GUI Funcionando Arduino

#include <LiquidCrystal.h>
//#include <iostream>

// select the pins used on the LCD panel

LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

// define some values used by the panel and buttons
int lcd_key     = 0;
int adc_key_in  = 0;

const int btnRIGHT = 0;
const int btnUP = 1;
const int btnDOWN = 2;
const int btnLEFT = 3;
const int btnSELECT = 4;
const int btnNONE = 5;

using namespace std;

class Noh;
void context_menu(Noh* option);

class MenuOption{
private:

public:
  char name[16]; // favor não usar o último caractere
  bool leads_to_another_menu;
  Noh* data;
  void select();
  MenuOption(){};
  MenuOption(char* new_name){
    int i = 0;
    bool string_end = false;
    for (int i = 0; i < 15; i++){
      if (string_end == false){
        if (new_name[i] == '\0'){
          string_end = true;
        }
        name[i] = new_name[i];
      }
      else{
        name[i] = ' ';
      }
    }
    name[16] = '\0';
  };
  ~MenuOption(){};
};

void MenuOption::select(){
  if (this->leads_to_another_menu){
    context_menu(data);
  }
}

class Noh
{
private:
  void* data; // o ponteiro do tipo void pode ser usado pra qualquer propósito
public:
  Noh* next;
  Noh* previous;
  MenuOption* asMenu(){return (MenuOption*)(data);}; // retorna data como um ponteiro para MenuOption
  //Skill* asSkill(){return (Skill*)(data);}; // retorna data como um ponteiro para Skill
  Noh(){
    next = NULL;
    previous = NULL;
    data = NULL;
  };
  Noh(void* new_data){
    data = new_data;
    next = NULL;
    previous = NULL;
  };
  ~Noh(){
    // remove ponteiros que apontam pra este objeto
    if (this->next->previous == this){
      this->next->previous = NULL;
    }
    if (this->previous->next == this){
      this->previous->next = NULL;
    }

    delete (Noh*)(data);
  };

};


int read_LCD_buttons()
{
  adc_key_in = analogRead(0);      // read the value from the sensor
  if (adc_key_in > 1000) return btnNONE; // We make this the 1st option for speed reasons since it will be the most likely result
  /*// For V1.1 us this threshold
  if (adc_key_in < 50)   return btnRIGHT;
  if (adc_key_in < 250)  return btnUP;
  if (adc_key_in < 450)  return btnDOWN;
  if (adc_key_in < 650)  return btnLEFT;
  if (adc_key_in < 850)  return btnSELECT;*/
  // For V1.0 comment the other threshold and use the one below:

  if (adc_key_in < 50)   return btnRIGHT;
  if (adc_key_in < 195)  return btnUP;
  if (adc_key_in < 380)  return btnDOWN;
  if (adc_key_in < 555)  return btnLEFT;
  if (adc_key_in < 790)  return btnSELECT;
/*
  char choice;
  cin >> choice;
  if (choice == 'u'){
    return btnUP;
  }
  else if (choice == 'd'){
    return btnDOWN;
  }
  else if (choice == 'l'){
    return btnLEFT;
  }
  else if (choice == 'r'){
    return btnRIGHT;
  }
  else if (choice == 's'){
    return btnSELECT;
  }*/
  return btnNONE;  // when all others fail, return this...
}

void print_menu(Noh* option){
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(option->asMenu()->name);
  lcd.setCursor(15, 0);
  lcd.print((char)(127)); // setinha
  if (option->next != NULL){
    lcd.setCursor(0, 1);
    lcd.print(option->next->asMenu()->name);
  }

/*
  cout << endl << endl << endl << endl << endl << endl << endl << (option->asMenu()->name);
  cout << (char)(0b01111111) << endl; // setinha
  if (option->next != NULL){
    cout << (option->next->asMenu()->name) << endl;
  }*/
}

void context_menu(Noh* option){
  bool in_context_page = true;
  Noh* last_page = option;
  print_menu(option);
  while (in_context_page){
    switch (read_LCD_buttons()){
      case btnNONE:
        break;
      case btnUP:
        // volta para a opção anterior
        if (option->previous != NULL){
          option = option->previous;
        }
        print_menu(option);
        while (read_LCD_buttons() == btnUP){
          delay(50);
        }
        break;
      case btnDOWN:
        // vai para a próxima opção
        if (option->next != NULL){
          option = option->next;
        }
        print_menu(option);
        while (read_LCD_buttons() == btnDOWN){
          delay(50);
        }
        break;
      case btnLEFT:
        // retorna para a página anterior
        in_context_page = false;
        delay(50);
        break;
      default:
        // seleciona a opção atual
        while (read_LCD_buttons() == btnRIGHT || read_LCD_buttons() == btnSELECT){
          delay(50);
        }
        last_page = option;
        option->asMenu()->select();
        while (read_LCD_buttons() == btnLEFT){
          delay(50);
        }
        option = last_page;
        print_menu(option);
    }
  }
}

void add_menu_option(Noh* node_above, Noh* node_to_be_inserted){
  if (node_above->previous == NULL && node_above->next == NULL){ // transforma o menu em uma lista circular
    node_above->previous = node_above;
    node_above->next = node_above;
  }
  node_to_be_inserted->previous = node_above;
  node_to_be_inserted->next = node_above->next;
  node_above->next = node_to_be_inserted;
  node_to_be_inserted->next->previous = node_to_be_inserted;
}

void add_submenu(Noh* node_father, Noh* node_to_be_inserted){
  node_father->asMenu()->leads_to_another_menu = true;
  node_father->asMenu()->data = node_to_be_inserted;
}


Noh* first_page = new Noh((void*)(new MenuOption((char*)"Trains")));


void setup(){
  lcd.begin(16, 2);
  Noh* aux = new Noh(new MenuOption((char*)"I like them!"));
  add_submenu(first_page, aux);
  Noh* aux2 = new Noh(new MenuOption((char*)"..."));
  add_menu_option(aux, aux2);
  aux2 = new Noh(new MenuOption((char*)"Fuooon"));
  add_menu_option(aux, aux2);
  aux = new Noh(new MenuOption((char*)"Muffin"));
  add_menu_option(first_page, aux);
  aux2 = new Noh(new MenuOption((char*)"I wanna die"));
  add_submenu(aux, aux2);
  aux = new Noh(new MenuOption((char*)":D"));
  add_menu_option(aux2, aux);
  aux = new Noh(new MenuOption((char*)"Stegosaurus"));
  add_menu_option(first_page, aux);
  aux = new Noh(new MenuOption((char*)"Real person"));
  add_menu_option(first_page, aux);
  aux2 = new Noh(new MenuOption((char*)"Skateboards"));
  add_submenu(aux, aux2);
}

void loop(){
  context_menu(first_page);
}