#include <Servo.h>

#define TRIG_PIN 9
#define ECHO_PIN 10

#define SERVO_PIN 3
#define LED_PIN 4

Servo lockServo;

void setup() {

  Serial.begin(9600);

  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);

  pinMode(LED_PIN, OUTPUT);

  lockServo.attach(SERVO_PIN);

  lockServo.write(0);

  Serial.println("SENTRY ALPHA READY");
}

void loop() {

  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);

  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);

  digitalWrite(TRIG_PIN, LOW);

  long duration = pulseIn(ECHO_PIN, HIGH);

  float distance = duration * 0.034 / 2;

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

  if (distance < 10) {

    Serial.println("AKSES TERDETEKSI");

    digitalWrite(LED_PIN, HIGH);

    lockServo.write(90);

    delay(3000);

    lockServo.write(0);

    digitalWrite(LED_PIN, LOW);

    delay(1000);
  }

  delay(200);
}