#include <Servo.h>

// Pin definitions for ultrasonic sensor
const int trigPin = 5; // Pin trig untuk sensor ultrasonik
const int echoPin = 18; // Pin echo untuk sensor ultrasonik

// Pin definition for servo motor
const int servoPin = 13;
Servo servoMotor;

// Threshold distance to open gate (in cm)
const int openDistance = 10;

// Variables for ultrasonic sensor
long duration;
int distance;

void setup() {
  // Initialize the serial communication for debugging
  Serial.begin(115200);

  // Set trigPin as output and echoPin as input
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  // Attach servo motor to the specified pin
  servoMotor.attach(servoPin);

  // Start with the gate closed (set servo to 0 degrees)
  servoMotor.write(0);
}

void loop() {
  // Send a 10us pulse to trigger the ultrasonic sensor
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Read the echo pin and calculate the distance
  duration = pulseIn(echoPin, HIGH);
  distance = duration * 0.034 / 2; // Convert to cm

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

  // If distance is less than or equal to threshold, open the gate
  if (distance <= openDistance) {
    Serial.println("Vehicle detected! Opening gate...");
    servoMotor.write(90); // Open the gate (90 degrees)
  } else {
    Serial.println("No vehicle detected. Closing gate...");
    servoMotor.write(0); // Close the gate (0 degrees)
  }

  // Wait for 500ms before the next reading
  delay(500);
}