int lampu1 = 7;
  int lampu2 = 13;

void setup() {
  pinMode(lampu1, OUTPUT);
  pinMode(lampu2, OUTPUT);
}

void loop() {
  digitalWrite(lampu1, HIGH);
  delay(500);
  digitalWrite(lampu1, LOW);
  delay(500);
  digitalWrite(lampu2, HIGH);
  delay(500);
  digitalWrite(lampu2, LOW);
  delay(500);
}