#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// Define the ultrasonic sensor pins
#define trigPin 9
#define echoPin 10

// Create an LCD object with the I2C address 0x27 and 16 columns, 2 rows
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Variable to store the duration of the pulse and distance
long duration;
int distance;

void setup() {
  // Initialize the serial monitor
  Serial.begin(9600);
  
  // Initialize the ultrasonic sensor pins
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  
  // Initialize the LCD
  lcd.begin(16, 2);
  lcd.setCursor(0, 0);
  lcd.print("Distance Sensor");
  delay(2000);  // Display the message for 2 seconds
  
  // Clear the LCD screen
  lcd.clear();
}

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

  // Measure the duration of the pulse received on the echo pin
  duration = pulseIn(echoPin, HIGH);

  // Calculate the distance in centimeters
  distance = duration * 0.0344 / 2;  // Speed of sound is 0.0344 cm/µs, divide by 2 for round-trip
  
  // Display the distance on the LCD
  lcd.setCursor(0, 0);  // Set the cursor to the first row
  lcd.print("Distance: ");
  lcd.print(distance);   // Print the distance value
  lcd.print(" cm");
  
  // Print the distance to the Serial Monitor (optional)
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  // Wait for a short time before the next reading
  delay(500);  // Update every 500 milliseconds
}