MicroDexed/UI.hpp

/*
   MicroDexed

   MicroDexed is a port of the Dexed sound engine
   (https://github.com/asb2m10/dexed) for the Teensy-3.5/3.6 with audio shield.
   Dexed ist heavily based on https://github.com/google/music-synthesizer-for-android

   (c)2018,2019 H. Wirtz <wirtz@parasitstudio.de>

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
*/

#ifdef ENABLE_LCD_UI
#ifndef _UI_HPP_
#define _UI_HPP_

#include "config.h"
#include "Disp_Plus.h"
#include "SoftenValue.hpp"
#include "effect_modulated_delay.h"
#include "effect_stereo_mono.h"
#include "dexed.h"

#include <LCDMenuLib2.h>
#include <Encoder.h>

#define _LCDML_DISP_cols  LCD_cols
#define _LCDML_DISP_rows  LCD_rows

#ifdef I2C_DISPLAY
#define _LCDML_DISP_cfg_cursor                     0x7E   // cursor Symbol
#else
#define _LCDML_DISP_cfg_cursor                     0x8d   // cursor Symbol
#endif
#define _LCDML_DISP_cfg_scrollbar                  1      // enable a scrollbar

extern config_t configuration;
extern void set_volume(uint8_t v, int8_t p, uint8_t m);
extern char bank_names[MAX_BANKS][BANK_NAME_LEN];
extern char bank_name[BANK_NAME_LEN];
extern char voice_name[VOICE_NAME_LEN];
extern char voice_names[MAX_VOICES][VOICE_NAME_LEN];
extern void strip_extension(char* s, char *target);
extern void eeprom_write(void);
extern bool get_voice_names_from_bank(uint8_t b);
extern bool load_sysex(uint8_t b, uint8_t v);
#ifdef DISPLAY_LCD_SPI
extern void change_disp_sd(bool d);
#endif
extern SoftenValue <uint8_t> soften_volume;
extern SoftenValue <uint8_t> soften_filter_res[NUM_DEXED];
extern SoftenValue <uint8_t> soften_filter_cut[NUM_DEXED];
extern AudioEffectDelay          delay1;
#ifdef USE_REVERB
extern AudioEffectFreeverbStereo freeverbs1;
#endif
extern AudioEffectModulatedDelay modchorus;
extern AudioSynthWaveform       modulator;
extern AudioMixer4              delay_fb_mixer;
extern AudioMixer4              master_mixer_r;
extern AudioMixer4              master_mixer_l;
extern AudioAmplifier           volume_r;
extern AudioAmplifier           volume_l;
extern AudioEffectStereoMono    stereomono1;
extern AudioSourceMicroDexed * MicroDexed[NUM_DEXED];

/***********************************************************************
   GLOBAL
************************************************************************/
elapsedMillis back_from_volume;

#ifdef I2C_DISPLAY
#include <LiquidCrystal_I2C.h>
Disp_Plus<LiquidCrystal_I2C> lcd(LCD_I2C_ADDRESS, _LCDML_DISP_cols, _LCDML_DISP_rows);
#endif

#ifdef U8X8_DISPLAY
#include <U8x8lib.h>
#ifdef U8X8_HAVE_HW_SPI
#include <SPI.h>
#endif
#ifdef U8X8_HAVE_HW_I2C
#include <Wire.h>
#endif
Disp_Plus<U8X8_DISPLAY_CLASS> lcd(/* cs=*/ U8X8_CS_PIN, /* dc=*/ U8X8_DC_PIN, /* reset=*/ U8X8_RESET_PIN);
//Disp_Plus<U8X8_DISPLAY_CLASS> lcd(U8X8_PIN_NONE);
#endif

const uint8_t scroll_bar[5][8] = {
  {B10001, B10001, B10001, B10001, B10001, B10001, B10001, B10001}, // scrollbar top
  {B11111, B11111, B10001, B10001, B10001, B10001, B10001, B10001}, // scroll state 1
  {B10001, B10001, B11111, B11111, B10001, B10001, B10001, B10001}, // scroll state 2
  {B10001, B10001, B10001, B10001, B11111, B11111, B10001, B10001}, // scroll state 3
  {B10001, B10001, B10001, B10001, B10001, B10001, B11111, B11111}  // scrollbar bottom
};

enum { ENC_R, ENC_L };
enum { MENU_START, MENU_VOICE, MENU_EDIT, MENU_VOLUME };
enum {MENU_VOICE_BANK, MENU_VOICE_SOUND};
uint8_t menu_state = MENU_START;
uint8_t menu_voice = MENU_VOICE_SOUND;
void lcdml_menu_display(void);
void lcdml_voice_menu_display(void);
void lcdml_menu_clear(void);
void lcdml_menu_control(void);
void encoder_right_up(void);
void encoder_right_down(void);
void encoder_right_button_long(void);
void encoder_right_button_short(void);
void encoder_left_up(void);
void encoder_left_down(void);
void encoder_left_button_long(void);
void encoder_left_button_short(void);
void lcdml_voice_menu_control(void);
void UI_func_sound(uint8_t param);
void UI_func_reverb_roomsize(uint8_t param);
void UI_func_reverb_damping(uint8_t param);
void UI_func_reverb_level(uint8_t param);
void UI_func_chorus_frequency(uint8_t param);
void UI_func_chorus_waveform(uint8_t param);
void UI_func_chorus_depth(uint8_t param);
void UI_func_chorus_level(uint8_t param);
void UI_func_delay_time(uint8_t param);
void UI_func_delay_feedback(uint8_t param);
void UI_func_delay_level(uint8_t param);
void UI_func_filter_cutoff(uint8_t param);
void UI_func_filter_resonance(uint8_t param);
void UI_func_midi_channel(uint8_t param);
void UI_func_loudness(uint8_t param);
void UI_func_panorama(uint8_t param);
void UI_func_stereo_mono(uint8_t param);
void UI_func_polyphony(uint8_t param);
void UI_func_engine(uint8_t param);
void UI_func_information(uint8_t param);
void UI_func_voice_selection(uint8_t param);
void UI_func_volume(uint8_t param);
void UI_function_not_enabled(void);
void lcd_display_int(int16_t var, uint8_t size, bool zeros, bool brackets, bool sign);
void lcd_display_float(float var, uint8_t size_number, uint8_t size_fraction, bool zeros, bool brackets, bool sign);

