#include <Wire.h>
#include <LiquidCrystal_PCF8574.h>

#define MOTION_SENSOR_PIN 2  // Pin connected to the motion sensor
#define LED_PIN 13           // Pin connected to the red LED

// LCD object (adjust I2C address if necessary)
LiquidCrystal_PCF8574 lcd(0x27);

int motion_state = LOW;      // Current state of the motion sensor
int prev_motion_state = LOW; // Previous state of the motion sensor

void setup() {
  Serial.begin(9600);        // Initialize Serial communication
  pinMode(MOTION_SENSOR_PIN, INPUT); // Set motion sensor pin to input mode
  pinMode(LED_PIN, OUTPUT);          // Set LED pin to output mode

  // Initialize LCD
  lcd.begin(16, 2);
  lcd.setBacklight(255);

  // Display initial message
  lcd.setCursor(0, 0);
  lcd.print("House Status:");
  lcd.setCursor(0, 1);
  lcd.print("Secure");
}

void loop() {
  // Update the state of the motion sensor
  prev_motion_state = motion_state;
  motion_state = digitalRead(MOTION_SENSOR_PIN);

  // Check if motion is detected
  if (prev_motion_state == LOW && motion_state == HIGH) {
    // Motion detected, intruder detected
    Serial.println("Intruder Detected!");
    blinkLED();

    // Update LCD with intruder status
    lcd.setCursor(0, 1);
    lcd.print("Intruder Detected");
  }

  delay(100); // Small delay to avoid bouncing issues
}

// Function to blink the red LED
void blinkLED() {
  for (int i = 0; i < 5; i++) {
    digitalWrite(LED_PIN, HIGH); // Turn on the LED
    delay(500); // Wait for 500 milliseconds
    digitalWrite(LED_PIN, LOW); // Turn off the LED
    delay(500); // Wait for 500 milliseconds
  }
}