#include <Servo.h>
#include <AccelStepper.h>

// Pin definitions
const int irPin = 2;
const int trigPin = 6;
const int echoPin = 5;
const int relayPin = 7;
const int servoPin = 9;
const int stepPin = 3;
const int dirPin = 4;
const int enablePin = 8;

// Servo setup
Servo barrierServo;

// Stepper setup (A4988)
AccelStepper stepper(AccelStepper::DRIVER, stepPin, dirPin);

// Variables
long duration;
float distance;

void setup() {
  // IR sensor
  pinMode(irPin, INPUT);
  
  // Ultrasonic
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  
  // Relay
  pinMode(relayPin, OUTPUT);
  digitalWrite(relayPin, LOW);

  Serial.begin(9600);
  
  // Servo
  barrierServo.attach(servoPin);
  barrierServo.write(0); // Barrier closed
  
  // Stepper
  pinMode(enablePin, OUTPUT);
  digitalWrite(enablePin, LOW); // Enable stepper


  stepper.setMaxSpeed(200); // Adjust speed
  stepper.setAcceleration(100);
}

void loop() {
  int irState = digitalRead(irPin);
  Serial.println(irState);
  delay(500);
  
  if (irState == HIGH) { // Vehicle detected
    // Lift barrier
    barrierServo.write(90);
    
    // Measure distance
    distance = getDistanceCM();
    
    // Turn on relay if vehicle < 20 cm
    if (distance < 20) {
      digitalWrite(relayPin, HIGH);
    } else {
      digitalWrite(relayPin, LOW);
    }
    
    // Rotate stepper while barrier is open
    stepper.moveTo(200); // Rotate 200 steps
    stepper.run();
    
    delay(1000); // Wait 1 second (optional for stability)
    
  } else {
    // No vehicle, reset
    barrierServo.write(0);  // Barrier down
    digitalWrite(relayPin, LOW); // Relay off
  }
}

// Function to measure distance using ultrasonic sensor
float getDistanceCM() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  duration = pulseIn(echoPin, HIGH);
  
  // Calculate distance in cm
  float distanceCM = (duration * 0.0343) / 2;
  return distanceCM;

  
 
}