// normal menu
LCDMenuLib2_menu LCDML_0(255, 0, 0, NULL, NULL); // normal root menu element (do not change)
LCDMenuLib2 LCDML(LCDML_0, _LCDML_DISP_rows, _LCDML_DISP_cols, lcdml_menu_display, lcdml_menu_clear, lcdml_menu_control);

// LCDML_add(id, prev_layer, new_num, lang_char_array, callback_function)
LCDML_add(0, LCDML_0, 1, "Sound", UI_func_sound);
LCDML_add(1, LCDML_0, 2, "Effect", NULL);
LCDML_add(2, LCDML_0_2, 1, "Reverb", NULL);
LCDML_add(3, LCDML_0_2_1, 1, "Roomsize", UI_func_reverb_roomsize);
LCDML_add(4, LCDML_0_2_1, 2, "Damping", UI_func_reverb_damping);
LCDML_add(5, LCDML_0_2_1, 3, "Level", UI_func_reverb_level);
LCDML_add(6, LCDML_0_2, 2, "Chorus", NULL);
LCDML_add(7, LCDML_0_2_2, 1, "Frequency", UI_func_chorus_frequency);
LCDML_add(8, LCDML_0_2_2, 2, "Waveform", UI_func_chorus_waveform);
LCDML_add(9, LCDML_0_2_2, 3, "Depth", UI_func_chorus_depth);
LCDML_add(10, LCDML_0_2_2, 4, "Level", UI_func_chorus_level);
LCDML_add(11, LCDML_0_2, 3, "Delay", NULL);
LCDML_add(12, LCDML_0_2_3, 1, "Time", UI_func_delay_time);
LCDML_add(13, LCDML_0_2_3, 2, "Feedback", UI_func_delay_feedback);
LCDML_add(14, LCDML_0_2_3, 3, "Level", UI_func_delay_level);
LCDML_add(15, LCDML_0_2, 4, "Filter", NULL);
LCDML_add(16, LCDML_0_2_4, 1, "Cutoff", UI_func_filter_cutoff);
LCDML_add(17, LCDML_0_2_4, 2, "Resonance", UI_func_filter_resonance);
LCDML_add(18, LCDML_0, 3, "Store", NULL);
LCDML_add(19, LCDML_0, 4, "System", NULL);
LCDML_add(20, LCDML_0_4, 1, "MIDI Channel", UI_func_midi_channel);
LCDML_add(21, LCDML_0_4, 2, "Loudness", UI_func_loudness);
LCDML_add(22, LCDML_0_4, 3, "Panorama", UI_func_panorama);
LCDML_add(23, LCDML_0_4, 4, "Stereo/Mono", UI_func_stereo_mono);
LCDML_add(24, LCDML_0_4, 5, "Polyphony", UI_func_polyphony);
LCDML_add(25, LCDML_0_4, 6, "Engine", UI_func_engine);
LCDML_add(26, LCDML_0, 5, "Info", UI_func_information);
#define _LCDML_DISP_cnt 26

// create menu
LCDML_createMenu(_LCDML_DISP_cnt);

/***********************************************************************
   CONTROL
 ***********************************************************************/
#define g_LCDML_CONTROL_button_long_press LONG_BUTTON_PRESS
#define g_LCDML_CONTROL_button_short_press BUT_DEBOUNCE_MS

//#define ENCODER_OPTIMIZE_INTERRUPTS //Only when using pin2/3 (or 20/21 on mega)
Encoder ENCODER[NUM_ENCODER] = {Encoder(ENC_R_PIN_B, ENC_R_PIN_A), Encoder(ENC_L_PIN_B, ENC_L_PIN_A)};

long  g_LCDML_CONTROL_button_press_time[NUM_ENCODER] = {0, 0};
bool  g_LCDML_CONTROL_button_prev[NUM_ENCODER] = {HIGH, HIGH};
uint8_t g_LCDML_CONTROL_prev[NUM_ENCODER] = {0, 0};

#ifdef U8X8_DISPLAY
const uint8_t * flipped_scroll_bar[5];

uint8_t * rotTile(const uint8_t * tile) {
  uint8_t * newt = new uint8_t[8];
  for (int x = 0; x < 8; x++) {
    uint8_t newb = 0;
    for (int y = 0 ; y < 8; y++) {
      newb |= (tile[y] << x) & 0x80;
      newb >>= 1;
    }
    newt[x] = newb;
  }
  return newt;
}
#endif

void setup_ui(void) {
  // LCD Begin
#ifdef I2C_DISPLAY
  lcd.init();
  lcd.backlight();
  lcd.clear();
  lcd.blink_off();
  lcd.cursor_off();
  lcd.backlight();
#else
  lcd.begin();
  lcd.clear();
  lcd.setFont(u8x8_font_amstrad_cpc_extended_f);
#endif
  lcd.setCursor(1, 0);
  lcd.print(F("MicroDexed"));
  lcd.setCursor(0, 1);
  lcd.print(F("(c)parasiTstudio"));

#ifdef I2C_DISPLAY
  // set special chars for scrollbar
  lcd.createChar(0, (uint8_t*)scroll_bar[0]);
  lcd.createChar(1, (uint8_t*)scroll_bar[1]);
  lcd.createChar(2, (uint8_t*)scroll_bar[2]);
  lcd.createChar(3, (uint8_t*)scroll_bar[3]);
  lcd.createChar(4, (uint8_t*)scroll_bar[4]);
#else
  for (int x = 0; x < 5; x++) {
    flipped_scroll_bar[x] = rotTile(scroll_bar[x]);
  }
#endif

