#include <LiquidCrystal_I2C.h>
#include <Keypad.h>
#include <Servo.h>
LiquidCrystal_I2C lcd(0x27, 20, 4);
int stage = 1;
const int TrueLED = 13;
const int FalseLED = 12;
const int LED = 11;
const int buzzerPin = 8;
const byte ROWS = 4;
const byte COLS = 4;
char Keys[ROWS][COLS] = {
  { '1', '2', '3', 'A' },
  { '4', '5', '6', 'B' },
  { '7', '8', '9', 'C' },
  { '*', '0', '#', 'D' }
};
byte rowPins[ROWS] = { 7, 6, 5, 4 };
byte colPins[COLS] = { 3, 2, 1, 0 };
Keypad customKeypad = Keypad(makeKeymap(Keys), rowPins,
                             colPins, ROWS, COLS);
String inputPassword = "";
String passwords[3] = { "123A", "456B", "789C" };
Servo servoX;
Servo servoY;
void setup() {
  lcd.init();
  lcd.backlight();
  pinMode(TrueLED, OUTPUT);
  pinMode(FalseLED, OUTPUT);
  pinMode(LED, OUTPUT);
  pinMode(buzzerPin, OUTPUT);
  servoX.attach(10);
  servoY.attach(9);
  servoX.write(0);
  servoY.write(0); 
}
void loop() {
  lcd.setCursor(0, 0);
  lcd.print("Kode Akses ");
  lcd.print(stage);
  lcd.print(": ");
  char customKey = customKeypad.getKey();
  if ((customKey >= '0' && customKey <= '9') || 
      (customKey >= 'A' && customKey <= 'D')) {
    inputPassword += customKey;
    lcd.setCursor(0, 1);
    lcd.print(inputPassword);
    if (inputPassword.length() == 4) {
      delay(1000);
      checkPassword(); }
  }
  if (customKey == '*') {
    inputPassword = "";
    lcd.clear(); }
  for (int i = inputPassword.length(); i < 4; i++) {
    lcd.setCursor(i, 1);
    lcd.print('X'); } 
  }
void checkPassword() {
  if (inputPassword == passwords[stage - 1]) {
    lcd.setCursor(0, 2);
    lcd.print("Kode Akses Benar");
    digitalWrite(LED, HIGH);
    tone(buzzerPin, 500, 400);
    delay(1000);
    digitalWrite(LED, LOW);
    lcd.clear();
    inputPassword = "";
    stage++;
    if (stage > 3) {
      lcd.setCursor(0, 0);
      lcd.print("Akses Diijinkan");
      digitalWrite(TrueLED, HIGH);
      servoX.write(180);
      delay(5000);
      digitalWrite(TrueLED, LOW);
      servoX.write(0);
      stage = 1;
      lcd.clear(); }
  } else {
    lcd.setCursor(0, 2);
    lcd.print("Kode Akses Salah");
    digitalWrite(FalseLED, HIGH);
    tone(buzzerPin, 75, 400);
    servoY.write(180);
    delay(1000);
    digitalWrite(FalseLED, LOW);
    servoY.write(0);
    inputPassword = "";
    lcd.clear(); }
}