Week 13: Network and Communication
23rd March - 29th March 2022
Task to be carried out this week
Group Assignment
  1. send a message between two projects
    2. Click for group assignment
Individual Assignment
  1. Design, build, and connect wired or wireless node(s) with network or bus addresses
The softwares used during the week's assignment
  • Arduino IDE: Writing codes for the communication between two boards
  • Visual Studio: For Documentation
Action Plan
Date Work Allocation
16th March Lecture on Network and Communication by Prof. Neil
23rd March lecture on week's assignment by the local instructor(Suhas)
24th March Learning about communication protocols
25th March Board Design and Milling
26th March Soldering
27th March testing communication between the two boards
28th March Documentation
Communication Protocols

Communication protocols are the rules that governs the communication between two electronic devices.Communications protocols can cover authentication, error detection and correction, and signaling. They can also describe the syntax, semantics, and synchronization of analog and digital communications.

Types of Communication Protocol
The communication protocol is broadly divided into two categories namely;

  • Inter System Protocol
  • Intra System Protocol

    • Inter System Protocol
    These protocols are used for communication between two different devices. They are further divided into 3 major categories as follows;

    1. UART Protocol:
      2. UART stands for Universal Asynchronous Transmitter and Receiver. It is a serial communication pf 2 wired protocols where by the data cable signal lines are labeled as RX and TX. The UART takes bytes of data and sends the individual bits in a sequential manner.UART is a half-duplex protocol. Half-duplex means transferring and receiving the data but not at the same time. Examples of UART protocol communication are Emails, SMS and Walkie-talkie.

    2. USART Protocol:
      3. USART stands for a universal synchronous and asynchronous transmitter and receiver. Similar to UART protocol, it is also a serial communication of two wired protocol and the data cables are labeled as Rx and Tx. It is used for transmitting and receiving the data byte by byte along with the clock pulses. However, it is a full duplex protocol meaning it transmits and receives data simultaneously to different board rates. telecommunication is an examples of USART protocol.

    3. USB Protocol:
      4. USB stands for Universal Serial Bus. It is also a serial communication of 2 wired protocols. The data cable signal lines are labeled as D+ and D-. Such protocols are used for communication with system pheripherals meaning it is used for sending and receiving data serially to the host and peripheral devices. USB communication requires driver software that is based on the functionality of the system.USB devices can transfer data on the bus without any request on the host computer. Examples of USB protocols are Mouse, Keyboard, Hubs, switches, pen drive, etc.,.
    Differences between Inter-system Protocols

    Source: https://www.elprocus.com/communication-protocols/

    Intra System Protocols
    The Intra system protocol is used to communicate the two devices within the same circuit board. The use of intra system protocol increases circuit complexity and power consumption but has higher security when transferring data. The intrasystem portocol is divided into 3 major categories namely;

    1. I2C Protocol:
      2. I2C stands for the inter-integrated circuit and it requires only two wires connecting all peripherals to the microcontroller. I2C requires only two wires for connecting all the peripherals to the microcontroller. These active wires, called SDA and SCL, are both bidirectional. SDA line is a serial data line and the SCA line is a serial clock line.

    2. SPI Protocol:
      3. SPI stands for the serial peripheral interface. It is one of the serial communication protocol developed by Motorola. Sometimes SPI protocol is also called a 4-wire protocol. It requires four wires MOSI, MISO, SS, and SCLK. It is a full-duplex communication protocol.

    3. CAN Protocol:
      4. CAN stands for the controller area network. It is a serial communication protocol. It requires two wires CAN High (H+) and CAN low (H-). It was developed by the Robert bosh company in 1985 for in-vehicle networks. It is based on a message-oriented transmission protocol.
    Differences between Inter-system Protocols

    Source: https://www.elprocus.com/communication-protocols/

    Reference: https://www.elprocus.com/communication-protocols/

    Communication between two boards

    For this week's individual assignment I had design, build, and connect wired or wireless node(s) with network or bus addresses. I opted to connect the two boards I designed during my Input and Output week to communicate. For my Input week, I designed a board with LM35 Temperature sensor and for my output week, I used I2C LCD display as my output. This week, my plan is to get the readings of the LM 35 on my input board and get it displayed on the LCD connected to my output board.

    Schematic and Board Design
    Since I used the boards that I made during my input and output week for this week's assignment, I didn't design any new boards. Shown below is the schematic and board diagram of my input board which has LM35 temperature sensor connection. The details of the board design can be found on my input week assignment page


    Similarly, the schematic and board diagram of my output week with I2C LCD connection can be seen below. The details of the board design can be found on my output week assignment page.

    The boards were milled and soldered and the following image shows how the final soldered board.

    Programming the boards

    For programming both my boards, I used my USBTiny/FabISP. Since I had load seperate codes for the two boards, I programmed the boards separately. First, I programmed my Input board which had the LM35 connected to it. The program can be seen below;


    I used the Serial.print command to send the data read from the LM35 to the next board.

    Next, I loaded the output board with the program to get the information to be displayed on the LCD. The program used is as shown below.



    On this program I used the Serial.read command to get the data from the connected board to display on the LCD.

    After programming both the boards, I connected the two boards. The Tx pin on the input board was connected to the Rx pin on output board and the Rx pin on input board was connected to the Tx pin of output board. The power was supplied to the board through the FabISP. The complete connection can be seen below;

    Result: Network and Communication Week
    Project Files