refactor(simu): use SDL & ImGui (#6233)

Co-authored-by: raphaelcoeffic <1050031+raphaelcoeffic@users.noreply.github.com> Co-authored-by: Malte Langermann <malte@langermann.net>
2025-07-20 11:30:05 +02:00
parent 14287cb91d
commit 4eddda034d
46 changed files with 2136 additions and 1577 deletions
@@ -0,0 +1,26 @@
+# Fetch imgui source code from Github
+
+include(FetchContent)
+
+FetchContent_Declare(
+  imgui
+  GIT_REPOSITORY https://github.com/ocornut/imgui
+  GIT_TAG        dbb5eeaadffb6a3ba6a60de1290312e5802dba5a # v1.91.8
+  SOURCE_DIR     imgui
+)
+
+FetchContent_MakeAvailable(imgui)
+
+add_library(imgui STATIC
+  imgui/imgui.cpp
+  imgui/imgui_draw.cpp
+  imgui/imgui_tables.cpp
+  imgui/imgui_widgets.cpp
+  imgui/backends/imgui_impl_sdl2.cpp
+  imgui/backends/imgui_impl_sdlrenderer2.cpp
+)
+
+target_include_directories(imgui PUBLIC
+  ${CMAKE_CURRENT_BINARY_DIR}/imgui
+  ${CMAKE_CURRENT_BINARY_DIR}/imgui/backends
+)
@@ -1,63 +0,0 @@
-# Imported from the DeskVox project (LPGL 2.1)
-
-include(FindPackageHandleStandardArgs)
-
-set(hints
-  $ENV{LIB_BASE_PATH}/fox
-)
-
-set(paths
-  /usr
-  /usr/local
-)
-
-find_path(FOX_INCLUDE_DIR
-  NAMES
-    fx.h
-  HINTS
-    ${hints}
-  PATHS
-    ${paths}
-  PATH_SUFFIXES
-    include
-    include/fox
-    include/fox-1.6
-)
-
-find_library(FOX_LIBRARY
-  NAMES
-    FOX-1.6
-    fox-1.6
-  HINTS
-    ${hints}
-  PATHS
-    ${paths}
-  PATH_SUFFIXES
-    lib64
-    lib
-)
-
-find_library(FOX_LIBRARY_DEBUG
-  NAMES
-    FOXD-1.6
-    foxd-1.6
-  HINTS
-    ${hints}
-  PATHS
-    ${paths}
-  PATH_SUFFIXES
-    lib64
-    lib
-)
-
-if(FOX_LIBRARY_DEBUG)
-  set(FOX_LIBRARIES optimized ${FOX_LIBRARY} debug ${FOX_LIBRARY_DEBUG})
-else()
-  set(FOX_LIBRARIES ${FOX_LIBRARY})
-endif()
-
-find_package_handle_standard_args(Fox
-  DEFAULT_MSG
-  FOX_INCLUDE_DIR
-  FOX_LIBRARY
-)
@@ -1,71 +0,0 @@
-# Find libphonon
-# Once done this will define
-#
-#  PHONON_FOUND    - system has Phonon Library
-#  PHONON_INCLUDES - the Phonon include directory
-#  PHONON_LIBS     - link these to use Phonon
-#  PHONON_VERSION  - the version of the Phonon Library
-
-# Copyright (c) 2008, Matthias Kretz <kretz@kde.org>
-#
-# Redistribution and use is allowed according to the terms of the BSD license.
-# For details see the accompanying COPYING-CMAKE-SCRIPTS file.
-
-macro(_phonon_find_version)
-   set(_phonon_namespace_header_file "${PHONON_INCLUDE_DIR}/phonon/phononnamespace.h")
-   if (APPLE AND EXISTS "${PHONON_INCLUDE_DIR}/Headers/phononnamespace.h")
-      set(_phonon_namespace_header_file "${PHONON_INCLUDE_DIR}/Headers/phononnamespace.h")
-   endif (APPLE AND EXISTS "${PHONON_INCLUDE_DIR}/Headers/phononnamespace.h")
-   file(READ ${_phonon_namespace_header_file} _phonon_header LIMIT 5000 OFFSET 1000)
-   string(REGEX MATCH "define PHONON_VERSION_STR \"(4\\.[0-9]+\\.[0-9a-z]+)\"" _phonon_version_match "${_phonon_header}")
-   set(PHONON_VERSION "${CMAKE_MATCH_1}")
-   message(STATUS "Phonon Version: ${PHONON_VERSION}")
-endmacro(_phonon_find_version)
-
-if(PHONON_FOUND)
-   # Already found, nothing more to do except figuring out the version
-   _phonon_find_version()
-else(PHONON_FOUND)
-   if(PHONON_INCLUDE_DIR AND PHONON_LIBRARY)
-      set(PHONON_FIND_QUIETLY TRUE)
-   endif(PHONON_INCLUDE_DIR AND PHONON_LIBRARY)
-
-   # As discussed on kde-buildsystem: first look at CMAKE_PREFIX_PATH, then at the suggested PATHS (kde4 install dir)
-   find_library(PHONON_LIBRARY NAMES phonon phonon4 PATHS ${KDE4_LIB_INSTALL_DIR} ${QT_LIBRARY_DIR} NO_SYSTEM_ENVIRONMENT_PATH NO_CMAKE_SYSTEM_PATH)
-   # then at the default system locations (CMAKE_SYSTEM_PREFIX_PATH, i.e. /usr etc.)
-   find_library(PHONON_LIBRARY NAMES phonon)
-
-   find_path(PHONON_INCLUDE_DIR NAMES phonon/phonon_export.h PATHS ${KDE4_INCLUDE_INSTALL_DIR} ${QT_INCLUDE_DIR} ${INCLUDE_INSTALL_DIR} ${QT_LIBRARY_DIR} NO_SYSTEM_ENVIRONMENT_PATH NO_CMAKE_SYSTEM_PATH)
-   find_path(PHONON_INCLUDE_DIR NAMES phonon/phonon_export.h)
-
-   if(PHONON_INCLUDE_DIR AND PHONON_LIBRARY)
-      set(PHONON_LIBS ${phonon_LIB_DEPENDS} ${PHONON_LIBRARY})
-      set(PHONON_INCLUDES ${PHONON_INCLUDE_DIR}/KDE ${PHONON_INCLUDE_DIR})
-      set(PHONON_FOUND TRUE)
-      _phonon_find_version()
-   else(PHONON_INCLUDE_DIR AND PHONON_LIBRARY)
-      set(PHONON_FOUND FALSE)
-   endif(PHONON_INCLUDE_DIR AND PHONON_LIBRARY)
-
-   if(PHONON_FOUND)
-      if(NOT PHONON_FIND_QUIETLY)
-         message(STATUS "Found Phonon: ${PHONON_LIBRARY}")
-         message(STATUS "Found Phonon Includes: ${PHONON_INCLUDES}")
-      endif(NOT PHONON_FIND_QUIETLY)
-   else(PHONON_FOUND)
-      if(Phonon_FIND_REQUIRED)
-         if(NOT PHONON_INCLUDE_DIR)
-            message(STATUS "Phonon includes NOT found!")
-         endif(NOT PHONON_INCLUDE_DIR)
-         if(NOT PHONON_LIBRARY)
-            message(STATUS "Phonon library NOT found!")
-         endif(NOT PHONON_LIBRARY)
-         message(FATAL_ERROR "Phonon library or includes NOT found!")
-      else(Phonon_FIND_REQUIRED)
-         message(STATUS "Unable to find Phonon")
-      endif(Phonon_FIND_REQUIRED)
-   endif(PHONON_FOUND)
-
-
-   mark_as_advanced(PHONON_INCLUDE_DIR PHONON_LIBRARY PHONON_INCLUDES)
-endif(PHONON_FOUND)
@@ -1,68 +0,0 @@
-# Find Xerces-C
-# The following setings are defined
-# XERCESC_ROOT_DIR, the root of the include and lib directory
-# XERCESC_INCLUDE_DIR, the full path of the include dir (ADVANCED)
-# XERCESC_LIBRARIES, the name of the xerces-c library (ADVANCED)
-
-# Look for a root installation
-IF( MSVC )
-SET( XERCES_WINDIR C:/Programs/xerces-vc )
-ELSE( )
-SET( XERCES_WINDIR C:/Programs/xerces )
-ENDIF( )
-
-FIND_PATH(XERCESC_ROOT_DIR include/xercesc/parsers/SAXParser.hpp
-  ${XERCES_WINDIR}
-  "C:/mingw/msys/1.0/local"
-  "C:/Program Files/CodeSynthesis XSD 3.2"
-  /usr
-  /usr/local
-  "C:/MinGW"
-  $ENV{CODESYNTH}
-  DOC "The root of an installed xerces-c installation"
-)
-
-# try to find the header
-FIND_PATH(XERCESC_INCLUDE_DIR xercesc/parsers/SAXParser.hpp
-  ${XERCESC_ROOT_DIR}/include
-  /usr/include
-  /usr/local/include
-)
-
-# Find the library
-FIND_LIBRARY(XERCESC_LIBRARY
-  NAMES xerces-c xerces-c_3
-  PATHS
-    ${XERCESC_ROOT_DIR}/lib
-    ${XERCESC_ROOT_DIR}/lib/vc-9.0
-    ${XERCESC_ROOT_DIR}/lib64/vc-9.0
-    /usr/lib
-    /usr/local/lib
-  DOC "The name of the xerces-c library"
-)
-
-IF (XERCESC_ROOT_DIR)
-  IF (XERCESC_INCLUDE_DIR AND XERCESC_LIBRARY)
-    SET (XERCESC_FOUND TRUE)
-    SET (XERCESC_LIBRARIES "${XERCESC_LIBRARY}")
-    # FIXME: There should be a better way of handling this?
-    # FIXME: How can we test to see if the lib dir isn't
-    # FIXME: one of the default dirs?
-    LINK_DIRECTORIES(${XERCESC_ROOT_DIR}/lib)
-  ENDIF (XERCESC_INCLUDE_DIR AND XERCESC_LIBRARY)
-ENDIF (XERCESC_ROOT_DIR)
-
-IF (XERCESC_FOUND)
-  IF (NOT XERCESC_FIND_QUIETLY)
-    MESSAGE (STATUS "  found xerces-c: ${XERCESC_LIBRARY}")
-  ENDIF (NOT XERCESC_FIND_QUIETLY)
-ELSE (XERCESC_FOUND)
-  IF (XERCESC_FIND_REQUIRED)
-    MESSAGE(FATAL_ERROR "Could not find Xerces-C")
-  ENDIF (XERCESC_FIND_REQUIRED)
-ENDIF (XERCESC_FOUND)
-
-MARK_AS_ADVANCED(
-  XERCESC_INCLUDE_DIR
-  XERCESC_LIBRARY
-)
@@ -1,54 +0,0 @@
-# Locate Xsd from code synthesis include paths and binary
-# Xsd can be found at http://codesynthesis.com/products/xsd/
-# Written by Frederic Heem, frederic.heem _at_ telsey.it
-
-# This module defines
-# XSD_INCLUDE_DIR, where to find elements.hxx, etc.
-# XSD_EXECUTABLE, where is the xsd compiler
-# XSD_FOUND, If false, don't try to use xsd
-
-FIND_PATH( XSD_INCLUDE_DIR xsd/cxx/parser/elements.hxx
-  "/opt/local/xsd-3.3.0-i686-macosx/libxsd"
-  "C:/Programs/xsd-3.3.0/libxsd"
-  "C:/Program Files/CodeSynthesis XSD 3.2/include"
-  "C:/mingw/xsd-3.3.0-i686-windows/libxsd"
-  $ENV{XSDDIR}/include
-  $ENV{CODESYNTH}/include
-  /usr/local/include /usr/include
-  $ENV{XSDDIR}/libxsd
-)
-
-IF( WIN32 )
-  SET( XSDCXX_FILENAME1 xsd-cxx.exe )
-ELSE( )
-  SET( XSDCXX_FILENAME1 xsdcxx )
-  SET( XSDCXX_FILENAME2 xsd )
-ENDIF( )
-
-FIND_PROGRAM( XSDCXX_EXECUTABLE
-  NAMES
-    ${XSDCXX_FILENAME1} ${XSDCXX_FILENAME2}
-  PATHS
-    "/opt/local/xsd-3.3.0-i686-macosx/bin"
-    "C:/Programs/xsd-3.3.0/bin"
-    "C:/mingw/xsd-3.3.0-i686-windows/bin"
-    "C:/Program Files/CodeSynthesis XSD 3.2/bin"
-    $ENV{XSDDIR}/bin
-    /usr/local/bin
-    /usr/bin
-    $ENV{XSDDIR}/xsd
-)
-
-MESSAGE(STATUS ${XSDCXX_EXECUTABLE})
-
-# if the include and the program are found then we have it
-IF( XSD_INCLUDE_DIR )
-  IF( XSDCXX_EXECUTABLE )
-    SET( XSD_FOUND "YES" )
-  ENDIF( XSDCXX_EXECUTABLE )
-ENDIF( XSD_INCLUDE_DIR )
-
-MARK_AS_ADVANCED(
-  XSD_INCLUDE_DIR
-  XSDCXX_EXECUTABLE
-)
@@ -28,6 +28,7 @@ endif()

