#define echoPin 12 // attach pin D2 Arduino to pin Echo of HC-SR04
#define trigPin 13 //attach pin D3 Arduino to pin Trig of HC-SR04
#include <Servo.h>


// defines variables
long duration; // variable for the duration of sound wave travel
int distance; // variable for the distance measurement
const int servoPin = 9; // Pin kontrol servo motor
Servo myservo; 

void setup() {
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an OUTPUT
  pinMode(echoPin, INPUT); // Sets the echoPin as an INPUT
  Serial.begin(9600); // // Serial Communication is starting with 9600 of baudrate speed
  Serial.println("Ultrasonic Sensor HC-SR04 Test"); // print some text in Serial Monitor
  Serial.println("with Arduino UNO R3");
  myservo.attach(servoPin);
}
void loop() {
  // Clears the trigPin condition
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  // Sets the trigPin HIGH (ACTIVE) for 10 microseconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  // Reads the echoPin, returns the sound wave travel time in microseconds
  duration = pulseIn(echoPin, HIGH);
  // Calculating the distance
  distance = duration * 0.034 / 2; // Speed of sound wave divided by 2 (go and back)
  // Displays the distance on the Serial Monitor
  
  Serial.println(distance);
  if (distance < 17) {
    myservo.write(270); // Putar servo ke posisi 0 derajat (arah kanan)
    Serial.println("buka pintu");
  } else if (distance == 19) {
    myservo.write(0); // Putar servo ke posisi 180 derajat (arah kiri)
    Serial.println("tutup pintu");
  } else {
    myservo.write(0); // Putar servo ke posisi 90 derajat (arah tengah)
    Serial.println("tutup pintu");
  }
}