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

LiquidCrystal_I2C lcd(0x27, 16, 2);
const uint8_t ROWS = 4;
const uint8_t COLS = 4;

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

uint8_t colPins[COLS] = { 5, 4, 3, 2 };
uint8_t rowPins[ROWS] = { 9, 8, 7, 6 };
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

// Password setup
String correctPassword = "1234"; // Set your password here
String enteredPassword = "";

void setup() {
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();
  lcd.clear();
  lcd.print("Enter Password:");
  lcd.setCursor(0, 1);  // Move to the second row for input
}

void loop() {
  char key = keypad.getKey();

  if (key != NO_KEY) {
    if (key >= '0' && key <= '9') { // Check if the key is a number
      enteredPassword += key;  // Append the entered key to the password string
      lcd.print("*");  // Display asterisk for each digit
    } 
    else if (key == '#') { // '#' as 'Enter' to submit the password
      if (enteredPassword == correctPassword) {
        lcd.clear();
        lcd.print("Access Granted");
        lcd.setCursor(0, 1);
        lcd.print("Unlocked!");
        analogWrite(A0, 255);  // Example: Set A0 to HIGH for unlocking

        delay(3000); // Display the unlocked message for 3 seconds
        lcd.clear();
        lcd.print("Enter Password:");
      } else {
        lcd.clear();
        lcd.print("Access Denied");
        lcd.setCursor(0, 1);
        lcd.print("Try Again");

        delay(3000); // Display access denied for 3 seconds
        lcd.clear();
        lcd.print("Enter Password:");
      }
      enteredPassword = "";  // Clear the entered password after checking
    } 
    else if (key == '*') { // '*' as 'Clear' to reset the input
      enteredPassword = "";
      lcd.clear();
      lcd.print("Enter Password:");
      lcd.setCursor(0, 1);
    }
  }
}