Project 1 - Interfacing a 16*2 LCD with Arduino using I2C protocol

Aim:implementing the Code for “Interfacing a 16*2 LCD with two Arduino’s

code:

master:

/* Arduino Uno R3 #2 */
/* The master initiates all communication on the I2C bus and supplies the clock for all slave devices. The I2C component supports standard clock speeds up to 1000 kbps. The I2C component is compatible with other third-party slave and master devices. */

//I2C MASTER CODE
//I2C Communication between Two Arduino

#include<Wire.h> //Library for I2C Communication functions
#include<LiquidCrystal.h> //Library for LCD display function
LiquidCrystal lcd(12,11,5,4,3,2); //Define LCD Module Pins (RS,EN,D4,D5,D6,D7)

void setup()

{
lcd.begin(16,2); //Initilize LCD display
lcd.setCursor(0,0); //Sets Cursor at first line of Display
lcd.print("Master Circuit"); //Prints CIRCUIT DIGEST in LCD
lcd.setCursor(0,1); //Sets Cursor at second line of Display
lcd.print("Arduino #2 I2C"); //Prints I2C ARDUINO in LCD
delay(5000); //Delay for 5 seconds
lcd.clear(); //Clears LCD display
Serial.begin(9600); //Begins Serial Communication at 9600 baud rate
Wire.begin(); //Begins I2C communication at pin (A4,A5)
}

void loop()

{
Wire.requestFrom(8,1); // request 1 byte from slave arduino (8)
byte MasterReceive = Wire.read(); // receive a byte from the slave arduino and store in MasterReceive
int potvalue = analogRead(A0); // Reads analog value from POT (0-5V)
byte MasterSend = map(potvalue,0,1023,0,127); //Convert digital value (0 to 1023) to (0 to 127)

Wire.beginTransmission(8); // start transmit to slave arduino (8)
Wire.write(MasterSend); // sends one byte converted POT value to slave
Wire.endTransmission(); // stop transmitting
lcd.setCursor(0,0); //Sets Currsor at line one of LCD
lcd.print(">> Master <<"); //Prints >> Master << at LCD
lcd.setCursor(0,1); //Sets Cursor at line two of LCD
lcd.print("Slave Value:"); //Prints SlaveVal: in LCD
lcd.print(MasterReceive); //Prints MasterReceive in LCD received from Slave
//lcd.print(analogRead(A0));
Serial.println("Master Received From Slave:"); //Prints in Serial Monitor
Serial.println(MasterReceive);
delay(500);
lcd.clear();

}

slave:

/* Arduino Uno R3 #1 */
/* The slaves are the devices that respond to the master. A slave cannot initiate a transfer over the I2C bus, only a master can do that. There can be, and usually are, multiple slaves on the I2C bus, however there is normally only one master. */

//I2C SLAVE CODE
//I2C Communication between Two Arduino

#include<Wire.h> //Library for I2C Communication functions
#include<LiquidCrystal.h> //Library for LCD display function
LiquidCrystal lcd(12,11,5,4,3,2); //Define LCD Module Pins (RS,EN,D4,D5,D6,D7)

byte SlaveReceived = 0;

void receiveEvent (int howMany) //This Function is called when Slave receives value from master
{
SlaveReceived = Wire.read(); //Used to read value received from master and store in variable SlaveReceived
}

void requestEvent() //This Function is called when Master wants value from slave
{
int potvalue = analogRead(A0); // Reads analog value from POT (0-5V)
byte SlaveSend = map(potvalue,0,1023,0,127); // Convert potvalue digital value (0 to 1023) to (0 to 127)
Wire.write(SlaveSend); // sends one byte converted POT value to master
}

void setup()

{
lcd.begin(16,2); //Initilize LCD display
lcd.setCursor(0,0); //Sets Cursor at first line of Display
lcd.print("Slave Circuit"); //Prints CIRCUIT DIGEST in LCD
lcd.setCursor(0,1); //Sets Cursor at second line of Display
lcd.print("Arduino #1 I2C"); //Prints I2C ARDUINO in LCD
delay(5000); //Delay for 5 seconds
lcd.clear(); //Clears LCD display
Serial.begin(9600); //Begins Serial Communication at 9600 baud rate
Wire.begin(8); //Begins I2C communication with Slave Address as 8 at pin (A4,A5)
Wire.onReceive(receiveEvent); //Function call when Slave receives value from master
Wire.onRequest(requestEvent); //Function call when Master request value from Slave
}

void loop(void)
{
lcd.setCursor(0,0); //Sets Currsor at line one of LCD
lcd.print(">> Slave <<"); //Prints >> Slave << at LCD
lcd.setCursor(0,1); //Sets Cursor at line two of LCD
lcd.print("Master Value:"); //Prints MasterVal: in LCD
lcd.print(SlaveReceived); //Prints SlaveReceived value in LCD received from Master
Serial.println("Slave Received From Master:"); //Prints in Serial Monitor
Serial.println(SlaveReceived);
delay(500);
lcd.clear();

}