  // LCDMenuLib Setup
  LCDML_setup(_LCDML_DISP_cnt);
  // Enable Menu Rollover
  //LCDML.MENU_enRollover();
  // Enable Screensaver (screensaver menu function, time to activate in ms)
  //LCDML.SCREEN_enable(UI_func_voice_selection, VOICE_SELECTION_MS); // set to 10 seconds
}

void lcdml_menu_control(void)
{
  // If something must init, put in in the setup condition
  if (LCDML.BT_setup())
  {
    pinMode(BUT_R_PIN, INPUT_PULLUP);
    pinMode(BUT_L_PIN, INPUT_PULLUP);
  }

  if (back_from_volume > BACK_FROM_VOLUME_MS && menu_state == MENU_VOLUME)
  {
    UI_func_voice_selection(0);
    return;
  }

  //Volatile Variable
  long g_LCDML_CONTROL_Encoder_position[NUM_ENCODER] = {ENCODER[ENC_R].read(), ENCODER[ENC_L].read()};
  bool button[NUM_ENCODER] = {digitalRead(BUT_R_PIN), digitalRead(BUT_L_PIN)};

  /************************************************************************************
    Basic encoder handlying (from LCDMenuLib2
   ************************************************************************************/
  // RIGHT
  if (g_LCDML_CONTROL_Encoder_position[ENC_R] <= -3)
  {
    if (!button[ENC_R])
    {
      LCDML.BT_left();
      g_LCDML_CONTROL_button_prev[ENC_R] = LOW;
      g_LCDML_CONTROL_button_press_time[ENC_R] = -1;
    }
    else
    {
      encoder_right_up();
    }
    ENCODER[ENC_R].write(g_LCDML_CONTROL_Encoder_position[ENC_R] + 4);
  }
  else if (g_LCDML_CONTROL_Encoder_position[ENC_R] >= 3)
  {

    if (!button[ENC_R])
    {
      LCDML.BT_right();
      g_LCDML_CONTROL_button_prev[ENC_R] = LOW;
      g_LCDML_CONTROL_button_press_time[ENC_R] = -1;
    }
    else
    {
      encoder_right_down();
    }
    ENCODER[ENC_R].write(g_LCDML_CONTROL_Encoder_position[ENC_R] - 4);
  }
  else
  {
    if (!button[ENC_R] && g_LCDML_CONTROL_button_prev[ENC_R]) //falling edge, button[ENC_R] pressed
    {
      g_LCDML_CONTROL_button_prev[ENC_R] = LOW;
      g_LCDML_CONTROL_button_press_time[ENC_R] = millis();
    }
    else if (button[ENC_R] && !g_LCDML_CONTROL_button_prev[ENC_R]) //rising edge, button[ENC_R] not active
    {
      g_LCDML_CONTROL_button_prev[ENC_R] = HIGH;

      if (g_LCDML_CONTROL_button_press_time[ENC_R] < 0)
      {
        g_LCDML_CONTROL_button_press_time[ENC_R] = millis();
        //Reset for left right action
      }
      else if ((millis() - g_LCDML_CONTROL_button_press_time[ENC_R]) >= g_LCDML_CONTROL_button_long_press)
      {
        LCDML.BT_quit();
        if (menu_state == MENU_EDIT)
        {
          LCDML.BT_quit();
        }
        else if (menu_state == MENU_VOICE)
        {
          encoder_right_button_long();
        }
      }
      else if ((millis() - g_LCDML_CONTROL_button_press_time[ENC_R]) >= g_LCDML_CONTROL_button_short_press)
      {
        encoder_right_button_short();
      }
    }
  }
  // LEFT
  if (g_LCDML_CONTROL_Encoder_position[ENC_L] <= -3)
  {
    if (!button[ENC_L])
    {
      //LCDML.BT_left();
      g_LCDML_CONTROL_button_prev[ENC_L] = LOW;
      g_LCDML_CONTROL_button_press_time[ENC_L] = -1;
    }
    else
    {
      encoder_left_up();
    }
    ENCODER[ENC_L].write(g_LCDML_CONTROL_Encoder_position[ENC_L] + 4);
  }
  else if (g_LCDML_CONTROL_Encoder_position[ENC_L] >= 3)
  {

    if (!button[ENC_L])
    {
      //LCDML.BT_right();
      g_LCDML_CONTROL_button_prev[ENC_L] = LOW;
      g_LCDML_CONTROL_button_press_time[ENC_L] = -1;
    }
    else
    {
      encoder_left_down();
    }
    ENCODER[ENC_L].write(g_LCDML_CONTROL_Encoder_position[ENC_L] - 4);
  }
  else
  {
    if (!button[ENC_L] && g_LCDML_CONTROL_button_prev[ENC_L]) //falling edge, button[ENC_L] pressed
    {
      g_LCDML_CONTROL_button_prev[ENC_L] = LOW;
      g_LCDML_CONTROL_button_press_time[ENC_L] = millis();
    }
    else if (button[ENC_L] && !g_LCDML_CONTROL_button_prev[ENC_L]) //rising edge, button[ENC_L] not active
    {
      g_LCDML_CONTROL_button_prev[ENC_L] = HIGH;

      if (g_LCDML_CONTROL_button_press_time[ENC_L] < 0)
      {
        g_LCDML_CONTROL_button_press_time[ENC_L] = millis();
        //Reset for left right action
      }
      else if ((millis() - g_LCDML_CONTROL_button_press_time[ENC_L]) >= g_LCDML_CONTROL_button_long_press)
      {
        //LCDML.BT_quit();
        encoder_left_button_long();
      }
      else if ((millis() - g_LCDML_CONTROL_button_press_time[ENC_L]) >= g_LCDML_CONTROL_button_short_press)
      {
        //LCDML.BT_enter();
        encoder_left_button_short();
      }
    }
  }
}

/************************************************************************************
  RIGHT Encoder functions
 ************************************************************************************/
void encoder_right_up(void)
{
  switch (menu_state)
  {
    case MENU_EDIT:
    case MENU_VOLUME:
      menu_state = MENU_EDIT;
      LCDML.BT_down();
      break;
    case MENU_VOICE:
#ifdef DEBUG
      Serial.println(F("State: MENU_VOICE, Encoder left up"));
#endif
      switch (menu_voice)
      {
        case MENU_VOICE_BANK:
          if (configuration.bank < MAX_BANKS)
          {
            configuration.bank++;
#ifdef DISPLAY_LCD_SPI
            change_disp_sd(false);
#endif
            load_sysex(configuration.bank, configuration.voice);
            get_voice_names_from_bank(configuration.bank);
#ifdef DISPLAY_LCD_SPI
            change_disp_sd(true);
#endif

