14. Networking and communications

Individual Assignment:

Design, build, and connect wired or wireless node(s) with network or bus addresses.

Group Assignment:

Send a message between two projects.

please check the group assignment here.

For this assignment we are required to make a network using the Arduino Uno boards and connecting them together.

There are 3 ways you can make a network using the board.

1- Serial Networking

2- SPI Networking

3- I2C Networking

I picked the I2C circuit since it is requires only few wires to connect them to the board unlike the other networking methods.

I connected the wires using a solider to the Arduino Uno board. The connectors are connected to the VCC and Ground ports on the board and they function as the Master and Slave.-

I made this support stand for the two Arduino boards that I will use for my assignment. They will act as a support for the Master and Slave boards.

As shown in the picture the connectors of the board are as follows:

SDA: Green

SCL: Yellow

VCC : Red

and Ground : Black

I connected the wires of both of the board to a single battery to make it easier instead of using two batteries for each board.

Master Code

#include <Wire.h> //add the library for communication

void setup()
{
  Wire.begin(); // start the communiction
}

void loop()
{
  Wire.beginTransmission(1); // start transmitting to device 1
  Wire.write('H'); // send the letter "H" on the transmission line
  Wire.endTransmission(); //end the transmission

  delay(500);// delay for half a second

  Wire.beginTransmission(1); // transmit to device
  Wire.write('L');  // send the letter "L"
  Wire.endTransmission();  // end transmission

  delay(500); //wait for 0.5 sec.

  Wire.beginTransmission(2); //start transmission to device 2
  Wire.write('H'); //send "H"
  Wire.endTransmission(); //end transmission

  delay(500);  //wait for 0.5 sec

  Wire.beginTransmission(2); //start transmitting to device 2
  Wire.write('L');   // send "L"
  Wire.endTransmission();

  delay(500);  //delay for 0.5 sec
}

Slave Code

#include <Wire.h> //add the library for communication
const byte slaveId = 1;// set this device as slave 1

void setup()
{
  Wire.begin(slaveId);// begin transmission for slave 1
  Wire.onReceive(receiveEvent);//register event

  pinMode(13,OUTPUT);//set pin 13 as output
  digitalWrite(13,LOW);// set pin 13 as low or 0
}
void loop()
{
}
void receiveEvent(int howMany)
{
  char inChar;// set a variable in characters
  while(Wire.available() > 0)//check if the transmission is available
  {
    inChar = Wire.read(); //read the data in the transmission line
    if (inChar == 'H') // check if the data is the letter "H"
    {
      digitalWrite(13, HIGH);// then digital write pin 13  as HIGH
    }
    else if (inChar == 'L')// if the data is "L"
    {
      digitalWrite(13, LOW);// then write pin 13 as LOW
    }
  }
}

Demonstration video

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