/* 
 * Created by ArduinoGetStarted.com
 * 
 * This example code is in the public domain
 * 
 * Tutorial page: [Arduino - Ultrasonic Sensor - LCD](https://arduinogetstarted.com/tutorials/arduino-ultrasonic-sensor-lcd)
 */

#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C address 0x27 (from DIYables LCD), 16 columns and 2 rows

int trigPin = 9; // TRIG pin
int echoPin = 10; // ECHO pin
float duration_us, distance_cm;

void setup() {
    lcd.init(); // Initialize the LCD
    lcd.backlight(); // Turn on the backlight
    pinMode(trigPin, OUTPUT); // Configure the trigger pin as output
    pinMode(echoPin, INPUT); // Configure the echo pin as input
}

void loop() {
    // Generate a 10-microsecond pulse to the TRIG pin
    digitalWrite(trigPin, HIGH);
    delayMicroseconds(10);
    digitalWrite(trigPin, LOW);

    // Measure the duration of the pulse from the ECHO pin
    duration_us = pulseIn(echoPin, HIGH);

    // Calculate the distance in centimeters
    distance_cm = 0.017 * duration_us;

    // Display the distance on the LCD
    lcd.clear();
    lcd.setCursor(0, 0); // Start printing at the first row
    lcd.print("Distance: ");
    lcd.print(distance_cm);

    delay(500); // Wait for a moment before measuring again
}