          }
          break;
        case MENU_VOICE_SOUND:
          if (configuration.voice < MAX_VOICES - 1)
            configuration.voice++;
          else
          {
            if (configuration.bank < MAX_BANKS)
            {
              configuration.bank++;
              configuration.voice = 0;
            }
          }
#ifdef DISPLAY_LCD_SPI
          change_disp_sd(false);
#endif
          load_sysex(configuration.bank, configuration.voice);
          get_voice_names_from_bank(configuration.bank);
#ifdef DISPLAY_LCD_SPI
          change_disp_sd(true);
#endif
          eeprom_write();

      }
      UI_func_voice_selection(0);
      break;
  }
}

void encoder_right_down(void)
{
  switch (menu_state)
  {
    case MENU_EDIT:
    case MENU_VOLUME:
      menu_state = MENU_EDIT;
      LCDML.BT_up();
      break;
    case MENU_VOICE:
#ifdef DEBUG
      Serial.println(F("State: MENU_VOICE, Encoder left down"));
#endif
      switch (menu_voice)
      {
        case MENU_VOICE_BANK:
          if (configuration.bank > 0)
          {
            configuration.bank--;
#ifdef DISPLAY_LCD_SPI
            change_disp_sd(false);
#endif

            load_sysex(configuration.bank, configuration.voice);
            get_voice_names_from_bank(configuration.bank);
#ifdef DISPLAY_LCD_SPI
            change_disp_sd(true);
#endif

          }
          break;
        case MENU_VOICE_SOUND:
          if (configuration.voice > 0)
            configuration.voice--;
          else
          {
            if (configuration.bank > 0)
            {
              configuration.bank--;
              configuration.voice = 31;
            }
          }
#ifdef DISPLAY_LCD_SPI
          change_disp_sd(false);
#endif
          load_sysex(configuration.bank, configuration.voice);
          get_voice_names_from_bank(configuration.bank);
#ifdef DISPLAY_LCD_SPI
          change_disp_sd(true);
#endif

          eeprom_write();
      }
      UI_func_voice_selection(0);
      break;
  }
}

void encoder_right_button_long(void)
{
#ifdef DEBUG
  Serial.println(F("State: MENU_VOICE, button long press"));
#else
  ;
#endif
}

void encoder_right_button_short(void)
{
#ifdef DEBUG
  Serial.println(F("Encoder right short press"));
#endif
  if (menu_state == MENU_EDIT)
  {
    LCDML.BT_enter();
  }
  else if (menu_state == MENU_VOICE)
  {
#ifdef DEBUG
    Serial.println(F("State: MENU_VOICE, button short press"));
#endif
    if (menu_voice == MENU_VOICE_BANK)
      menu_voice = MENU_VOICE_SOUND;
    else
      menu_voice = MENU_VOICE_BANK;
    UI_func_voice_selection(0);
  }
}

/************************************************************************************
  LEFT Encoder functions
 ************************************************************************************/
void encoder_left_up(void)
{
#ifdef DEBUG
  Serial.println(F("Volume +"));
#endif
  if (configuration.vol < VOLUME_MAX)
    soften_volume.update(soften_volume.value() + (VOLUME_MAX - VOLUME_MIN) / VOLUME_ENC_STEPS, SOFTEN_VALUE_CHANGE_STEPS);
  else
    configuration.vol = VOLUME_MAX;
  eeprom_write();
  UI_func_volume(0);
}

void encoder_left_down(void)
{
#ifdef DEBUG
  Serial.println(F("Volume -"));
#endif
  int8_t tmp = soften_volume.value() - (VOLUME_MAX - VOLUME_MIN) / VOLUME_ENC_STEPS;
  if (tmp > VOLUME_MIN)
    soften_volume.update(tmp, SOFTEN_VALUE_CHANGE_STEPS);
  else
    configuration.vol = VOLUME_MIN;
  eeprom_write();
  UI_func_volume(0);
}

void encoder_left_button_long(void)
{
#ifdef DEBUG
  Serial.println(F("Encoder left long press"));
#else
  ;
#endif
}

void encoder_left_button_short(void)
{
#ifdef DEBUG
  Serial.println(F("Encoder left short press"));
#endif
  if (menu_state == MENU_EDIT)
  {
    menu_state = MENU_VOICE;
    UI_func_voice_selection(0);
  }
  else if (menu_state == MENU_VOICE)
  {
    menu_state = MENU_EDIT;
    LCDML.MENU_goRoot();
  }
}

/***********************************************************************
   DISPLAY
 ***********************************************************************/
void lcdml_menu_clear(void)
{
  lcd.clear();
  lcd.setCursor(0, 0);
}

void lcdml_menu_display(void)
{
  // update content
  // ***************
  if (LCDML.DISP_checkMenuUpdate()) {
    // clear menu
    // ***************
    LCDML.DISP_clear();

    // declaration of some variables
    // ***************
    // content variable
    char content_text[_LCDML_DISP_cols];  // save the content text of every menu element
    // menu element object
    LCDMenuLib2_menu *tmp;
    // some limit values
    uint8_t i = LCDML.MENU_getScroll();
    uint8_t maxi = _LCDML_DISP_rows + i;
    uint8_t n = 0;

