#include <TwoWire.h> 
 
void setup() 
{ 
  Wire.begin(); // join i2c bus (address optional for master) 
} 
 
byte x = 0; 
 
void loop() 
{ 
  Wire.beginTransmission(4); // transmit to device #4 
  Wire.send("x is ");        // sends five bytes 
  Wire.send(x);              // sends one byte  
  Wire.endTransmission();    // stop transmitting 
 
  x++; 
  delay(500); 
}