#define trigPin 9
#define echoPin 10
#define buzzerPin 11

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

void loop() {
  long duration, distance;
  
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  duration = pulseIn(echoPin, HIGH);
  
  distance = (duration * 0.034) / 2;
  
  Serial.print("Jarak: ");
  Serial.print(distance);
  Serial.println(" cm");
  
  if (distance > 100) {
    analogWrite(buzzerPin, LOW);
  } else {
    analogWrite(buzzerPin, HIGH);
  }
  
  delay(1000);
}