#include <LiquidCrystal_I2C.h>// Include LiquidCrystal_I2C library

#define PIR_SENSOR_PIN 2
#define ULTRASONIC_TRIGGER_PIN 3
#define ULTRASONIC_ECHO_PIN 4
#define BUZZER_PIN 5
#define LED_PIN 6

const int threshold = 200; // Distance threshold in cm for proximity detection

const int lcd_address = 0x27; // I2C address of your LCD (may vary)
const int rows = 2;
const int cols = 16;

LiquidCrystal_I2C lcd(lcd_address, rows, cols);

void setup() {
  pinMode(PIR_SENSOR_PIN, INPUT);
  pinMode(ULTRASONIC_TRIGGER_PIN, OUTPUT);
  pinMode(ULTRASONIC_ECHO_PIN, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(LED_PIN, OUTPUT);

  lcd.init();
  lcd.backlight(); // Optional: turn on LCD backlight
lcd.print("Welcome Benneth ");
delay(1000);
}

void loop() {
  if (digitalRead(PIR_SENSOR_PIN) == HIGH) {
    int distance = measureDistance();

    if (distance <= threshold) {
      digitalWrite(BUZZER_PIN, HIGH);
      digitalWrite(LED_PIN, HIGH);
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Intruder!");
      lcd.setCursor(0, 1);
      lcd.print("Distance: ");
      lcd.print(distance);
      lcd.print("cm");
      delay(1000); // Alarm duration
    } else {
      // Object detected but not close enough, optional indication
      digitalWrite(LED_PIN, LOW); // Replace with desired indication logic
      delay(500);
    }
  } else {
    lcd.clear(); // Clear LCD when no motion detected
    digitalWrite(BUZZER_PIN, LOW);
    digitalWrite(LED_PIN, LOW);
    lcd.print("No Danger,Keep Calm ");
  }
  delay(500); // Adjust delay based on desired checking frequency
}

int measureDistance() {
  // ... same as previous implementation ...
  // Trigger ultrasonic sensor
  digitalWrite(ULTRASONIC_TRIGGER_PIN, HIGH);
  delayMicroseconds(2);
  digitalWrite(ULTRASONIC_TRIGGER_PIN, LOW);

  // Measure echo pulse duration
  long duration = pulseIn(ULTRASONIC_ECHO_PIN, HIGH);

  // Calculate distance (speed of sound * echo duration / 2)
  return duration * 0.034 / 2;
}