 set(CMAKE_COLOR_MAKEFILE ON)
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+set(CMAKE_CXX_STANDARD 17)

 add_definitions(-D_GLIBCXX_USE_C99=1) # proper to_string definition

@@ -1,41 +1,27 @@

 option(DISABLE_COMPANION "Disable building companion and simulators" OFF)

-# if(WIN32)
-#   set(WIN_EXTRA_LIBS_PATH "C:/Programs" CACHE PATH
-#     "Base path to extra libs/headers on Windows (SDL & pthreads folders should be in here).")
-#   list(APPEND CMAKE_PREFIX_PATH "${WIN_EXTRA_LIBS_PATH}" "${WIN_EXTRA_LIBS_PATH}/SDL")  # hints for FindSDL
-# endif()
-
-# libfox
-find_package(Fox QUIET)  # QUIET not working on WIN32?
-if (FOX_FOUND)
-  message(STATUS "Foxlib found at ${FOX_LIBRARY}")
-else()
-  message("Libfox not found, simu target will not be available")
-endif()
-
 if(NOT DISABLE_COMPANION)
  include(QtDefs)
 endif(NOT DISABLE_COMPANION)

-if(Qt5Core_FOUND OR FOX_FOUND)
-  set(SDL2_BUILDING_LIBRARY YES)  # this prevents FindSDL from appending SDLmain lib to the results, which we don't want
-  find_package("SDL2")
-  if(SDL2_FOUND)
-    # find_package("SDL2") does not set a variable holding the path to the location of the SDL2 shared library
-    find_file(SDL2_LIB_PATH
-              NAMES
-                libSDL2.so
-                SDL2.dll
-                SDL2.dylib
-              HINTS
-                "/usr/lib/x86_64-linux-gnu"
-                ${SDL2_LIBRARY_PATH})
-    message(STATUS "SDL2 Lib: ${SDL2_LIB_PATH} Libs: ${SDL2_LIBRARIES}; Headers: ${SDL2_INCLUDE_DIRS}")
-  else()
-    message(STATUS "SDL2 not found! Simulator audio, and joystick inputs, will not work.")
-  endif()
+# this prevents FindSDL from appending SDLmain lib to the results, which we don't want
+set(SDL2_BUILDING_LIBRARY YES)
+find_package("SDL2")
+
+if(SDL2_FOUND)
+  # find_package("SDL2") does not set a variable holding the path to the location of the SDL2 shared library
+  find_file(SDL2_LIB_PATH
+            NAMES
+              libSDL2.so
+              SDL2.dll
+              SDL2.dylib
+            HINTS
+              "/usr/lib/x86_64-linux-gnu"
+              ${SDL2_LIBRARY_PATH})
+  message(STATUS "SDL2 Lib: ${SDL2_LIB_PATH} Libs: ${SDL2_LIBRARIES}; Headers: ${SDL2_INCLUDE_DIRS}")
+else()
+  message(STATUS "SDL not found! Simulator audio, and joystick inputs, will not work.")
 endif()

 if(Qt5Core_FOUND AND NOT DISABLE_COMPANION)
@@ -6,14 +6,14 @@ endif()
 set(CMAKE_AUTOMOC ON)
 set(CMAKE_AUTOUIC ON)

