#include <Wire.h>
void setup()
{
  // set this MC as slave, address 0x1E
  Wire.begin(0x1E);
  // Register a function to be called
  // when a master requests data from this slave device.
  Wire.onRequest(send_count);
}
 
byte count = 0;
 
void loop()
{
    delay(500);
}
 
void send_count()
{
    Wire.write(count);
    count++;
}