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

// Define LCD pins
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;

// Define Ultrasonic Sensor pins
const int trigPin = 9;
const int echoPin = 10;

// Define Servo pin
const int servoPin = 6;

LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
Servo servo;

void setup() {
  lcd.begin(16, 2); // Initialize LCD
  pinMode(trigPin, OUTPUT); // Set trigPin as OUTPUT
  pinMode(echoPin, INPUT); // Set echoPin as INPUT
  servo.attach(servoPin); // Attach servo to pin
  Serial.begin(9600); // Initialize serial communication

  lcd.setCursor(0, 0);
  lcd.print("Initializing device");
  delay(2000);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Device started");
  lcd.setCursor(0, 1);
  lcd.print("successfully");
  delay(2000);
}

void loop() {
  // Clear LCD
  lcd.clear();

  // Calculate distance using Ultrasonic Sensor
  float distance = calculateDistance();

  // Display distance on LCD
  lcd.setCursor(0, 0);
  lcd.print("Distance: ");
  lcd.print(distance);
  lcd.print(" cm");

  // Display distance on Serial Monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  // Check threshold distance
  if (distance <= 50) {
    // Open door
    servo.write(90);
    lcd.setCursor(0, 1);
    lcd.print("Door Open");
    Serial.println("Door Open");
  } else {
    // Close door
    servo.write(0);
    lcd.setCursor(0, 1);
    lcd.print("Door Closed");
    Serial.println("Door Closed");
  }

  delay(1000); // Update distance every 1 second
}

float calculateDistance() {
  // Send ultrasonic pulse
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Measure echo time
  long echoTime = pulseIn(echoPin, HIGH);

  // Calculate distance
  float distance = echoTime * 0.034 / 2;
  return distance;
}