int redLedPin = 9; // Pin LED merah
int yellowLedPin = 10; // Pin LED kuning

void setup() {
  pinMode(redLedPin, OUTPUT);
  pinMode(yellowLedPin, OUTPUT);
}

void loop() {
  // menyalakan lampu merah, meredupkan lampu kuning
  analogWrite(redLedPin, 255); // lampu merah hidup (PWM 100%)
  analogWrite(yellowLedPin, 10); // lampu kuning redup (PWM 10%)
  delay(3000);

  // Nyala lampu kuning, meredupkan lampu merah
  analogWrite(redLedPin, 10); // lampu merah redup (PWM 10%)
  analogWrite(yellowLedPin, 255); // lampu kuning hidup (PWM 100%)
  delay(3000);
}