#include <Servo.h>
#include <LiquidCrystal.h>


const int trigPin1 = 8;
const int echoPin1 = 9;
const int trigPin2 = 10;
const int echoPin2 = 11;
const int trigPin3 = 12;
const int echoPin3 = 13;

const int greenLed = 13;
const int redLed = 12;


Servo myServo;


LiquidCrystal lcd(7, 6, 5, 4, 3, 2);


int vehicleCount = 0;

void setup() {

  pinMode(trigPin1, OUTPUT);
  pinMode(echoPin1, INPUT);
  pinMode(trigPin2, OUTPUT);
  pinMode(echoPin2, INPUT);
  pinMode(trigPin3, OUTPUT);
  pinMode(echoPin3, INPUT);


  pinMode(greenLed, OUTPUT);
  pinMode(redLed, OUTPUT);

  lcd.begin(16, 2);

 
  myServo.attach(9);

  lcd.print("Roll No: 2347125");
  delay(2000);
  lcd.clear();


  myServo.write(0);
}

void loop() {
  long duration1, distance1;
  long duration2, distance2;
  long duration3, distance3;


  digitalWrite(trigPin1, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin1, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin1, LOW);
  duration1 = pulseIn(echoPin1, HIGH);
  distance1 = (duration1 / 2) / 29.1;

  digitalWrite(trigPin2, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin2, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin2, LOW);
  duration2 = pulseIn(echoPin2, HIGH);
  distance2 = (duration2 / 2) / 29.1;

  digitalWrite(trigPin3, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin3, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin3, LOW);
  duration3 = pulseIn(echoPin3, HIGH);
  distance3 = (duration3 / 2) / 29.1;

  if (distance1 < 10) {
    if (vehicleCount < 3) {
      vehicleCount++;
      lcd.clear();
      lcd.print("Vehicle Entered");
      myServo.write(90);
      delay(2000);
      myServo.write(0);
    } else {
      lcd.clear();
      lcd.print("Parking Full");
    }
  }

  if (distance2 < 10) {
    if (vehicleCount > 0) {
      vehicleCount--;
      lcd.clear();
      lcd.print("Vehicle Exited");
      myServo.write(90);
      delay(2000);
      myServo.write(0);
    }
  }

  if (vehicleCount == 3) {
    digitalWrite(redLed, HIGH);
    digitalWrite(greenLed, LOW);
    lcd.clear();
    lcd.print("Parking Full");
  } else {
    digitalWrite(redLed, LOW);
    digitalWrite(greenLed, HIGH);
    lcd.clear();
    lcd.print("Parking Space: ");
    lcd.setCursor(0, 1);
    lcd.print(3 - vehicleCount);
  }

  delay(500);
}