Connect the output pin of the LM317 to the load that needs a 6V power supply

Create a voltage divider circuit by connecting two resistors in series between the adjust pin of the LM317 and ground

Select the values of the resistors in the voltage divider circuit such that the output voltage of the LM317 is 6V The formula to calculate the output voltage is: Vout = 1 25 (1 + (R2/R1))

Connect the first resistor (R1) between the adjust pin and the output pin

Connect the second resistor (R2) between the adjust pin and ground

Turn on the input voltage source and check the output voltage at the output pin of the LM317 It should be around 6V

Adjust the values of the resistors in the voltage divider circuit if necessary to fine-tune the output voltage to 6V

Once the output voltage is stable and at 6V, the circuit is ready to use and provide a stable power supply to the connected load

DESIGN PRINCIPLES

The LM317 is a voltage regulator IC that can be used to create a stable voltage supply It can output a fixed voltage between 1 2V and 37V, with a maximum current of 1 5A It has three pins: the input pin, the output pin, and the adjust pin The input pin is connected to the input voltage source, the output pin is connected to the load, and the adjust pin is used to set the output voltage The output voltage is set by connecting a resistor between the adjust pin and the output pin, and a second resistor between the adjust pin and ground By selecting the values of these resistors, the output voltage can be set to a specific value within the range of the IC

VOLTAGE TRANSFORMERS

Design principles

Simulation results.

SIMULATION RESULTS.

-Stable voltage across load

-Insignificant current draw

SPI (Serial Peripheral Interface) is a communication protocol that allows multiple devices to communicate with each other over a shared bus To establish SPI communication between a Raspberry Pi 3 (RPi3) and an Arduino Nano, the following steps can be taken:

MOSI (Master Out, Slave In) : This pin is used to send data from the RPi3 (the master) to the Arduino Nano (the slave). The RPi3's MOSI pin should be connected to the Arduino Nano's MOSI pin.

MISO (Master In, Slave Out) : This pin is used to send data from the Arduino Nano (the slave) to the RPi3 (the master) The RPi3's MISO pin should be connected to the Arduino Nano's MISO pin SCLK (Serial Clock) : This pin is used to synchronize the data transfer between the RPi3 and the Arduino Nano The RPi3's SCLK pin should be connected to the Arduino Nano's SCLK pin

GND : This pin is used to provide a common reference voltage between the RPi3 and the Arduino Nano The RPi3's GND pin should be connected to the Arduino Nano's GND pin

Explaining the importance of a level shifter :

A level shifter is an electronic circuit that is used to translate the voltage level of a signal from one voltage range to another voltage range This is important in situations where the devices that are communicating have different voltage levels

In the case of establishing SPI communication between a Raspberry Pi 3 (RPi3) and an Arduino Nano, the RPi3 operates at 3 3V while the Arduino Nano operates at 5V Connecting the two devices directly can cause damage to the RPi3 because its input pins are not designed to handle 5V A level shifter is used to translate the 5V signals from the Arduino Nano to 3 3V signals that can be safely received by the RPi3

One way to make a level shifter is to use a BSS138TA-VB MOSFET transistor The BSS138TA-VB is a N-channel enhancement mode MOSFET that can be used as a level shifter The circuit is simple, it consists of connecting the BSS138TA-VB to the RPi3 and the Arduino Nano, in a configuration known as a "high-side switch"

Connect the gate of the BSS138TA-VB to the RPi3's output pin (3 3V)

Connect the source of the BSS138TA-VB to the GND

Connect the drain of the BSS138TA-VB to the input pin of the Arduino Nano (5V)

When the RPi3 output pin is high (3 3V), the BSS138TAVB MOSFET will conduct and the voltage at the drain will be equal to the voltage at the source, allowing the communication

It's important to note that the BSS138TA-VB is a bidirectional level shifter, it means that it allows communication in both directions, but it's important to consider the current capabilities of the MOSFET, and if needed, add a current-limiting circuit to protect the devices.

OPTO-COUPLER BASED CIRCUIT FOR KNX MODULE DATA AQUISITION :

Opto-couplers are devices that use an optical interface to isolate the electrical signals between two circuits The K10101C, also known as the PC817C, is a type of opto-coupler that uses an infrared LED and a phototransistor to provide electrical isolation Using an opto-coupler in a circuit can help to ensure data acquisition from KNX modules and sending it to a Raspberry Pi 3 by providing galvanic isolation between the two devices

To use the K10101C (PC817C) opto-coupler in a circuit for data acquisition from KNX modules and sending it to a Raspberry Pi 3, the following steps can be taken:

Connect the KNX module to the opto-coupler: Connect the data output of the KNX module to the input pin of the optocoupler The input pin of the opto-coupler is the pin that is connected to the infrared LED Connect the Raspberry Pi 3 to the opto-coupler: Connect the data input of the Raspberry Pi 3 to the output pin of the optocoupler The output pin of the opto-coupler is the pin that is connected to the phototransistor. Power the opto-coupler: Connect the power supply to the opto-coupler. The K10101C (PC817C) opto-coupler requires a forward current of at least 5mA to the infrared LED to operate correctly.

Configure the Raspberry Pi 3 to receive data: On the Raspberry Pi 3, use a programming language such as Python to configure the input pin as a digital input and to receive data from the opto-coupler Send data from the KNX module: The KNX module will send data through the optocoupler's input pin and the infrared LED will emit light which is received by the phototransistor on the other side of the opto-coupler. The phototransistor will then convert the light into an electrical signal and send it to the Raspberry Pi 3's input pin. Receive data on the Raspberry Pi 3: The Raspberry Pi 3 will receive the data from the optocoupler and process it according to the program running on it

By using the K10101C (PC817C) opto-coupler, the data transfer between the KNX module and the Raspberry Pi 3 is isolated from each other, preventing interference and ensuring a reliable data transfer

3.

PCB ROUTING

Power PCB Control PCB

POWER PCB

Heat dissipation

Measures reliability

Electrical Hazard

PCB ROUTING

Power PCB

Control PCB

CONTROL PCB

Electromagnetic compatibility

Delay

Measures reliability