-find_package(Qt5Core)
-find_package(Qt5Widgets)
-find_package(Qt5Xml)
-find_package(Qt5LinguistTools)
-find_package(Qt5PrintSupport)
-find_package(Qt5Multimedia)
-find_package(Qt5Svg)
-find_package(Qt5SerialPort)
+find_package(Qt5Core QUIET)
+find_package(Qt5Widgets QUIET)
+find_package(Qt5Xml QUIET)
+find_package(Qt5LinguistTools QUIET)
+find_package(Qt5PrintSupport QUIET)
+find_package(Qt5Multimedia QUIET)
+find_package(Qt5Svg QUIET)
+find_package(Qt5SerialPort QUIET)

 if(Qt5Core_FOUND)
  message(STATUS "Qt Version: ${Qt5Core_VERSION}")
@@ -28,9 +28,6 @@ option(SEMIHOSTING "Enable debugger semihosting" OFF)
 option(JITTER_MEASURE "Enable ADC jitter measurement" OFF)
 option(WATCHDOG "Enable hardware Watchdog" ON)
 option(ASTERISK "Enable asterisk icon (test only firmware)" OFF)
-if(SDL2_FOUND)
-  option(SIMU_AUDIO "Enable simulator audio." ON)
-endif()
 option(LUA "Enable LUA support" ON)
 option(SIMU_DISKIO "Enable disk IO simulation in simulator. Simulator will use FatFs module and simulated IO layer that  uses \"./sdcard.image\" file as image of SD card. This file must contain whole SD card from first to last sector" OFF)
 option(SIMU_LUA_COMPILER "Pre-compile and save Lua scripts in simulator." ON)
@@ -245,10 +242,6 @@ if(WATCHDOG AND NOT NATIVE_BUILD)
  add_definitions(-DUSE_WATCHDOG)
 endif()

-if(SIMU_AUDIO)
-  add_definitions(-DSIMU_AUDIO)
-endif()
-
 if(SIMU_DISKIO)
  add_definitions(-DSIMU_DISKIO)
 endif()
@@ -493,10 +486,6 @@ endif()

 if(NATIVE_BUILD)
  set(RADIOLIB_NATIVE_SRC ${SRC})
-  if(SIMU_DISKIO)
-    set(RADIOLIB_NATIVE_SRC ${RADIOLIB_NATIVE_SRC}
-      ${FATFS_DIR}/ff.c ${FATFS_DIR}/ffunicode.c)
-  endif()

  # Pack all radio sources into an object lib
  add_library(radiolib_native OBJECT EXCLUDE_FROM_ALL
@@ -370,6 +370,17 @@ AudioQueue::AudioQueue()

 #define CODEC_ID_PCM_S16LE  1

+
+static void _audio_lock()
+{
+  mutex_lock(&audioMutex);
+}
+
+static void _audio_unlock()
+{
+  mutex_unlock(&audioMutex);
+}
+
 #if !defined(__SSAT)
  #define _sat_s16(x) ((int16_t)limit<int32_t>(INT16_MIN, (x), INT16_MAX))
 #else
@@ -613,9 +624,9 @@ void AudioQueue::wakeup()

    // mix the normal context (tones and wavs)
    if (normalContext.isEmpty() && !fragmentsFifo.empty()) {
-      mutex_lock(&audioMutex);
+      _audio_lock();
      normalContext.setFragment(fragmentsFifo.get());
-      mutex_unlock(&audioMutex);
+      _audio_unlock();
    }
    result = normalContext.mixBuffer(buffer, g_eeGeneral.beepVolume, g_eeGeneral.wavVolume, fade);
    if (result > 0) {
@@ -696,10 +707,11 @@ bool AudioQueue::isPlaying(uint8_t id)
 void AudioQueue::playTone(uint16_t freq, uint16_t len, uint16_t pause, uint8_t flags, int8_t freqIncr, int8_t fragmentVolume)
 {
 #if defined(SIMU) && !defined(SIMU_AUDIO)
+  #warning "NO audio"
  return;
 #endif

-  mutex_lock(&audioMutex);
+  _audio_lock();

  freq = limit<uint16_t>(BEEP_MIN_FREQ, freq, BEEP_MAX_FREQ);

@@ -722,7 +734,7 @@ void AudioQueue::playTone(uint16_t freq, uint16_t len, uint16_t pause, uint8_t f
    }
  }

-  mutex_unlock(&audioMutex);
+  _audio_unlock();
 }

 void AudioQueue::playFile(const char * filename, uint8_t flags, uint8_t id, int8_t fragmentVolume)
@@ -745,7 +757,7 @@ void AudioQueue::playFile(const char * filename, uint8_t flags, uint8_t id, int8
    return;
  }

-  mutex_lock(&audioMutex);
+  _audio_lock();

  if (flags & PLAY_BACKGROUND) {
    backgroundContext.clear();
@@ -755,7 +767,7 @@ void AudioQueue::playFile(const char * filename, uint8_t flags, uint8_t id, int8
    fragmentsFifo.push(AudioFragment(filename, flags & 0x0f, fragmentVolume, id));
  }

-  mutex_unlock(&audioMutex);
+  _audio_unlock();
 }

 void AudioQueue::stopPlay(uint8_t id)
@@ -768,12 +780,12 @@ void AudioQueue::stopPlay(uint8_t id)
  return;
 #endif

-  mutex_lock(&audioMutex);
+  _audio_lock();

  fragmentsFifo.removePromptById(id);
  backgroundContext.stop(id);

-  mutex_unlock(&audioMutex);
+  _audio_unlock();
 }

 void AudioQueue::stopSD()
@@ -786,19 +798,19 @@ void AudioQueue::stopSD()
 void AudioQueue::stopAll()
 {
  flush();
-  mutex_lock(&audioMutex);
+  _audio_lock();
  priorityContext.clear();
  normalContext.clear();
-  mutex_unlock(&audioMutex);
+  _audio_unlock();
 }

 void AudioQueue::flush()
 {
-  mutex_lock(&audioMutex);
+  _audio_lock();
  fragmentsFifo.clear();
  varioContext.clear();
  backgroundContext.clear();
-  mutex_unlock(&audioMutex);
+  _audio_unlock();
 }

 void audioPlay(unsigned int index, uint8_t id)
@@ -469,7 +469,6 @@ enum {
 void codecsInit();
 void audioEvent(unsigned int index);
 void audioPlay(unsigned int index, uint8_t id=0);
-void audioStart();

 #if defined(AUDIO) && defined(BUZZER)
  #define AUDIO_BUZZER(a, b)  do { a; b; } while(0)
@@ -76,7 +76,7 @@ void menuRadioDiagFS(event_t event)
    lcdDrawText(FS_1ST_COLUMN + 7, y, getFSPhysicalState(i) ? STR_CHAR_DOWN : STR_CHAR_UP);
    lcdDrawText(FS_2ND_COLUMN + 5, y, getFSLogicalState(i) ? STR_CHAR_DOWN : STR_CHAR_UP);
 #if defined(FUNCTION_SWITCHES_RGB_LEDS)
-    lcdDrawText(FS_3RD_COLUMN, y, STR_FS_COLOR_LIST[getRGBColorIndex(rgbGetLedColor(i))], 0);
+    lcdDrawText(FS_3RD_COLUMN, y, STR_FS_COLOR_LIST[getRGBColorIndex(fsGetLedRGB(i))], 0);
 #else
    lcdDrawText(FS_3RD_COLUMN, y, STR_OFFON[fsLedState(i)]);
 #endif
@@ -102,11 +102,7 @@ void waitSplash()
 {
  // Handle color splash screen
  if (splashStartTime) {
-#if defined(SIMU)
-    // Simulator - inputsMoved() returns true immediately without this!
-    sleep_ms(30);
-#endif  // defined(SIMU)
-
+    inactivityCheckInputs();
    splashStartTime += SPLASH_TIMEOUT;
    while (splashStartTime >= get_tmr10ms()) {
      LvglWrapper::instance()->run();
@@ -30,7 +30,7 @@ set(BOOTLOADER_SRC ${BOOTLOADER_SRC}
  ${CMAKE_CURRENT_SOURCE_DIR}/hal/key_driver.cpp
 )

-if (NOT NATIVE_BUILD)
+if ((NOT NATIVE_BUILD) OR SIMU_DISKIO)
  set(SRC ${SRC}
    hal/storage.cpp
    hal/fatfs_diskio.cpp
@@ -24,7 +24,10 @@

 #include "debug.h"

-#if defined(STORAGE_USE_SDIO)
+#if defined(SIMU_DISKIO)
+  extern const diskio_driver_t simu_diskio_driver;
+  #define _STORAGE_DRIVER simu_diskio_driver
+#elif defined(STORAGE_USE_SDIO)
  #include "diskio_sdio.h"
  #define _STORAGE_DRIVER sdio_diskio_driver
 #elif defined(STORAGE_USE_SDCARD_SPI)
@@ -52,6 +52,11 @@ void inactivityTimerReset(ActivitySource src)
 #define INAC_STICKS_SHIFT   7
 #define INAC_SWITCHES_SHIFT 8

+static inline int8_t inactivity_diff(uint8_t sum)
+{
+  return abs((int8_t)(sum - inactivity.sum));
+}
+
 bool inactivityCheckInputs()
 {
  uint8_t sum = 0;
@@ -78,7 +83,7 @@ bool inactivityCheckInputs()
    sum += get_spacemouse_value(i) >> INAC_STICKS_SHIFT;
 #endif

