#define trigPin 9
#define echoPin 10
#define ledMerah 2
#define ledHijau 3

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(ledMerah, OUTPUT);
  pinMode(ledHijau, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  long duration, distance;

  // Memicu sensor ultrasonic
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Membaca jarak
  duration = pulseIn(echoPin, HIGH);
  distance = duration * 0.034 / 2;

  // Menyalakan LED berdasarkan jarak
  if (distance <= 5) {
    digitalWrite(ledMerah, HIGH);
    digitalWrite(ledHijau, LOW);
  } else {
    digitalWrite(ledMerah, LOW);
    digitalWrite(ledHijau, HIGH);
  }

  // Menampilkan jarak di Serial Monitor
  Serial.print("Jarak: ");
  Serial.print(distance);
  Serial.println(" cm");

  delay(500);
}