int trig = 9;
int echo = 8;
int relay = 7;
bool ledState = false; // Status awal LED (mati)
bool handDetected = false; // Status deteksi tangan sebelumnya

void setup() {
pinMode(trig, OUTPUT);
pinMode(echo, INPUT);
pinMode(relay, OUTPUT);
Serial.begin(9600);
}

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

  // Baca waktu pantulan
  long duration = pulseIn(echo, HIGH);

  // Hitung jarak (cm)
  float distance = (duration * 0.034) / 2;

  // Tampilkan jarak di Serial Monitor
  Serial.print("Jarak: ");
  Serial.print(distance);
  Serial.println(" cm");
  // Ambang batas jarak deteksi (misalnya 10 cm)
  if (distance < 10) {
    if (!handDetected) { // Jika tangan baru saja terdeteksi
      ledState = !ledState; // Ubah status LED
      digitalWrite(relay, ledState ? HIGH : LOW); // Kendalikan LED
      handDetected = true; // Tandai bahwa tangan terdeteksi
    }
  } else {
    handDetected = false; // Reset status deteksi jika tangan menjauh
  }

delay(500);
}