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

LiquidCrystal_I2C lcd(0x27, 20, 4);

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

byte rowPin[ROWS] = {19,18,5,17};
byte colPin[COLS] = {16,4,0,2};

Keypad keypad = Keypad(makeKeymap(key), rowPin, colPin, ROWS, COLS);

String inputPassword = "";
String correctPassword = "1234"; 

void setup() {
  Serial.begin(115200);
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Check Your Pass");
}

void loop() {
  loginPass();
}

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

  if (key) {
    if (key == '#') {
      if (inputPassword == correctPassword) {
        Serial.println("Pass");
        lcd.setCursor(0, 1);
        lcd.print("Correct Password!");

      } else {
        Serial.println("NoPass");
        lcd.setCursor(0, 1);
        lcd.print("Wrong Password");

      }
      inputPassword = "";
    } else if (key == '*') {
      inputPassword = "";
      lcd.setCursor(0, 2);
      lcd.print("Enter:     ");

    } else {
      if (inputPassword.length() < 4) {
        inputPassword += key;
        lcd.setCursor(0, 2);
        lcd.print("Enter: ");
        lcd.print(inputPassword);
      }
    }
  }
}