#include <Servo.h>

const int trigPin = 11;
const int echoPin = 10;
const int servoPin = 9;

Servo myservo;

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

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("Distance: ");
  Serial.println(distance);

  if (distance >= 0 && distance <= 50) {
    myservo.write(90); // Putar servo 90 derajat
  } else {
    myservo.write(0); // kembali ke posisi awal
  }
  delay(100);
}