int lampu1 = 13;
int lampu2 = 7;
void setup() {
  Serial.begin(9600);
  pinMode(lampu1, OUTPUT);
  pinMode(lampu2, OUTPUT);
}

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

  digitalWrite(lampu2, HIGH);
  delay(500);
  digitalWrite(lampu, LOW);
  delay(500);
}