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

LiquidCrystal_I2C lcd(0x27, 16, 2); // Ganti 0x27 jika alamat I2C berbeda

const int btnMenu = 2;
const int btnBack = 3;

int menuState = 0; // 0 = layar utama, 1 = Menu1, dst
int maxMenu = 3;

bool lastBtnMenu = HIGH;
bool lastBtnBack = HIGH;

void setup() {
  pinMode(btnMenu, INPUT_PULLUP);
  pinMode(btnBack, INPUT_PULLUP);

  lcd.init();
  lcd.backlight();

  tampilkanMenu();
}

void loop() {
  bool currentBtnMenu = digitalRead(btnMenu);
  bool currentBtnBack = digitalRead(btnBack);

  // Tombol menu ditekan
  if (currentBtnMenu == LOW && lastBtnMenu == HIGH) {
    menuState++;
    if (menuState > maxMenu) menuState = 1; // loop menu 1-3
    tampilkanMenu();
    delay(200); // debounce sederhana
  }

  // Tombol back ditekan
  if (currentBtnBack == LOW && lastBtnBack == HIGH) {
    menuState = 0; // kembali ke layar utama
    tampilkanMenu();
    delay(200);
  }

  lastBtnMenu = currentBtnMenu;
  lastBtnBack = currentBtnBack;
}

void tampilkanMenu() {
  lcd.clear();
  if (menuState == 0) {
    lcd.setCursor(0, 0);
    lcd.print("Ini layar utama");
  } else {
    lcd.setCursor(0, 0);
    lcd.print("Menu ");
    lcd.print(menuState);
  }
}