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

LiquidCrystal_I2C lcd(0x27, 16, 2);  // I2C address 0x27, 16 columns and 2 rows

const int trigPin = 8;     // Digital pin connected to the Trigger pin of the ultrasonic sensor
const int echoPin = 7;    // Digital pin connected to the Echo pin of the ultrasonic sensor
const int buzzerPin = 6;   // Digital pin connected to the buzzer

void setup() {
  lcd.init();          // Initialize the LCD
  lcd.backlight();     // Turn on the backlight
  lcd.setCursor(0, 0); // Set cursor to the first column and first row

  pinMode(trigPin, OUTPUT);  // Set the Trig pin as an output
  pinMode(echoPin, INPUT);   // Set the Echo pin as an input
  pinMode(buzzerPin, OUTPUT); // Set the buzzer pin as an output
}

void loop() {
  // Measure the distance using the ultrasonic sensor
  long duration, distance;
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = duration * 0.034 / 2;

  // Display distance on the LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Distance: ");
  lcd.print(distance);
  lcd.print(" cm");

  // Check distance and display messages on LCD, activate buzzer
  if (distance >= 20) {
    lcd.setCursor(0, 1);
    lcd.print("Safe Distance");
    noTone(buzzerPin);
  } else if (distance < 20 && distance >= 15) {
    lcd.setCursor(0, 1);
    lcd.print("Be Careful");
    tone(buzzerPin, 1000, 500);
  } else if (distance < 15 && distance >= 8) {
    lcd.setCursor(0, 1);
    lcd.print("Distance NOT Safe");
    tone(buzzerPin, 2000, 500);
  } else {
    lcd.setCursor(0, 1);
    lcd.print("Too Close!");
    tone(buzzerPin, 3000, 500);
  }

  delay(1000);  // Delay for 1 second before taking the next measurement
}