#define TRIG_PIN 3  // Ganti pin untuk TRIG
#define ECHO_PIN 4  // Ganti pin untuk ECHO
#define LED_PIN 13

void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(LED_PIN, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  // Mengirimkan sinyal trigger
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  // Membaca sinyal echo
  long duration = pulseIn(ECHO_PIN, HIGH);
  // Menghitung jarak (cm)
  float distance = (duration * 0.034) / 2;

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

  // Menyalakan LED jika jarak kurang dari 20 cm
  if (distance < 20) {
    digitalWrite(LED_PIN, HIGH);
  } else {
    digitalWrite(LED_PIN, LOW);
  }

  delay(100);
}