#include <Wire.h>                // For I2C communication
#include <LiquidCrystal_I2C.h>   // Library for I2C LCD

// Set the LCD address to 0x27 (adjust if necessary), with 16 columns and 2 rows
LiquidCrystal_I2C lcd(0x27, 16, 2); 

// Define pins for HC-SR04
const int trigPin = 9;
const int echoPin = 10;

void setup() {
  lcd.begin(16, 2);  // Initialize the LCD with 16 columns and 2 rows
  lcd.backlight();   // Turn on the LCD backlight
  
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
}

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

  // Measure the duration of the echo pulse
  long duration = pulseIn(echoPin, HIGH);

  // Calculate the distance in cm
  float distance = duration * 0.034 / 2;

  // Print the distance on the LCD
  lcd.clear();
  lcd.setCursor(0, 0);  // Set cursor to the first row, first column
  lcd.print("Distance: ");
  lcd.print(distance);
  lcd.print(" cm");

  delay(500);  // Delay to avoid rapid updates
}