-  if (abs((int8_t)(sum - inactivity.sum)) > 1) {
+  if (inactivity_diff(sum) > 1) {
    inactivity.sum = sum;
    return true;
  } else {
@@ -109,7 +109,7 @@ FRESULT sdReadDir(DIR * dir, FILINFO * fno, bool & firstTime)
  return res;
 }

-#if !defined(BOOT) && !defined(SIMU)
+#if !defined(BOOT) && (!defined(SIMU) || defined(SIMU_DISKIO))

 // Replace FatFS implementation of f_puts and f_printf

@@ -4,6 +4,8 @@

 #include <algorithm>

+using namespace std::chrono_literals;
+
 static timer_queue* _instance = nullptr;
 static std::mutex _instance_mut;

@@ -565,7 +565,7 @@ void sdDone()

 uint32_t sdMounted()
 {
-#if defined(SIMU)
+#if defined(SIMU) && !defined(SIMU_DISKIO)
  return true;
 #else
  return _g_FATFS_init && (g_FATFS_Obj.fs_type != 0);
@@ -1,727 +0,0 @@
-/*
- * Copyright (C) EdgeTX
- *
- * Based on code named
- *   opentx - https://github.com/opentx/opentx
- *   th9x - http://code.google.com/p/th9x
- *   er9x - http://code.google.com/p/er9x
- *   gruvin9x - http://code.google.com/p/gruvin9x
- *
- * License GPLv2: http://www.gnu.org/licenses/gpl-2.0.html
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * 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.
- */
-
-#if defined(SIMU_AUDIO)
-  #include <SDL.h>
-  #undef main
-#endif
-
-#include "fx.h"
-#include "FXExpression.h"
-#include "FXPNGImage.h"
-#include <unistd.h>
-#include "fxkeys.h"
-#include "edgetx.h"
-#include <time.h>
-#include <ctype.h>
-
-#include "targets/simu/simulcd.h"
-#include "hal/adc_driver.h"
-#include "hal/rotary_encoder.h"
-
-#include "os/time.h"
-
-#if LCD_W > 212
-  #define LCD_ZOOM 1
-#else
-  #define LCD_ZOOM 2
-#endif
-
-#define W2 LCD_W*LCD_ZOOM
-#define H2 LCD_H*LCD_ZOOM
-
-#if defined(HARDWARE_TOUCH)
-  #define TAP_TIME 25
-
-  tmr10ms_t now = 0;
-  tmr10ms_t downTime = 0;
-  tmr10ms_t tapTime = 0;
-  short tapCount = 0;
-#endif
-
-class OpenTxSim: public FXMainWindow
-{
-  FXDECLARE(OpenTxSim)
-
-  public:
-    OpenTxSim(){};
-    OpenTxSim(FXApp* a);
-    ~OpenTxSim();
-    void updateKeysAndSwitches(bool start=false);
-    long onKeypress(FXObject*, FXSelector, void*);
-    long onMouseDown(FXObject*,FXSelector,void*);
-    long onMouseUp(FXObject*,FXSelector,void*);
-    long onMouseMove(FXObject*,FXSelector,void*);
-    long onTimeout(FXObject*, FXSelector, void*);
-    void createBitmap(int index, uint16_t *data, int x, int y, int w, int h);
-    void makeSnapshot(const FXDrawable* drawable);
-    void doEvents();
-    void refreshDisplay();
-    void setPixel(int x, int y, FXColor color);
-    void fsLedRGB(uint8_t idx, uint32_t color);
-
-  private:
-    FXImage * bmp;
-    FXImageFrame * bmf;
-
-  public:
-    FXSlider * sliders[MAX_STICKS];
-    FXKnob * knobs[MAX_POTS];
-#if defined(FUNCTION_SWITCHES)
-    FXButton * fctButtons[NUM_FUNCTIONS_SWITCHES] = {0};
-#endif
-};
-
-// Message Map
-FXDEFMAP(OpenTxSim) OpenTxSimMap[] = {
-  // Message_Type   _______ID____Message_Handler_______
-  FXMAPFUNC(SEL_TIMEOUT,   2,    OpenTxSim::onTimeout),
-  FXMAPFUNC(SEL_KEYPRESS,  0,    OpenTxSim::onKeypress),
-  FXMAPFUNC(SEL_LEFTBUTTONPRESS, 0, OpenTxSim::onMouseDown),
-  FXMAPFUNC(SEL_LEFTBUTTONRELEASE, 0, OpenTxSim::onMouseUp),
-  FXMAPFUNC(SEL_MOTION,    0,    OpenTxSim::onMouseMove),
-};
-
-FXIMPLEMENT(OpenTxSim, FXMainWindow, OpenTxSimMap, ARRAYNUMBER(OpenTxSimMap))
-
-OpenTxSim::OpenTxSim(FXApp* a):
-  FXMainWindow(a, "EdgeTX Simu", nullptr, nullptr, DECOR_ALL, 20, 90, 0, 0)
-{
-  bmp = new FXPPMImage(getApp(), nullptr, IMAGE_OWNED|IMAGE_KEEP|IMAGE_SHMI|IMAGE_SHMP, W2, H2);
-
-#if defined(SIMU_AUDIO)
-  #if defined(_WIN32) || defined(_WIN64)
-  putenv("SDL_AUDIODRIVER=directsound");
-  #endif
-  SDL_Init(SDL_INIT_AUDIO);
-#endif
-
-  FXHorizontalFrame * hf11 = new FXHorizontalFrame(this, LAYOUT_CENTER_X);
-#if defined(FUNCTION_SWITCHES)
-  FXHorizontalFrame * hf12 = new FXHorizontalFrame(this, LAYOUT_CENTER_X);
-#endif
-  FXHorizontalFrame * hf1 = new FXHorizontalFrame(this, LAYOUT_FILL_X);
-
-  //rh lv rv lh
-  for (int i=0; i<4; i++) {
-    switch (i) {
-#define L LAYOUT_FIX_WIDTH|LAYOUT_FIX_HEIGHT|LAYOUT_FIX_X|LAYOUT_FIX_Y
-      case 0:
-        sliders[i]=new FXSlider(hf1, nullptr, 0, L|SLIDER_HORIZONTAL, 10, 110, 100, 20);
-        break;
-      case 1:
-        sliders[i]=new FXSlider(hf1, nullptr, 0, L|SLIDER_VERTICAL, 110, 10, 20, 100);
-        break;
-      case 2:
-        sliders[i]=new FXSlider(hf1, nullptr, 0, L|SLIDER_VERTICAL, 130, 10, 20, 100);
-        break;
-      case 3:
-        sliders[i]=new FXSlider(hf1, nullptr, 0, L|SLIDER_HORIZONTAL, 150, 110, 100, 20);
-        break;
-      default:;
-    }
-    sliders[i]->setTickDelta(14);
-    sliders[i]->setRange(0, 4095);
-    sliders[i]->setValue(2047);
-  }
-
-  auto max_pots = adcGetMaxInputs(ADC_INPUT_FLEX);
-  memset(knobs, 0, sizeof(knobs));
-  
-  for (int i = 0; i < max_pots; i++) {
-    knobs[i]= new FXKnob(hf11, nullptr, 0, KNOB_TICKS|LAYOUT_LEFT);
-    knobs[i]->setRange(0, 4095);
-    knobs[i]->setValue(2047);
-
-#if defined(PCBHORUS) && !defined(FUNCTION_SWITCHES)
-    if (i == 1) {  // 6-pos switch
-      knobs[i]->setIncrement(4095 / 5);
-      knobs[i]->setTickDelta(4095 / 5);
-      knobs[i]->setValue(0);
-      continue;
-    }
-#endif
-  }
-
-#if defined(FUNCTION_SWITCHES)
-  for(int i = 0; i < NUM_FUNCTIONS_SWITCHES; ++i)
-  {
-    fctButtons[i] = new FXButton(hf12, "     ", nullptr, nullptr, 123, LAYOUT_LEFT|BUTTON_NORMAL, 0, 0, 50, 0, 15, 15);
-    fctButtons[i]->setBorderColor(FXColor(0));
-  }
-#endif
-
-  bmf = new FXImageFrame(this, bmp);
-  bmf->enable();
-  bmf->setTarget(this);
-
-  updateKeysAndSwitches(true);
-
-  getApp()->addTimeout(this, 2, 100);
-}
-
-OpenTxSim::~OpenTxSim()
-{
-  TRACE("OpenTxSim::~OpenTxSim()");
-
-  simuStop();
-
-  delete bmp;
-  delete sliders[0];
-  delete sliders[1];
-  delete sliders[2];
-  delete sliders[3];
-
-  for (int i = 0; i < MAX_POTS; i++) {
-    delete knobs[i];
-  }
-
-  delete bmf;
-
-#if defined(SIMU_AUDIO)
-  SDL_Quit();
-#endif
-}
-
-void OpenTxSim::createBitmap(int index, uint16_t *data, int x, int y, int w, int h)
-{
-  FXPNGImage snapshot(getApp(), nullptr, IMAGE_OWNED, w, h);
-
-  for (int i=0; i<w; i++) {
-    for (int j=0; j<h; j++) {
-      pixel_t z = data[(y+j) * LCD_W + (x+i)];
-      FXColor color = FXRGB(255*((z&0xF00)>>8)/0x0f, 255*((z&0x0F0)>>4)/0x0f, 255*(z&0x00F)/0x0f);
-      snapshot.setPixel(i, j, color);
-    }
-  }
-
-  FXFileStream stream;
-  char buf[32];
-  sprintf(buf, "%02d.png", index);
-  if (stream.open(buf, FXStreamSave)) {
-    snapshot.savePixels(stream);
-    stream.close();
-    TRACE("Bitmap %d (w=%d, h=%d) created", index, w, h);
-  }
-  else {
-    TRACE("Bitmap %d (w=%d, h=%d) error", index, w, h);
-  }
-}
-
-void OpenTxSim::makeSnapshot(const FXDrawable* drawable)