    // check if this element has children
    if ((tmp = LCDML.MENU_getDisplayedObj()) != NULL)
    {
      // loop to display lines
      do
      {
        // check if a menu element has a condition and if the condition be true
        if (tmp->checkCondition())
        {
          // check the type off a menu element
          if (tmp->checkType_menu() == true)
          {
            // display normal content
            LCDML_getContent(content_text, tmp->getID());
            lcd.setCursor(1, n);
            lcd.print(content_text);
          }
          else
          {
            if (tmp->checkType_dynParam()) {
              tmp->callback(n);
            }
          }
          // increment some values
          i++;
          n++;
        }
        // try to go to the next sibling and check the number of displayed rows
      } while (((tmp = tmp->getSibling(1)) != NULL) && (i < maxi));
    }
  }

  if (LCDML.DISP_checkMenuCursorUpdate())
  {
    // init vars
    uint8_t n_max             = (LCDML.MENU_getChilds() >= _LCDML_DISP_rows) ? _LCDML_DISP_rows : (LCDML.MENU_getChilds());
    uint8_t scrollbar_min     = 0;
    uint8_t scrollbar_max     = LCDML.MENU_getChilds();
    uint8_t scrollbar_cur_pos = LCDML.MENU_getCursorPosAbs();
    uint8_t scroll_pos        = ((1.*n_max * _LCDML_DISP_rows) / (scrollbar_max - 1) * scrollbar_cur_pos);

    // display rows
    for (uint8_t n = 0; n < n_max; n++)
    {
      //set cursor
      lcd.setCursor(0, n);

      //set cursor char
      if (n == LCDML.MENU_getCursorPos()) {
        lcd.write(_LCDML_DISP_cfg_cursor);
      } else {
        lcd.write(' ');
      }

      // delete or reset scrollbar
      if (_LCDML_DISP_cfg_scrollbar == 1) {
        if (scrollbar_max > n_max) {
#ifdef I2C_DISPLAY
          lcd.setCursor((_LCDML_DISP_cols - 1), n);
          lcd.write((uint8_t)0);
#else
          lcd.drawTile((_LCDML_DISP_cols - 1), n, 1, flipped_scroll_bar[0]);
          lcd.setCursor((_LCDML_DISP_cols), n + 1);
#endif
        }
        else {
          lcd.setCursor((_LCDML_DISP_cols - 1), n);
          lcd.print(F(" "));
        }
      }
    }

    // display scrollbar
    if (_LCDML_DISP_cfg_scrollbar == 1) {
      if (scrollbar_max > n_max) {
        //set scroll position
        if (scrollbar_cur_pos == scrollbar_min) {
          // min pos
#ifdef I2C_DISPLAY
          lcd.setCursor((_LCDML_DISP_cols - 1), 0);
          lcd.write((uint8_t)1);
#else
          lcd.drawTile((_LCDML_DISP_cols - 1), 0, 1, flipped_scroll_bar[1]);
          lcd.setCursor((_LCDML_DISP_cols), 1);
#endif
        } else if (scrollbar_cur_pos == (scrollbar_max - 1)) {
          // max pos
#ifdef I2C_DISPLAY
          lcd.setCursor((_LCDML_DISP_cols - 1), (n_max - 1));
          lcd.write((uint8_t)4);
#else
          lcd.drawTile((_LCDML_DISP_cols - 1), (n_max - 1), 1, flipped_scroll_bar[4]);
          lcd.setCursor((_LCDML_DISP_cols), (n_max));
#endif
        } else {
          // between
#ifdef I2C_DISPLAY
          lcd.setCursor((_LCDML_DISP_cols - 1), scroll_pos / n_max);
          lcd.write((uint8_t)(scroll_pos % n_max) + 1);
#else
          lcd.drawTile((_LCDML_DISP_cols - 1), scroll_pos / n_max, 1, flipped_scroll_bar[(scroll_pos % n_max) + 1]);
          lcd.setCursor((_LCDML_DISP_cols), (scroll_pos / n_max) + 1);
#endif
        }
      }
    }
  }
}

/***********************************************************************
   MENU
 ***********************************************************************/
void UI_func_sound(uint8_t param)
{
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("Sound"));
    lcd.setCursor(0, 1);
    lcd.print(F("not implemented"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter()) { // check if any button is pressed (enter, up, down, left, right)
      // LCDML_goToMenu stops a running menu function and goes to the menu
      LCDML.FUNC_goBackToMenu();
    }
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    eeprom_write();
  }
}

void UI_func_reverb_roomsize(uint8_t param)
{
#ifdef USE_REVERB
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("Reverb Roomsize"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter())
    {
      LCDML.FUNC_goBackToMenu();
    }
    else if (LCDML.BT_checkDown())
    {
      if (configuration.reverb_roomsize < REVERB_ROOMSIZE_MAX)
      {
        configuration.reverb_roomsize++;
      }
    }
    else if (LCDML.BT_checkUp())
    {
      if (configuration.reverb_roomsize > REVERB_ROOMSIZE_MIN)
      {
        configuration.reverb_roomsize--;
      }
    }

    lcd.setCursor(0, 1);
    lcd_display_int(configuration.reverb_roomsize, 3, true, true, false);

    freeverbs1.roomsize(configuration.reverb_roomsize / 100.0);
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
    eeprom_write();
  }
#else
  UI_function_not_enabled();
#endif
}

void UI_func_reverb_damping(uint8_t param)
{
#ifdef USE_REVERB
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("Reverb Damping"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter())
    {
      LCDML.FUNC_goBackToMenu();
    }
    else if (LCDML.BT_checkDown())
    {
      if (configuration.reverb_damping < REVERB_DAMPING_MAX)
      {
        configuration.reverb_damping++;
      }
    }
    else if (LCDML.BT_checkUp())
    {
      if (configuration.reverb_damping > REVERB_DAMPING_MIN)
      {
        configuration.reverb_damping--;
      }
    }

    lcd.setCursor(0, 1);
    lcd_display_int(configuration.reverb_damping, 3, true, true, false);

    freeverbs1.damping(configuration.reverb_damping / 100.0);
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
    eeprom_write();
  }
#else
  UI_function_not_enabled();
#endif
}

void UI_func_reverb_level(uint8_t param)
{
#ifdef USE_REVERB
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("Reverb Level"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter())
    {
      LCDML.FUNC_goBackToMenu();
    }
    else if (LCDML.BT_checkDown())
    {
      if (configuration.reverb_level < REVERB_LEVEL_MAX)
      {
        configuration.reverb_level++;
      }
    }
    else if (LCDML.BT_checkUp())
    {
      if (configuration.reverb_level > REVERB_LEVEL_MIN)
      {
        configuration.reverb_level--;

