#include <Keypad.h>
#include <LiquidCrystal_I2C.h>

const int redLedPin = 13;
const int greenLedPin = 12;
const int buzzerPin = 11;

const int ROWS = 4;
const int COLS = 4;

const char password[4] = "1234";

char keys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};

byte rowPins[ROWS] = {0, 1, 2, 3};
byte colPins[COLS] = {4, 5, 6, 7};

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  lcd.begin(16, 2);
  pinMode(redLedPin, OUTPUT);
  pinMode(greenLedPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);
}

void loop() {
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Enter password:");

  char enteredPassword[5];
  int i = 0;

  while (i < 4) {
    char key = keypad.getKey();
    if (key) {
      enteredPassword[i++] = key;
      lcd.setCursor(i-1, 1);
      lcd.print("*");
    }

  if (strcmp(enteredPassword, password) == 0) {
    // Correct password
    digitalWrite(greenLedPin, HIGH);
    digitalWrite(redLedPin, LOW);
    digitalWrite(buzzerPin, LOW);
    lcd.clear();
    lcd.print("Password OK!");
    delay(2000);
  } else {
    // Incorrect password
    digitalWrite(greenLedPin, LOW);
    digitalWrite(redLedPin, HIGH);
    digitalWrite(buzzerPin, HIGH);
    lcd.clear();
    lcd.print("Incorrect Password!");
    delay(2000);
  }
}
}