-{
-  // Construct and create an FXImage object
-  FXPNGImage snapshot(getApp(), nullptr, 0, drawable->getWidth(), drawable->getHeight());
-  snapshot.create();
-
-  // Create a window device context and lock it onto the image
-  FXDCWindow dc(&snapshot);
-
-  // Draw from the widget to this
-  dc.drawArea(drawable, 0, 0, drawable->getWidth(), drawable->getHeight(), 0, 0);
-
-  // Release lock
-  dc.end();
-
-  // Grab pixels from server side back to client side
-  snapshot.restore();
-
-  // Save recovered pixels to a file
-  FXFileStream stream;
-  char buf[100];
-
-  do {
-    stream.close();
-    sprintf(buf, "snapshot_%02d.png", ++g_snapshot_idx);
-  } while (stream.open(buf, FXStreamLoad));
-
-  if (stream.open(buf, FXStreamSave)) {
-    snapshot.savePixels(stream);
-    stream.close();
-    printf("Snapshot written: %s\n", buf);
-  }
-  else {
-    printf("Cannot create snapshot %s\n", buf);
-  }
-}
-
-void OpenTxSim::doEvents()
-{
-  getApp()->runOneEvent(false);
-}
-
-long OpenTxSim::onKeypress(FXObject *, FXSelector, void * v)
-{
-  auto * evt = (FXEvent *)v;
-
-  // TRACE("keypress %x", evt->code);
-
-  if (evt->code == 's') {
-    makeSnapshot(bmf);
-  }
-
-  return 0;
-}
-
-long OpenTxSim::onMouseDown(FXObject *, FXSelector, void * v)
-{
-  FXEvent * evt = (FXEvent *)v;
-  UNUSED(evt);
-
-  TRACE_WINDOWS("[Mouse Press] %d %d", evt->win_x, evt->win_y);
-
-#if defined(HARDWARE_TOUCH)
-  now = get_tmr10ms();
-  simTouchState.tapCount = 0;
-
-  simTouchState.event = TE_DOWN;
-  simTouchState.startX = simTouchState.x = evt->win_x;
-  simTouchState.startY = simTouchState.y = evt->win_y;
-  downTime = now;
-  simTouchOccured = true;
-#endif
-
-  return 0;
-}
-
-long OpenTxSim::onMouseUp(FXObject*,FXSelector,void*v)
-{
-  FXEvent * evt = (FXEvent *)v;
-  UNUSED(evt);
-
-  TRACE_WINDOWS("[Mouse Release] %d %d", evt->win_x, evt->win_y);
-
-#if defined(HARDWARE_TOUCH)
-  now = get_tmr10ms();
-
-  if (simTouchState.event == TE_DOWN) {
-    simTouchState.event = TE_UP;
-    simTouchState.x = simTouchState.startX;
-    simTouchState.y = simTouchState.startY;
-    if (now - downTime <= TAP_TIME) {
-      if (now - tapTime > TAP_TIME)
-        tapCount = 1;
-      else
-        tapCount++;
-      simTouchState.tapCount = tapCount;
-      tapTime = now;
-    }
-  }
-  else {
-    simTouchState.event = TE_SLIDE_END;
-  }
-  simTouchOccured = true;
-#endif
-
-  return 0;
-}
-
-long OpenTxSim::onMouseMove(FXObject*,FXSelector,void*v)
-{
-  FXEvent * evt = (FXEvent *)v;
-  UNUSED(evt);
-
-  if (evt->state & LEFTBUTTONMASK) {
-    TRACE_WINDOWS("[Mouse Move] %d %d", evt->win_x, evt->win_y);
-
-#if defined(HARDWARE_TOUCH)
-    simTouchState.deltaX += evt->win_x - simTouchState.x;
-    simTouchState.deltaY += evt->win_y - simTouchState.y;
-    if (simTouchState.event == TE_SLIDE || abs(simTouchState.deltaX) >= SLIDE_RANGE || abs(simTouchState.deltaY) >= SLIDE_RANGE) {
-      simTouchState.event = TE_SLIDE;
-      simTouchState.x = evt->win_x;
-      simTouchState.y = evt->win_y;
-    }
-    simTouchOccured = true;
-#endif
-  }
-
-  return 0;
-}
-
-void OpenTxSim::updateKeysAndSwitches(bool start)
-{
-  static int keys[] = {
-#if defined(PCBFLYSKY)
-    // no keys
-#elif defined(PCBHORUS)
-    KEY_Page_Up,   KEY_PAGEUP,
-    KEY_Page_Down, KEY_PAGEDN,
-    KEY_Return,    KEY_ENTER,
-    KEY_BackSpace, KEY_EXIT,
-    KEY_Up,        KEY_UP,
-    KEY_Down,      KEY_DOWN,
-    KEY_Right,     KEY_RIGHT,
-    KEY_Left,      KEY_LEFT,
-#elif defined(PCBXLITE) || defined(RADIO_FAMILY_JUMPER_T12)
-  #if defined(KEYS_GPIO_REG_SHIFT)
-    KEY_Shift_L,   KEY_SHIFT,
-  #endif
-    KEY_Return,    KEY_ENTER,
-    KEY_BackSpace, KEY_EXIT,
-    KEY_Right,     KEY_RIGHT,
-    KEY_Left,      KEY_LEFT,
-    KEY_Up,        KEY_UP,
-    KEY_Down,      KEY_DOWN,
-#elif defined(NAVIGATION_X7_TX12)
-    KEY_Page_Up,   KEY_PAGEUP,
-    KEY_Page_Down, KEY_PAGEDN,
-    KEY_Return,    KEY_ENTER,
-    KEY_BackSpace, KEY_EXIT,
-    KEY_Up,        KEY_MODEL,
-    KEY_Down,      KEY_EXIT,
-    KEY_Right,     KEY_TELE,
-    KEY_Left,      KEY_SYS,
-#elif defined(RADIO_T8) || defined(RADIO_COMMANDO8)
-    KEY_Page_Up,   KEY_PAGEUP,
-    KEY_Page_Down, KEY_PAGEDN,
-    KEY_Return,    KEY_ENTER,
-    KEY_Right,     KEY_MODEL,
-    KEY_BackSpace, KEY_EXIT,
-    KEY_Left,      KEY_SYS,
-    KEY_Up,        KEY_PLUS,
-    KEY_Down,      KEY_MINUS,
-#elif defined(PCBTARANIS)
-    KEY_Page_Up,   KEY_MENU,
-    KEY_Page_Down, KEY_PAGEDN,
-    KEY_Return,    KEY_ENTER,
-    KEY_BackSpace, KEY_EXIT,
-    KEY_Up,        KEY_PLUS,
-    KEY_Down,      KEY_MINUS,
-#else
-    KEY_Return,    KEY_MENU,
-    KEY_BackSpace, KEY_EXIT,
-    KEY_Right,     KEY_RIGHT,
-    KEY_Left,      KEY_LEFT,
-    KEY_Up,        KEY_UP,
-    KEY_Down,      KEY_DOWN,
-#endif
-  };
-
-  for (unsigned int i=0; i<DIM(keys); i+=2) {
-    simuSetKey(keys[i+1], start ? false : getApp()->getKeyState(keys[i]));
-  }
-
-#ifdef __APPLE__
-  static FXuint trimKeys[] = { KEY_1, KEY_2, KEY_3, KEY_4, KEY_5, KEY_6, KEY_7, KEY_8, KEY_9, KEY_0 };
-#else
-  static FXuint trimKeys[] = { KEY_F1, KEY_F2, KEY_F3, KEY_F4, KEY_F5, KEY_F6, KEY_F7, KEY_F8, KEY_F9, KEY_F10, KEY_F11, KEY_F12 };
-#endif
-
-  for (unsigned i = 0; i < sizeof(trimKeys) / sizeof(FXuint); i++) {
-    simuSetTrim(i, getApp()->getKeyState(trimKeys[i]));
-  }
-
-#define SWITCH_KEY(key, swtch, states) \
-  static bool state##key = 0; \
-  static int8_t state_##swtch = -1; \
-  static int8_t inc_##swtch = 4-states; \
-  if (getApp()->getKeyState(KEY_##key)) { \
-    if (!state##key) { \
-      state_##swtch = (state_##swtch+inc_##swtch); \
-      if (state_##swtch == -1+((states-1)*inc_##swtch)) inc_##swtch = -4+states; \
-      else if (state_##swtch == -1) inc_##swtch = 4-states; \
-      state##key = true; \
-    } \
-  } \
-  else { \
-    state##key = false; \
-  } \
-  simuSetSwitch(swtch, state_##swtch) \
-
-  SWITCH_KEY(A, 0, 3);
-  SWITCH_KEY(B, 1, 3);
-  SWITCH_KEY(C, 2, 3);
-  SWITCH_KEY(D, 3, 3);
-
-  #if defined(RADIO_TPRO) || defined(RADIO_TPROV2) || defined(RADIO_TPROS) || defined(RADIO_BUMBLEBEE)
-    SWITCH_KEY(1, 4, 2);
-    SWITCH_KEY(2, 5, 2);
-    SWITCH_KEY(3, 6, 2);
-    SWITCH_KEY(4, 7, 2);
-    SWITCH_KEY(5, 8, 2);
-    SWITCH_KEY(6, 9, 2);
-  #elif defined(HARDWARE_SWITCH_G) && defined(HARDWARE_SWITCH_H)
-    SWITCH_KEY(E, 4, 3);
-    SWITCH_KEY(F, 5, 2);
-    SWITCH_KEY(G, 6, 3);
-    SWITCH_KEY(H, 7, 2);
-  #elif defined(HARDWARE_SWITCH_F) && defined(HARDWARE_SWITCH_H)
-    SWITCH_KEY(F, 4, 2);
-    SWITCH_KEY(H, 5, 2);
-  #endif
-
-  #if defined(PCBX9E)
-    SWITCH_KEY(I, 8, 3);
-    SWITCH_KEY(J, 9, 3);
-    SWITCH_KEY(K, 10, 3);
-    SWITCH_KEY(L, 11, 3);
-    SWITCH_KEY(M, 12, 3);
-    SWITCH_KEY(N, 13, 3);
-    SWITCH_KEY(O, 14, 3);
