#include <Wire.h>
#define LedPin 13 

void setup()
{
  Wire.begin(4);                	// join i2c bus with address 4
  Wire.onReceive(receiveEvent); 	// register event
  Serial.begin(9600); 				// start serial for output
  pinMode(LedPin, OUTPUT);			// initialize LEDpin as an output
}

void loop()
{
  digitalWrite(LedPin, HIGH);   	// turn the LED on by making the voltage HIGH
  delay(1000);                      // wait for a second
  digitalWrite(LedPin, LOW);    	// turn the LED off by making the voltage LOW
  delay(1000);                      // wait for a second
}

                                    
                                    
void receiveEvent(int howMany)		// function that is registered as an event whenever data is received from master
{
  while(1 < Wire.available()) 		// loop through all but the last
  {
    char c = Wire.read(); 			// receive byte as a character
    Serial.print(c);         		// print the character
  }
  int x = Wire.read();    			// receive byte as an integer
  Serial.println(x);         		// print the integer
}