      }
    }

    lcd.setCursor(0, 1);
    lcd_display_int(configuration.reverb_level, 3, true, true, false);

    master_mixer_r.gain(1, configuration.reverb_level / 100.0);
    master_mixer_l.gain(1, configuration.reverb_level / 100.0);
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
    eeprom_write();
  }
#else
  UI_function_not_enabled();
#endif
}

void UI_func_chorus_frequency(uint8_t param)
{
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("Chorus Frequency"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter())
    {
      LCDML.FUNC_goBackToMenu();
    }
    else if (LCDML.BT_checkDown())
    {
      if (configuration.chorus_frequency < CHORUS_FREQUENCY_MAX)
      {
        configuration.chorus_frequency++;
      }
    }
    else if (LCDML.BT_checkUp())
    {
      if (configuration.chorus_frequency > CHORUS_FREQUENCY_MIN)
      {
        configuration.chorus_frequency--;
      }
    }

    lcd.setCursor(0, 1);
    lcd_display_float(configuration.chorus_frequency / 10.0, 2, 1, false, true, false);
    lcd.print(F(" Hz"));

    modulator.frequency(configuration.chorus_frequency / 10.0);
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
    eeprom_write();
  }
}

void UI_func_chorus_waveform(uint8_t param)
{
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("Chorus Waveform"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter())
    {
      LCDML.FUNC_goBackToMenu();
    }
    else if (LCDML.BT_checkDown())
    {
      if (configuration.chorus_waveform < CHORUS_WAVEFORM_MAX)
      {
        configuration.chorus_waveform++;
      }
    }
    else if (LCDML.BT_checkUp())
    {
      if (configuration.chorus_waveform > CHORUS_WAVEFORM_MIN)
      {
        configuration.chorus_waveform--;
      }
    }

    lcd.setCursor(0, 1);
    switch (configuration.chorus_waveform)
    {
      case 0:
        modulator.begin(WAVEFORM_TRIANGLE);
        lcd.print(F("[TRIANGLE]"));
        break;
      case 1:
        modulator.begin(WAVEFORM_SINE);
        lcd.print(F("[SINE    ]"));
        break;
      default:
        modulator.begin(WAVEFORM_TRIANGLE);
        lcd.print(F("[TRIANGLE]"));
        break;
    }
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
    eeprom_write();
  }
}

void UI_func_chorus_depth(uint8_t param)
{
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("Chorus Depth"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter())
    {
      LCDML.FUNC_goBackToMenu();
    }
    else if (LCDML.BT_checkDown())
    {
      if (configuration.chorus_depth < CHORUS_DEPTH_MAX)
      {
        configuration.chorus_depth++;
      }
    }
    else if (LCDML.BT_checkUp())
    {
      if (configuration.chorus_depth > CHORUS_DEPTH_MIN)
      {
        configuration.chorus_depth--;
      }
    }

    lcd.setCursor(0, 1);
    lcd_display_int(configuration.chorus_depth, 3, true, true, false);

    modulator.amplitude(configuration.chorus_depth / 100.0);
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
    eeprom_write();
  }
}

void UI_func_chorus_level(uint8_t param)
{
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("Chorus Level"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter())
    {
      LCDML.FUNC_goBackToMenu();
    }
    else if (LCDML.BT_checkDown())
    {
      if (configuration.chorus_level < CHORUS_LEVEL_MAX)
      {
        configuration.chorus_level++;
      }
    }
    else if (LCDML.BT_checkUp())
    {
      if (configuration.chorus_level > CHORUS_LEVEL_MIN)
      {
        configuration.chorus_level--;
      }
    }

    lcd.setCursor(0, 1);
    lcd_display_int(configuration.chorus_level, 3, true, true, false);

    master_mixer_r.gain(3, configuration.chorus_level / 100.0);
    master_mixer_l.gain(3, configuration.chorus_level / 100.0);
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
    eeprom_write();
  }
}

void UI_func_delay_time(uint8_t param)
{
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("Delay Time"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter())
    {
      LCDML.FUNC_goBackToMenu();
    }
    else if (LCDML.BT_checkDown())
    {
      if (configuration.delay_time < DELAY_TIME_MAX)
      {
        configuration.delay_time += 1;
      }
    }
    else if (LCDML.BT_checkUp())
    {
      if (configuration.delay_time > DELAY_TIME_MIN)
      {
        configuration.delay_time -= 1;
      }
    }

    lcd.setCursor(0, 1);
    lcd_display_int(configuration.delay_time * 10, 3, true, true, false);

    delay1.delay(0, configuration.delay_time * 10);
    lcd.print(F(" ms"));
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
    eeprom_write();
  }
}

void UI_func_delay_feedback(uint8_t param)
{
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("Delay Feedback"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter())
    {
      LCDML.FUNC_goBackToMenu();
    }
    else if (LCDML.BT_checkDown())
    {
      if (configuration.delay_feedback < DELAY_FEEDBACK_MAX)
      {
        configuration.delay_feedback++;
      }
    }
    else if (LCDML.BT_checkUp())
    {
      if (configuration.delay_feedback > DELAY_FEEDBACK_MIN)
      {
        configuration.delay_feedback--;
      }
    }

    lcd.setCursor(0, 1);
    lcd_display_int(configuration.delay_feedback, 3, true, true, false);

    delay_fb_mixer.gain(1, configuration.delay_feedback / 100.0 ); // amount of feedback
    delay_fb_mixer.gain(0, 1.0 - configuration.delay_feedback / 100.0); // original signal
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
    eeprom_write();
  }
}

void UI_func_delay_level(uint8_t param)
{
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("Delay Level"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter())
    {
      LCDML.FUNC_goBackToMenu();
    }
    else if (LCDML.BT_checkDown())
    {
      if (configuration.delay_level < DELAY_LEVEL_MAX)
      {
        configuration.delay_level++;
      }
    }
    else if (LCDML.BT_checkUp())
    {
      if (configuration.delay_level > DELAY_LEVEL_MIN)
      {
        configuration.delay_level--;
      }
    }

