int pinTrig = 2;
int pinEcho = 3;
int pinBuzzer = 5;
int pinLed = 13;
void setup() {
  // put your setup code here, to run once:
  pinMode(pinTrig, OUTPUT);
  pinMode(pinEcho, INPUT);
  pinMode(pinBuzzer, OUTPUT);
  pinMode(pinLed, OUTPUT);
}

void loop() {
// put your main code here, to run repeatedly:
  digitalWrite(pinTrig, LOW);
  delayMicroseconds(2);
  digitalWrite(pinTrig, HIGH);
  delayMicroseconds(10);
  digitalWrite(pinTrig, LOW);
  long duration = pulseIn(pinEcho, HIGH);

//menghitung jarak
float distance = duration*0.034/2;
 if (distance <= 40) {
    digitalWrite(pinLed, HIGH); // Nyalakan LED jika jarak <= 40 cm
  } else {
    digitalWrite(pinLed, LOW);  // Matikan LED jika jarak > 40 cm
  }
  if (distance <= 30) {
    tone(pinBuzzer, 1000); // Aktifkan buzzer jika jarak <= 30 cm
  } else {
    noTone(pinBuzzer);
  }
delay(100);
}