-    SWITCH_KEY(P, 15, 3);
-    SWITCH_KEY(Q, 16, 3);
-    SWITCH_KEY(R, 17, 3);
-  #endif
-
-#if defined(FUNCTION_SWITCHES)
-    for(int i = 0; i < NUM_FUNCTIONS_SWITCHES; ++i)
-    {
-      int8_t newState = -1;
-      if(fctButtons[i]->getState()==STATE_DOWN)
-      {
-        newState = 1;
-      }
-
-      simuSetSwitch(switchGetMaxSwitches() + i, newState);
-    }
-#endif
-}
-
-extern volatile rotenc_t rotencValue;
-extern volatile uint32_t rotencDt;
-
-long OpenTxSim::onTimeout(FXObject*, FXSelector, void*)
-{
-  if (hasFocus()) {
-
-    updateKeysAndSwitches();
-
-#if defined(ROTARY_ENCODER_NAVIGATION)
-    static bool rotencAction = false;
-    if (getApp()->getKeyState(KEY_X) || getApp()->getKeyState(KEY_plus)) {
-      if (!rotencAction) rotencValue += ROTARY_ENCODER_GRANULARITY;
-      rotencAction = true;
-    }
-    else if (getApp()->getKeyState(KEY_W) || getApp()->getKeyState(KEY_minus)) {
-      if (!rotencAction) rotencValue -= ROTARY_ENCODER_GRANULARITY;
-      rotencAction = true;
-    }
-    else {
-      rotencAction = false;
-    }
-
-    static uint32_t last_tick = 0;
-    if (rotencAction) {
-      uint32_t now = time_get_ms();
-      uint32_t dt = now - last_tick;
-      rotencDt += dt;
-      last_tick = now;
-    }
-#endif
-  }
-
-#if defined(SIMU_BOOTLOADER)
-  void interrupt10ms();
-  interrupt10ms();
-#endif
-
-  refreshDisplay();
-  getApp()->addTimeout(this, 2, 10);
-  return 0;
-}
-
-#if LCD_W >= 212
-  #define BL_COLOR FXRGB(47, 123, 227)
-#else
-  #define BL_COLOR FXRGB(150, 200, 152)
-#endif
-
-void OpenTxSim::setPixel(int x, int y, FXColor color)
-{
-#if LCD_ZOOM > 1
-  for (int i=0; i<LCD_ZOOM; ++i) {
-    for (int j=0; j<LCD_ZOOM; ++j) {
-      bmp->setPixel(LCD_ZOOM*x+i, LCD_ZOOM*y+j, color);
-    }
-  }
-#else
-  bmp->setPixel(x, y, color);
-#endif
-}
-
-// from lcd driver
-void lcdFlushed();
-
-void OpenTxSim::refreshDisplay()
-{
-  static bool lightEnabled = (bool)isBacklightEnabled();
-
-  if ((bool(isBacklightEnabled()) != lightEnabled) || simuLcdRefresh) {
-
-    if (bool(isBacklightEnabled()) != lightEnabled) {
-      lightEnabled = (bool)isBacklightEnabled();
-      TRACE("backlight %s", lightEnabled ? "ON" : "OFF");
-    }
-
-#if !defined(COLORLCD)
-    FXColor offColor = isBacklightEnabled() ? BL_COLOR : FXRGB(200, 200, 200);
-#if LCD_DEPTH == 1
-    FXColor onColor = FXRGB(0, 0, 0);
-#endif
-#endif
-    for (int x = 0; x < LCD_W; x++) {
-      for (int y = 0; y < LCD_H; y++) {
-#if defined(COLORLCD)
-        pixel_t z = simuLcdBuf[y * LCD_W + x];
-        FXColor color =
-          FXRGB(((z & 0xF800) >> 8) + ((z & 0xE000) >> 13),
-                ((z & 0x07E0) >> 3) + ((z & 0x0600) >> 9),
-                (((z & 0x001F) << 3) & 0x00F8) + ((z & 0x001C) >> 2));
-        setPixel(x, y, color);
-#else
-#if LCD_DEPTH == 4
-        pixel_t *p = &simuLcdBuf[y / 2 * LCD_W + x];
-        uint8_t z = (y & 1) ? (*p >> 4) : (*p & 0x0F);
-        if (z) {
-          FXColor color;
-          if (isBacklightEnabled())
-            color = FXRGB(47 - (z * 47) / 15, 123 - (z * 123) / 15,
-                          227 - (z * 227) / 15);
-          else
-            color = FXRGB(200 - (z * 200) / 15, 200 - (z * 200) / 15,
-                          200 - (z * 200) / 15);
-          setPixel(x, y, color);
-        }
-#else  // LCD_DEPTH == 1
-        if (simuLcdBuf[x + (y / 8) * LCD_W] & (1 << (y % 8))) {
-          setPixel(x, y, onColor);
-        }
-#endif
-        else {
-          setPixel(x, y, offColor);
-        }
-#endif  // !defined(COLORLCD)
-      }
-    }
-#if defined(COLORLCD)
-    if (!lightEnabled) { bmp->fade(0, 50); }
-#endif
-
-    bmp->render();
-    bmf->setImage(bmp);
-
-    simuLcdRefresh = false;
-    lcdFlushed();
-  }
-}
-
-void OpenTxSim::fsLedRGB(uint8_t idx, uint32_t color)
-{
-#if defined(FUNCTION_SWITCHES)
-  uint32_t col = (color&0x00FF0000)>>16 | (color&0x0000FF00) | (color&0x000000FF)<<16;
-  fctButtons[idx]->setBaseColor(col);
-  fctButtons[idx]->setBackColor(col);
-#endif
-}
-
-OpenTxSim * opentxSim;
-
-void doFxEvents()
-{
-  //puts("doFxEvents");
-  opentxSim->getApp()->runOneEvent(false);
-  opentxSim->refreshDisplay();
-}
-
-int main(int argc, char ** argv)
-{
-  // Each FOX GUI program needs one, and only one, application object.
-  // The application objects coordinates some common stuff shared between
-  // all the widgets; for example, it dispatches events, keeps track of
-  // all the windows, and so on.
-  // We pass the "name" of the application, and its "vendor", the name
-  // and vendor are used to search the registry database (which stores
-  // persistent information e.g. fonts and colors).
-  FXApp application("OpenTX Simu", "OpenTX");
-
-  // Here we initialize the application.  We pass the command line arguments
-  // because FOX may sometimes need to filter out some of the arguments.
-  // This opens up the display as well, and reads the registry database
-  // so that persistent settings are now available.
-  application.init(argc, argv);
-
-  simuInit();
-
-  // This creates the main window. We pass in the title to be displayed
-  // above the window, and possibly some icons for when its iconified.
-  // The decorations determine stuff like the borders, close buttons,
-  // drag handles, and so on the Window Manager is supposed to give this
-  // window.
-  //FXMainWindow *main=new FXMainWindow(&application, "Hello", nullptr, nullptr, DECOR_ALL);
-  opentxSim = new OpenTxSim(&application);
-  application.create();
-
-  // Pretty self-explanatory:- this shows the window, and places it in the
-  // middle of the screen.
-#ifndef __APPLE__
-  opentxSim->show(PLACEMENT_SCREEN);
-#else
-  opentxSim->show(); // Otherwise the main window gets centred across my two monitors, split down the middle.
-#endif
-
-  printf("Model size = %d\n", (int)sizeof(g_model));
-
-#if !defined(SIMU_BOOTLOADER)
-  startAudio();
-#endif
-
-  simuStart(true/*false*/, argc >= 3 ? argv[2] : 0, argc >= 4 ? argv[3] : 0);
-
-  return application.run();
-}
-
-uint16_t simu_get_analog(uint8_t idx)
-{
-  auto max_sticks = adcGetMaxInputs(ADC_INPUT_MAIN);
-  if (idx < max_sticks)
-    return opentxSim->sliders[idx]->getValue();
-
-  idx -= max_sticks;
-
-  auto max_pots = adcGetMaxInputs(ADC_INPUT_FLEX);
-  if (idx < max_pots)
-    return opentxSim->knobs[idx]->getValue();
-
-  // probably RTC_BAT
-  return 0;
-}
-
-void createBitmap(int index, uint16_t *data, int x, int y, int w, int h)
-{
-  opentxSim->createBitmap(index, data, x, y, w, h);
-}
-
-
-void fsLedRGB(uint8_t idx, uint32_t color)
-{
-  opentxSim->fsLedRGB(idx, color);
-}
-
-void fsLedOn(uint8_t idx)
-{
-  opentxSim->fsLedRGB(idx, 0x00ffffff);
-}
-
-void fsLedOff(uint8_t idx)
-{
-  opentxSim->fsLedRGB(idx, 0);
-}
@@ -21,8 +21,10 @@