    lcd.setCursor(0, 1);
    lcd_display_int(configuration.delay_level, 3, true, true, false);

    master_mixer_r.gain(2, configuration.delay_level / 100.0);
    master_mixer_l.gain(2, configuration.delay_level / 100.0);
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
    eeprom_write();
  }
}

void UI_func_filter_cutoff(uint8_t param)
{
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("Filter Cut-Off"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter())
    {
      LCDML.FUNC_goBackToMenu();
    }
    else if (LCDML.BT_checkDown())
    {
      if (configuration.filter_cutoff < FILTER_CUTOFF_MAX)
      {
        configuration.filter_cutoff++;
      }
    }
    else if (LCDML.BT_checkUp())
    {
      if (configuration.filter_cutoff > FILTER_CUTOFF_MIN)
      {
        configuration.filter_cutoff--;
      }
    }

    lcd.setCursor(0, 1);
    lcd_display_int(configuration.filter_cutoff, 3, true, true, false);

    for (uint8_t i = 0; i < NUM_DEXED; i++)
    {
      MicroDexed[i]->fx.Cutoff = configuration.filter_cutoff / 100.0;
    }
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
    eeprom_write();
  }
}

void UI_func_filter_resonance(uint8_t param)
{
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("Filter Resonance"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter())
    {
      LCDML.FUNC_goBackToMenu();
    }
    else if (LCDML.BT_checkDown())
    {
      if (configuration.filter_resonance < FILTER_RESONANCE_MAX)
      {
        configuration.filter_resonance++;
      }
    }
    else if (LCDML.BT_checkUp())
    {
      if (configuration.filter_resonance > FILTER_RESONANCE_MIN)
      {
        configuration.filter_resonance--;
      }
    }

    lcd.setCursor(0, 1);
    lcd_display_int(configuration.filter_resonance, 3, true, true, false);

    for (uint8_t i = 0; i < NUM_DEXED; i++)
    {
      MicroDexed[i]->fx.Reso = configuration.filter_resonance / 100.0;
    }
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
    eeprom_write();
  }
}

void UI_func_midi_channel(uint8_t param)
{
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("MIDI Channel"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter())
    {
      LCDML.FUNC_goBackToMenu();
    }
    else if (LCDML.BT_checkDown())
    {
      if (configuration.midi_channel < MIDI_CHANNEL_MAX)
      {
        configuration.midi_channel++;
      }
    }
    else if (LCDML.BT_checkUp())
    {
      if (configuration.midi_channel > MIDI_CHANNEL_MIN)
      {
        configuration.midi_channel--;
      }
    }
    lcd.setCursor(0, 1);

    if (configuration.midi_channel == 0)
    {
      lcd.print(F("[OMNI]"));
    }
    else
    {
      lcd_display_int(configuration.midi_channel, 4, false, true, false);
    }
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
    eeprom_write();
  }
}

void UI_func_loudness(uint8_t param)
{
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("Loudness"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter())
    {
      LCDML.FUNC_goBackToMenu();
    }
    else if (LCDML.BT_checkDown())
    {
      if (configuration.loudness < LOUDNESS_MAX)
      {
        configuration.loudness++;
      }
    }
    else if (LCDML.BT_checkUp())
    {
      if (configuration.loudness > LOUDNESS_MIN)
      {
        configuration.loudness--;
      }
    }

    lcd.setCursor(0, 1);
    lcd_display_int(configuration.loudness, 3, true, true, false);

    for (uint8_t i = 0; i < NUM_DEXED; i++)
    {
      MicroDexed[i]->fx.Gain = configuration.loudness / 100.0;
    }
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
    eeprom_write();
  }
}

void UI_func_panorama(uint8_t param)
{
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("Panorama"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter())
    {
      LCDML.FUNC_goBackToMenu();
    }
    else if (LCDML.BT_checkDown())
    {
      if (configuration.pan < PANORAMA_MAX)
      {
        configuration.pan++;
      }
    }
    else if (LCDML.BT_checkUp())
    {
      if (configuration.pan > PANORAMA_MIN)
      {
        configuration.pan--;
      }
    }
    lcd.setCursor(0, 1);
    lcd_display_int(configuration.pan, 2, false, true, true);

    set_volume(configuration.vol, configuration.pan, configuration.mono);
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
    eeprom_write();
  }
}

void UI_func_stereo_mono(uint8_t param)
{
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("Stereo/Mono"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter())
    {
      LCDML.FUNC_goBackToMenu();
    }
    else if (LCDML.BT_checkDown())
    {
      if (configuration.mono < MONO_MAX)
      {
        configuration.mono++;
      }
    }
    else if (LCDML.BT_checkUp())
    {
      if (configuration.mono > MONO_MIN)
      {
        configuration.mono--;
      }
    }
    lcd.setCursor(0, 1);
    switch (configuration.mono)
    {
      case 0:
        lcd.print(F("[MONO  ]"));
        stereomono1.stereo(false);
        break;
      case 1:
        lcd.print(F("[STEREO]"));
        stereomono1.stereo(true);
        break;
      case 2:
        lcd.print(F("[MONO-R]"));
        stereomono1.stereo(false);
        break;
      case 3:
        lcd.print(F("[MONO-L]"));
        stereomono1.stereo(false);
        break;
    }
    set_volume(configuration.vol, configuration.pan, configuration.mono);
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
    eeprom_write();
  }
}

void UI_func_polyphony(uint8_t param)
{
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("Polyphony"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter())
    {
      LCDML.FUNC_goBackToMenu();
    }
    else if (LCDML.BT_checkDown())
    {
      if (configuration.polyphony < POLYPHONY_MAX)
      {
        configuration.polyphony++;
      }
    }
    else if (LCDML.BT_checkUp())
    {
      if (configuration.polyphony > POLYPHONY_MIN)
      {
        configuration.polyphony--;
      }
    }

    lcd.setCursor(0, 1);
    lcd_display_int(configuration.polyphony, 2, false, true, false);

    for (uint8_t i = 0; i < NUM_DEXED; i++)
    {
      MicroDexed[i]->setMaxNotes(configuration.polyphony);
    }
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
    eeprom_write();
  }
}

