#include <Servo.h>

// pin sensor jarak 
const int trigPin = 2;
const int echoPin = 3;

// pin aktuator motor servo
const int servoPin = 5;

// Pin lampu LED
const int ledPin = 7;

// Pin Buzzer 
const int buzzerPin = 8;

Servo servo;

void setup () {
  pinMode (trigPin,OUTPUT );
  pinMode (echoPin, INPUT);
  pinMode (ledPin, OUTPUT);
  pinMode (buzzerPin,OUTPUT);

  servo.attach(servoPin);
  servo.write(0); // posisi awal palang pintu tertutup

  Serial.begin(9600);
}

  void loop () {
    long duration , distance;
    digitalWrite(trigPin,LOW);
    delayMicroseconds (2);
    digitalWrite(trigPin, HIGH);
    delayMicroseconds (10);
    digitalWrite(trigPin, LOW);
    duration = pulseIn (echoPin,HIGH);

    // menghitung jarak 
    distance = duration * 0.034/2;

    if (distance > 0 && distance < 10) {
      openGate();
      blinkLEDAndBuzzer();
    } else {
      closeGate();
      turnOffLEDAndBuzzer();
    }

    delay (100);
  }

  void openGate(){
  servo.write(90);
  delay(1000);
}

void closeGate(){
  servo.write(0);
  delay(1000);
}

void blinkLEDAndBuzzer() {
  digitalWrite(ledPin, HIGH);
  tone(buzzerPin, 1000);
  delay (500);
  digitalWrite(ledPin, LOW);
  tone(buzzerPin, 500);
  delay(500);
}

void turnOffLEDAndBuzzer() {
  digitalWrite(ledPin, LOW);
  noTone(buzzerPin);
}