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

//master code

/*
LiquidCrystal Library - Hello World

Demonstrates the use a 16x2 LCD display. The LiquidCrystal
library works with all LCD displays that are compatible with the
Hitachi HD44780 driver. There are many of them out there, and you
can usually tell them by the 16-pin interface.

This sketch prints "Hello World!" to the LCD
and shows the time.

The circuit:
* LCD RS pin to digital pin 12
* LCD Enable pin to digital pin 11
* LCD D4 pin to digital pin 5
* LCD D5 pin to digital pin 4
* LCD D6 pin to digital pin 3
* LCD D7 pin to digital pin 2
* LCD R/W pin to ground
* LCD VSS pin to ground
* LCD VCC pin to 5V
* 10K resistor:
* ends to +5V and ground
* wiper to LCD VO pin (pin 3)

Library originally added 18 Apr 2008
by David A. Mellis
library modified 5 Jul 2009
by Limor Fried (http://www.ladyada.net)
example added 9 Jul 2009
by Tom Igoe
modified 22 Nov 2010
by Tom Igoe

This example code is in the public domain.

http://www.arduino.cc/en/Tutorial/LiquidCrystal
*/

// include the library code:
#include <LiquidCrystal.h>
#include<Wire.h>
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
char masterReceive[16];

void setup() {
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
lcd.print("I2Ccommunication");// Print a message to the LCD.
Wire.begin();//I2C communication begins here
Serial.begin(9600);//serial communication begins with baud rate
}

void loop() {
// set the cursor to column 0, line 1
// (note: line 1 is the second row, since counting begins with 0):
Wire.requestFrom(8,16);//requesting message from slave
int i=0;
lcd.setCursor(0, 1);//lcd display is set to column 1 and row 0
while(0<Wire.available()){//if data is available it enters the loop
masterReceive[i]=Wire.read();//each character is taken from slave and saved into masterrecevice character array
//data is printed in serial monitor
Serial.print(masterReceive[i]);
Serial.println();
i++;
}
lcd.print(masterReceive);//masterReceive data is printed on the lcd display
Serial.print(masterReceive);//data is printed in serial monitor
delay(500);
Serial.println();
Wire.end();//i2c communication is ended
}

// slave code

// C++ code
//
#include<Wire.h>
void setup()
{
Serial.begin(9600);//serial communication begins with baud rate
Wire.begin(8);//I2C Communication is started with 8 bit address
Wire.onRequest(RequestEvent);//called when master requests data from slave
}

void loop()
{
delay(500);
}
void RequestEvent()
{
char buffer[20];//char array is declared
String message = "Messagefromslave";//message is initialised
message.toCharArray(buffer,20);//string is typecasted to char array
Wire.write(buffer);//data is written to master
}