void UI_func_engine(uint8_t param)
{
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("Engine"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter())
    {
      LCDML.FUNC_goBackToMenu();
    }
    else if (LCDML.BT_checkDown())
    {
      if (configuration.engine < ENGINE_MAX)
      {
        configuration.engine++;
      }
    }
    else if (LCDML.BT_checkUp())
    {
      if (configuration.engine > ENGINE_MIN)
      {
        configuration.engine--;
      }
    }

    lcd.setCursor(0, 1);
    switch (configuration.engine)
    {
      case 0:
        lcd.print(F("[MODERN]"));
        break;
      case 1:
        lcd.print(F("[MARK 1 ]"));
        break;
      case 2:
        lcd.print(F("[OPL    ]"));
        break;
    }

    for (uint8_t i = 0; i < NUM_DEXED; i++)
    {
      MicroDexed[i]->setEngineType(configuration.engine);
    }
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
    eeprom_write();
  }
}

void UI_func_information(uint8_t param)
{
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("MicroDexed"));
    lcd.setCursor(0, 1);
    lcd.print(VERSION);
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    // loop function, can be run in a loop when LCDML_DISP_triggerMenu(xx) is set
    // the quit button works in every DISP function without any checks; it starts the loop_end function
    if (LCDML.BT_checkEnter()) { // check if any button is pressed (enter, up, down, left, right)
      // LCDML_goToMenu stops a running menu function and goes to the menu
      LCDML.FUNC_goBackToMenu();
    }
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
  }
}

void UI_func_voice_selection(uint8_t param)
{
#ifdef DEBUG
  Serial.println(F("UI_func_voice_selection()"));
#endif

  menu_state = MENU_VOICE;

  strip_extension(bank_names[configuration.bank], bank_name);

  //LCDML.DISP_clear();

  // display bank and voice number
  lcd.show(0, 0, 2, configuration.bank);
  lcd.show(1, 0, 2, configuration.voice + 1);

  // display names
  lcd.show(0, 4, 10, bank_name);
  lcd.show(1, 4, 10, voice_names[configuration.voice]);

  // display selections
  switch (menu_voice)
  {
    case MENU_VOICE_BANK:
      lcd.show(0, 2, 2, " [");
      lcd.show(0, 14, 2, "] ");
      lcd.show(1, 2, 2, "  ");
      lcd.show(1, 14, 2, "  ");
      break;
    case MENU_VOICE_SOUND:
      lcd.show(0, 2, 2, "  ");
      lcd.show(0, 14, 2, "  ");
      lcd.show(1, 2, 2, " [");
      lcd.show(1, 14, 2, "] ");
      break;
  }
  for (int x = 2; x < LCD_rows; x++) {
    lcd.show(x, 0, LCD_cols + 1, " ");
  }
}

void UI_func_volume(uint8_t param)
{
#ifdef DEBUG
  Serial.println(F("UI_func_volume()"));
#endif

  menu_state = MENU_VOLUME;
  back_from_volume = 0;

  // update LCD content
  LCDML.DISP_clear();
  lcd.show(0, 0, 8, "Volume: ");
  lcd.show(0, 9, 3, configuration.vol);
  lcd.setCursor(1, 1);
  for (uint8_t i = 0; i < LCD_cols; i++)
  {
    if (i < int((LCD_cols - 2) * configuration.vol / 100.0))
      lcd.print(F("*"));
    else
      lcd.print(F(" "));
  }
  set_volume(configuration.vol, configuration.pan, configuration.mono);
  lcd.show(1, 0, 1, "[");
  lcd.show(1, 15, 1, "]");
}

void UI_function_not_enabled(void)
{
  if (LCDML.FUNC_setup())         // ****** SETUP *********
  {
    // setup function
    lcd.setCursor(0, 0);
    lcd.print(F("Function not"));
    lcd.setCursor(0, 1);
    lcd.print(F("enabled!"));
  }

  if (LCDML.FUNC_loop())          // ****** LOOP *********
  {
    if (LCDML.BT_checkEnter())
    {
      LCDML.FUNC_goBackToMenu();
    }
  }

  if (LCDML.FUNC_close())     // ****** STABLE END *********
  {
    // you can here reset some global vars or do nothing
  }
}

void lcd_display_int(int16_t var, uint8_t size, bool zeros, bool brackets, bool sign)
{
  int16_t tmp = 0;
  uint16_t p;
  bool non_zero_found = false;

  if (size < 1)
    return;

  if (brackets == true)
    lcd.print(F("["));

  if (sign == true)
  {
    size++;
    if (var < 0)
    {
      lcd.print(F("-"));
      var = abs(var);
    }
    else if (var > 0)
      lcd.print(F("+"));
    else
      lcd.print(F(" "));
  }

  for (int8_t i = size - 1 ; i >= 0; i--)
  {
    p = int(pow(10, i));
    tmp = int(var / p);

    if (tmp == 0)
    {
      if (zeros == true)
        lcd.print(F("0"));
      else
      {
        if (non_zero_found == true)
          lcd.print(F("0"));
        else
          lcd.print(F(" "));
      }
    }
    else
    {
      non_zero_found = true;
      lcd.print(tmp);
    }
    var -= (tmp * p);
  }

  if (brackets == true)
    lcd.print(F("]"));
}

void lcd_display_float(float var, uint8_t size_number, uint8_t size_fraction, bool zeros, bool brackets, bool sign)
{
  float fraction;
  float number;

  if (size_number < 1 || size_fraction < 1)
    return;

  fraction = modff(var, &number);

  if (brackets == true)
    lcd.print(F("["));

  if (int(number) == 0)
  {
    if (zeros == true)
      lcd.print(F("00"));
    else
      lcd.print(F(" 0"));
  }
  else
    lcd_display_int(int(number), size_number, zeros, false, sign);
  lcd.print(F("."));
  lcd_display_int(round(fraction * pow(10, size_fraction)), size_fraction, true, false, false);

  if (brackets == true)
    lcd.print(F("]"));
}
#endif
#endif