 #pragma once

-#include <cinttypes>
+#include <stdint.h>
+#include <stdlib.h>

+#include "edgetx_types.h"
 #include "edgetx_constants.h"

 enum LogicalSwitchFamilies {
@@ -1,15 +1,25 @@

-option(SIMU_TARGET "Configure libsimulator/simu targets (can be turned off for compiling Companion only)" ON)
+option(SIMU_TARGET "Configure libsimulator/simu targets" ON)
 if(NOT SIMU_TARGET)
  message(STATUS "libsimulator/simu targets disabled")
  return()
 endif()

+target_compile_options(radiolib_native PUBLIC -DSIMU)
+
+if(SDL2_FOUND)
+  option(SIMU_AUDIO "Enable simulator audio." ON)
+  if(SIMU_AUDIO)
+    target_compile_options(radiolib_native PUBLIC -DSIMU_AUDIO)
+  endif()
+endif()
+
 set(SIMU_DRIVERS
  simpgmspace.cpp
  simufatfs.cpp
  simudisk.cpp
  simulcd.cpp
+  simuaudio.cpp
  switch_driver.cpp
  adc_driver.cpp
  module_drivers.cpp
@@ -156,60 +166,44 @@ if(WIN32)
  endif()
 endif(WIN32)

-if(MSVC)
-  set(CMAKE_CXX_FLAGS "/EHsc")
-  if(NOT CLANG)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /LD /MP")
-  endif()
-else()
-  if(MINGW)
-    # struct packing breaks on MinGW w/out -mno-ms-bitfields: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52991 & http://stackoverflow.com/questions/24015852/struct-packing-and-alignment-with-mingw
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mno-ms-bitfields")
-  endif()
-  set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -O0")
-  set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -O0")
-  if(ASAN)
-    set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -fsanitize=address")
-    set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -fsanitize=address")
-  endif()
+if(MINGW)
+  # struct packing breaks on MinGW w/out -mno-ms-bitfields: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52991 & http://stackoverflow.com/questions/24015852/struct-packing-and-alignment-with-mingw
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mno-ms-bitfields")
+endif()
+
+set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -O0")
+set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -O0")
+
+if(ASAN)
+  set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -fsanitize=address")
+  set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -fsanitize=address")
 endif()

 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${WARNING_FLAGS}")
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${WARNING_FLAGS}")

+add_executable(simu
+  EXCLUDE_FROM_ALL
+  ${SIMU_SRC}
+  display.cpp
+  widgets.cpp
+  knobs.cpp
+  sdl_simu.cpp
+)

-if(FOX_FOUND)
-  add_executable(simu WIN32
-    EXCLUDE_FROM_ALL
-    ${SIMU_SRC}
-    ${RADIO_SRC_DIR}/simu.cpp)
+include(FetchImgui)
+target_compile_options(simu PUBLIC -DSIMU)

-  target_include_directories(simu PUBLIC ${FOX_INCLUDE_DIR} )
-  target_link_libraries(simu ${FOX_LIBRARY} pthread ${SDL2_LIBRARIES})
-  target_compile_options(simu PRIVATE ${SIMU_SRC_OPTIONS})
-endif()
+add_png_target(image_assets "assets/images/*.png")
+add_dependencies(simu image_assets)

-if(APPLE)
-  # OS X compiler no longer automatically includes /Library/Frameworks in search path
-  set(CMAKE_SHARED_LINKER_FLAGS -F/Library/Frameworks)
+set(STB_DIR ${RADIO_SRC_DIR}/thirdparty/stb)
+target_include_directories(simu PUBLIC ${STB_DIR})
+target_link_libraries(simu PUBLIC imgui)

-  set(SIMULATOR_BUNDLES)
-  foreach(library ${OPENTX_LIBRARIES})
-    set(SIMULATOR_BUNDLE "${library}-bundle")
-    add_custom_target(${SIMULATOR_BUNDLE}
-      COMMAND install_name_tool -change /opt/local/Library/Frameworks/QtCore.framework/Versions/4/QtCore @executable_path/../Frameworks/QtCore.framework/Versions/4/QtCore lib${library}.dylib
-      COMMAND install_name_tool -change /opt/local/Library/Frameworks/QtNetwork.framework/Versions/4/QtNetwork @executable_path/../Frameworks/QtNetwork.framework/Versions/4/QtNetwork lib${library}.dylib
-      COMMAND install_name_tool -change /opt/local/Library/Frameworks/QtXml.framework/Versions/4/QtXml @executable_path/../Frameworks/QtXml.framework/Versions/4/QtXml lib${library}.dylib
-      COMMAND install_name_tool -change /opt/local/Library/Frameworks/QtGui.framework/Versions/4/QtGui @executable_path/../Frameworks/QtGui.framework/Versions/4/QtGui lib${library}.dylib
-      COMMAND install_name_tool -change @rpath/SDL.framework/Versions/A/SDL @executable_path/../Frameworks/SDL.framework/Versions/A/SDL lib${library}.dylib
-      WORKING_DIRECTORY ${PROJECT_BINARY_DIR}
-      COMMAND pwd
-      COMMAND cp lib${library}.dylib companion.app/Contents/Resources/
-      DEPENDS ${library}
-      )
-    list(APPEND SIMULATOR_BUNDLES ${SIMULATOR_BUNDLE})
-  endforeach()
-  add_custom_target(opentx-simulators-bundle DEPENDS ${SIMULATOR_BUNDLES})
-endif(APPLE)
+  target_link_libraries(simu PUBLIC
+    pthread
+    ${SDL2_LIBRARIES}
+  )

 PrintTargetReport("simu/libsimulator")
@@ -19,11 +19,35 @@
 * GNU General Public License for more details.
 */

