// BOARD 3

#include <Wire.h>

unsigned int addressReceiver = 3;

int ledPin = 8;

byte rcvData;

void setup() {
  Wire.begin(addressReceiver); // On the 3rd board
  Wire.onReceive(receiveEvent);
  pinMode(ledPin, OUTPUT);

  rcvData = 0;
}

void loop() {
  
  if (rcvData == 0)
    digitalWrite(ledPin, LOW);
  else if (rcvData == 1)
    digitalWrite(ledPin, HIGH);
}

void receiveEvent(int howMany){
  rcvData = Wire.read();
}