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

#define TRIG_PIN 18
#define ECHO_PIN 19
#define BUZZER 32

// Setup the LCD
LiquidCrystal_I2C LCD = LiquidCrystal_I2C(0x27, 16, 2);

void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(BUZZER, OUTPUT);

  // Initialize the display and display the initial message
  LCD.init();
  LCD.backlight();
  LCD.setCursor(0, 0);
  LCD.print("Social Distancing");
  LCD.setCursor(0, 1);
  LCD.print("Alert System");
  delay(1000);
}

void loop() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  int duration = pulseIn(ECHO_PIN, HIGH);
  int distance = duration * 0.034 / 2;

  if (distance < 100) {
    // Display warning on LCD
    LCD.clear();
    LCD.setCursor(0, 0);
    LCD.print("Alert! Maintain");
    LCD.setCursor(0, 1);
    LCD.print("1m Distance!");
    delay(2000);  // Display warning for 2 seconds

    // Sound the buzzer for 2 seconds
    tone(BUZZER, 1000);  // For example, 1000 Hz
    delay(2000);  // Buzzer sounds for 2 seconds
    noTone(BUZZER);
  } else {
    // Display safe distance on LCD
    LCD.clear();
    LCD.setCursor(0, 0);
    LCD.print("Safe Area");
    LCD.setCursor(0, 1);
    LCD.print("Distance: ");
    LCD.print(distance);
    LCD.print(" cm");
    delay(1000);  // Display safe distance for 1 second

    // Turn off the buzzer
    noTone(BUZZER);
  }

  // Wait for a moment before the next reading
  delay(1000);
}