#include <Wire.h>

const int buttonPin = 2;     // the number of the pushbutton pin

void setup() {
  Wire.begin(); // join i2c bus (address optional for master)
  pinMode(buttonPin, INPUT);
  digitalWrite(buttonPin,HIGH);
}

void loop() {
  if(digitalRead(buttonPin) == 1){
    //For slave 1
    Wire.beginTransmission(8); // transmit to device #8
    Wire.write(1);              // sends one byte
    Wire.endTransmission();    // stop transmitting
    
    //For slave 2
    Wire.beginTransmission(6); // transmit to device #6
    Wire.write(2);              // sends one byte
    Wire.endTransmission(); 
  } else if(digitalRead(buttonPin) == 0){
    //For slave 1
    Wire.beginTransmission(8); // transmit to device #8
    Wire.write(2);              // sends one byte
    Wire.endTransmission();    // stop transmitting
    
    //For slave 2
    Wire.beginTransmission(6); // transmit to device #6
    Wire.write(1);              // sends one byte
    Wire.endTransmission(); 
  }
  delay(100);
}