#include <Wire.h>  // Library for I2C communication
#include <LiquidCrystal_I2C.h>  // Library for I2C LCD
#include <Keypad.h>


LiquidCrystal_I2C lcd(0x27, 20, 4); 
//Mengatur jumlah baris dan kolom pada keypad
const int ROWS = 4;
const int COLS = 4;
char keys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};

byte rowPins[ROWS] = {19, 18, 5, 17}; // Pins baris keypad
byte colPins[COLS] = {16, 4, 0, 2}; // Pins kolom keypad

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

const int greenLedPin = 26; // Pin untuk LED hijau
const int redLedPin = 27;   // Pin untuk LED merah
const String password = "7890"; // Password yang diharapkan

void setup() {
  pinMode(greenLedPin, OUTPUT);
  pinMode(redLedPin, OUTPUT);
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0,0);
  lcd.print("Masukkan Password:");
}

String enteredPassword = ""; // Variabel untuk menyimpan karakter yang dimasukkan

void loop() {
  char key = keypad.getKey();
  
  if (key) {
    if (key == '*') { // Menghapus karakter
      if (enteredPassword.length() > 0) {
        enteredPassword.remove(enteredPassword.length() - 1);
        lcd.setCursor(enteredPassword.length(), 1);
        lcd.print(" ");
      }
    } else if (key == '#') { // Memverifikasi password
      if (enteredPassword == password) {
        lcd.clear();
        lcd.print("Password Benar!");
        digitalWrite(greenLedPin, HIGH);
        delay(2000);
        digitalWrite(greenLedPin, LOW);
        lcd.clear();
        lcd.print("Masukkan Password:");
        enteredPassword = "";
      } else {
        lcd.clear();
        lcd.print("Password Salah!");
        digitalWrite(redLedPin, HIGH);
        delay(2000);
        digitalWrite(redLedPin, LOW);
        lcd.clear();
        lcd.print("Masukkan Password:");
        enteredPassword = "";
      }
    } else { // Menambahkan karakter
      enteredPassword += key;
      lcd.setCursor(enteredPassword.length() - 1, 1);
      lcd.print("*");
    }
  }
}