#include <LiquidCrystal.h>

const int buzzerPin = 8;
const int buttonPin = 2;
const int ledPin = 13;
const int maxAttempts = 3; // Set the maximum number of incorrect attempts

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

const char correctPIN[] = "1234"; // Set your desired PIN

char enteredPIN[5]; // Array to store entered PIN
int attempts = 0;

void setup() {
  lcd.begin(16, 2);
  lcd.print("Enter PIN:");

  pinMode(buttonPin, INPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(ledPin, OUTPUT);
}

void loop() {
  readPIN();

  if (checkPIN()) {
    deactivateAlarm();
  } else {
    attempts++;
    lcd.clear();
    lcd.print("Incorrect! Try again");
    delay(2000);
    lcd.clear();
    lcd.print("Enter PIN:");
    
    if (attempts >= maxAttempts) {
      activateAlarm();
      lcd.clear();
      lcd.print("Alarm Activated!");
      while (true) {
        // Loop indefinitely when alarm is activated
      }
    }
  }
}

void readPIN() {
  for (int i = 0; i < 4; i++) {
    char key = getKey();
    if (key != '\0') {
      enteredPIN[i] = key;
      lcd.setCursor(i, 1);
      lcd.print('*');
    }
  }
  enteredPIN[4] = '\0';
}

char getKey() {
  char key = '\0';
  while (digitalRead(buttonPin) == HIGH) {
    // Wait for the button to be pressed
  }
  delay(50); // Debounce delay
  if (digitalRead(buttonPin) == LOW) {
    key = keypad.getKey();
    while (digitalRead(buttonPin) == LOW) {
      // Wait for the button to be released
    }
  }
  return key;
}

bool checkPIN() {
  return strcmp(enteredPIN, correctPIN) == 0;
}

void activateAlarm() {
  lcd.clear();
  lcd.print("Too Many Attempts!");
  digitalWrite(ledPin, HIGH);
  tone(buzzerPin, 1000, 2000); // Activate alarm sound for 2 seconds
}

void deactivateAlarm() {
  lcd.clear();
  lcd.print("PIN Accepted!");
  digitalWrite(ledPin, LOW);
  noTone(buzzerPin); // Stop alarm sound
  delay(2000);
  lcd.clear();
  lcd.print("Alarm Deactivated");
  while (true) {
    // Loop indefinitely when alarm is deactivated
  }
}