#include <LiquidCrystal.h>

// Initialize the LCD library (RS, EN, D4, D5, D6, D7)
LiquidCrystal lcd(7, 6, 5, 4, 3, 2);

#define trigPin 9  // Trig pin of ultrasonic sensor
#define echoPin 10 // Echo pin of ultrasonic sensor

void setup() {
  lcd.begin(16, 2);  // Set up the LCD's number of columns and rows
  lcd.print("Distance:"); // Initial text
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
}

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

  // Measure time taken by echo to return
  long duration = pulseIn(echoPin, HIGH);

  // Convert the time into distance (cm)
  int distance = duration / 58;

  // Clear previous value and set cursor
  lcd.setCursor(0, 1);
  lcd.print("                "); // Clear the second row
  lcd.setCursor(0, 1);
  
  // Display the distance
  lcd.print(distance);
  lcd.print(" cm");

  delay(500);  // Delay for readability
}