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

// LCD Address (Most Wokwi LCDs use 0x27)
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Ultrasonic Sensor Pins
const int trigPin = 3;
const int echoPin = 2;

long duration;
float distance;

void setup() {

  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  lcd.init();
  lcd.backlight();

  Serial.begin(9600);

  lcd.setCursor(0,0);
  lcd.print("Ultrasonic");
  lcd.setCursor(0,1);
  lcd.print("Distance Meter");

  delay(2000);
  lcd.clear();
}

void loop() {

  // Clear Trigger
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);

  // Send 10us pulse
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Read Echo
  duration = pulseIn(echoPin, HIGH);

  // Calculate Distance
  distance = duration * 0.0343 / 2;

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

  // LCD Display
  lcd.clear();

  lcd.setCursor(0,0);
  lcd.print("Distance:");

  lcd.setCursor(0,1);
  lcd.print(distance,1);
  lcd.print(" cm");

  delay(500);
}