Slave

#include <Wire.h>

int LED = 13;

int x = 0;

void setup() {
  // put your setup code here, to run once:
pinMode (LED, OUTPUT);
Wire.begin(4);
Wire.onReceive(receiveEvent);

}

void receiveEvent(int bytes){
  x = Wire.read();
}

void loop() {
  // put your main code here, to run repeatedly:
if (x == 0) {
  digitalWrite(LED, HIGH);
  delay(540);
  digitalWrite(LED, LOW);
  delay(540);
}
if (x == 3){
  digitalWrite(LED, HIGH);
  delay(200);
  digitalWrite(LED, LOW);
  delay(200);
  }
}