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

#define ROW_NUM     4 
#define COLUMN_NUM  4 

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

byte pin_rows[ROW_NUM] = {9, 8, 7, 6};
byte pin_column[COLUMN_NUM] = {5, 4, 3, 2};

Keypad keypad = Keypad(makeKeymap(keys), pin_rows, pin_column, ROW_NUM, COLUMN_NUM);
LiquidCrystal_I2C lcd(0x27, 16, 2);

String password = "1234";
String input = "";

void setup() {
  lcd.begin(16, 2);
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Enter Password:");
}

void loop() {
  char key = keypad.getKey();
  if (key) {
    if (key == '#') {
      if (input == password) {
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Access Granted");
      } else {
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Wrong Password");
        delay(2000);
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Enter Password:");
      }
      input = "";
    } else if (key == '*') {
      input = "";
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Enter Password:");
    } else {
      input += key;
      lcd.setCursor(0, 1);
      lcd.print(input);
    }
  }
}