#include <Servo.h>

Servo servo;  

// Pin Ultrasonic
const int trigPin = 3;
const int echoPin = 5;

// Pin Servo
const int servoPin = 9;

long duration;
int distance;

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

  servo.attach(servoPin);
  servo.write(0); // posisi awal servo
}

void loop() {
  // Kirim pulsa ultrasonic
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Hitung waktu pantulan
  duration = pulseIn(echoPin, HIGH);
  
  // Konversi ke jarak (cm)
  distance = duration * 0.034 / 2;

  Serial.print("Jarak: ");
  Serial.print(distance);
  Serial.println(" cm");

  if (distance > 0 && distance < 10) {  
    // Jika tangan terdeteksi < 15 cm
    servo.write(90);   // Servo tekan pump
    delay(1000);       // Tahan 1 detik
    servo.write(0);    // Kembali ke posisi semula
    delay(2000);       // Tunggu 2 detik sebelum deteksi ulang
  }
}