+#include "board.h"
+
 bool boardBacklightOn = false;
 bool isBacklightEnabled() { return boardBacklightOn; }
-void backlightFullOn() { boardBacklightOn = true; }

 void backlightInit() {}
-void backlightEnable(unsigned char) {}
-void backlightEnable(unsigned char, unsigned char) {}
-void backlightDisable() {}
+
+#if !defined(COLORLCD)
+
+void backlightFullOn() { boardBacklightOn = true; }
+
+void backlightEnable(unsigned char)
+{
+  boardBacklightOn = true;
+}
+
+void backlightEnable(unsigned char, unsigned char)
+{
+  boardBacklightOn = true;  
+}
+
+void backlightDisable()
+{
+  boardBacklightOn = false;
+}
+
+#else
+
+void backlightFullOn() { backlightEnable(BACKLIGHT_LEVEL_MAX); }
+void backlightEnable(uint8_t) {}
+
+#endif
@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) EdgeTX
+ *
+ * Based on code named
+ *   opentx - https://github.com/opentx/opentx
+ *   th9x - http://code.google.com/p/th9x
+ *   er9x - http://code.google.com/p/er9x
+ *   gruvin9x - http://code.google.com/p/gruvin9x
+ *
+ * License GPLv2: http://www.gnu.org/licenses/gpl-2.0.html
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#include "display.h"
+#include "simu.h"
+
+static void _set_pixel(uint8_t* pixel, const SDL_Color& color)
+{
+  pixel[0] = color.a;
+  pixel[1] = color.b;
+  pixel[2] = color.g;
+  pixel[3] = color.r;
+}
+
+static void _blit_simu_screen_color(void* screen_buffer, Uint32 format, int w, int h, int pitch)
+{
+  pixel_t* src_buffer = simuLcdBuf;
+  uint8_t* line_buffer = (uint8_t*)screen_buffer;
+
+  for (int y = 0; y < h; y++) {
+    for (int x = 0; x < w; x++) {
+      pixel_t z = *src_buffer++;
+      // Alpha
+      line_buffer[0] = SDL_ALPHA_OPAQUE;
+      // Blue
+      line_buffer[1] = (((z & 0x001F) << 3) & 0x00F8) + ((z & 0x001C) >> 2);
+      // Green
+      line_buffer[2] = ((z & 0x07E0) >> 3) + ((z & 0x0600) >> 9);
+      // Red
+      line_buffer[3] = ((z & 0xF800) >> 8) + ((z & 0xE000) >> 13);
+      line_buffer += SDL_BYTESPERPIXEL(format);
+    }
+  }
+}
+
+static void _blit_simu_screen_1bit(void* screen_buffer, Uint32 format, int w, int h, int pitch)
+{
+  const SDL_Color on_color = {.r = 0, .g = 0, .b = 0};
+
+  uint8_t* line_buffer = (uint8_t*)screen_buffer;
+
+  for (int y = 0; y < h; y++) {
+    for (int x = 0; x < w; x++) {
+      SDL_Color c = on_color;
+      if (simuLcdBuf[x + (y / 8) * w] & (1 << (y % 8))) {
+        c.a = SDL_ALPHA_OPAQUE;
+      } else {
+        c.a = SDL_ALPHA_TRANSPARENT;
+      }
+      _set_pixel(line_buffer, c);
+      line_buffer += SDL_BYTESPERPIXEL(format);
+    }
+  }
+}
+
+// static inline uint8_t _4bit_blend(uint16_t px, uint16_t bg)
+// {
+//   uint16_t c = bg * (16 - px);
+//   return c / 16;
+// }
+
+static void _blit_simu_screen_4bit(void* screen_buffer, Uint32 format, int w, int h, int pitch)
+{
+  const SDL_Color on_color = {.r = 0, .g = 0, .b = 0};
+
+  uint8_t* line_buffer = (uint8_t*)screen_buffer;
+
+  for (int y = 0; y < h; y++) {
+    for (int x = 0; x < w; x++) {
+
+      pixel_t p = simuLcdBuf[y / 2 * LCD_W + x];
+      uint8_t z = (y & 1) ? (p >> 4) : (p & 0x0F);
+
+      SDL_Color c = on_color;
+      c.a = (uint16_t)z * SDL_ALPHA_OPAQUE / 16;
+
+      _set_pixel(line_buffer, c);
+      line_buffer += SDL_BYTESPERPIXEL(format);
+    }
+  }
+}
+
+void refreshDisplay(SDL_Texture* screen)
+{
+  if (simuLcdRefresh) {
+
+    // fetch texture format
+    Uint32 format = 0;
+    int width = 0, height = 0;
+
+    if (SDL_QueryTexture(screen, &format, nullptr, &width, &height) != 0) {
+      SDL_Log("SDL_QueryTexture: %s", SDL_GetError());
+      return;
+    }
+    
+    // raw pixel buffer
+    void* screen_buffer = nullptr;
+
+    // length of one row in bytes
+    int pitch = 0;
+
+    if (SDL_LockTexture(screen, nullptr, &screen_buffer, &pitch) != 0) {
+      SDL_Log("SDL_LockTexture: %s", SDL_GetError());
+      return;
+    }
+
+    if (LCD_DEPTH == 1) {
+      _blit_simu_screen_1bit(screen_buffer, format, width, height, pitch);
+    } else if (LCD_DEPTH == 4) {
+      _blit_simu_screen_4bit(screen_buffer, format, width, height, pitch);
+    } else if (LCD_DEPTH == 16) {
+      _blit_simu_screen_color(screen_buffer, format, width, height, pitch);
+    }
+
+    SDL_UnlockTexture(screen);
+    simuLcdRefresh = false;
+    lcdFlushed();
+  }
+}
+
+
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) EdgeTX
+ *
+ * Based on code named
+ *   opentx - https://github.com/opentx/opentx
+ *   th9x - http://code.google.com/p/th9x
+ *   er9x - http://code.google.com/p/er9x
+ *   gruvin9x - http://code.google.com/p/gruvin9x
+ *
+ * License GPLv2: http://www.gnu.org/licenses/gpl-2.0.html
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#include <SDL.h>
+
+// display methods
+void refreshDisplay(SDL_Texture* screen);
@@ -19,6 +19,7 @@
 * GNU General Public License for more details.
 */

-void gyroInit() {}
-void gyroRead() {}
-void gyroRead(unsigned char*) {}
+#include "gyro.h"
+
+int gyroInit() { return -1; }
+int gyroRead(uint8_t*) { return -1; }
@@ -0,0 +1,259 @@
+//
+// Code from:
+//   https://github.com/altschuler/imgui-knobs
+//
+// Copyright (c) 2022 Simon Altschuler
+// 
+// MIT License
+//
+
+#include "knobs.h"
+
+#include <cmath>
+#include <cstdlib>
+#include <imgui.h>
+#include <imgui_internal.h>
+
+#define IMGUIKNOBS_PI 3.14159265358979323846f
+
+namespace ImGuiKnobs
+{
+namespace detail
+{
+
+template <typename DataType>
+struct knob {
+  float radius;
+  bool value_changed;
+  ImVec2 center;
+  bool is_active;
+  bool is_hovered;
+  float angle_min;
+  float angle_max;
+  float t;
+  float angle;
+  float angle_cos;
+  float angle_sin;
+
+  knob(const char *_label, ImGuiDataType data_type, DataType *p_value,
+       DataType v_min, DataType v_max, float _radius,
+       const char *format, ImGuiKnobFlags flags)
+  {
+    radius = _radius;
+    t = ((float)*p_value - v_min) / (v_max - v_min);
+    auto screen_pos = ImGui::GetCursorScreenPos();
+
+    ImGui::InvisibleButton(_label, {radius * 2.0f, radius * 2.0f});
+
+    angle_min = IMGUIKNOBS_PI * 0.75f;
+    angle_max = IMGUIKNOBS_PI * 2.25f;
+    center = {screen_pos.x + radius, screen_pos.y + radius};
+    is_active = ImGui::IsItemActive();
+    is_hovered = ImGui::IsItemHovered();
+    angle = angle_min + (angle_max - angle_min) * t;
+    angle_cos = cosf(angle);
+    angle_sin = sinf(angle);
+
+    if (is_active) {
+      ImVec2 mp = ImGui::GetIO().MousePos;
+      float angle_mid = (angle_max + angle_min) / 2.0;
+      float alpha = atan2f(mp.x - center.x, center.y - mp.y) + angle_mid;
+      alpha = ImClamp(alpha, angle_min, angle_max);
+      float ratio = (alpha - angle_min) / (angle_max - angle_min);
+      switch(data_type){
+      case ImGuiDataType_Float:
+        *p_value = ImGui::ScaleValueFromRatioT<ImS32, ImS32, float>(
+            data_type, ratio, v_min, v_max, false, 0.0f, 0.0f);
+        break;
+      case ImGuiDataType_S32:
+        *p_value = ImGui::ScaleValueFromRatioT<float, float, float>(
+            data_type, ratio, v_min, v_max, false, 0.0f, 0.0f);
+        break;
+      default: break;
+      }
+    }
+  }
+
+  void draw_dot(float size, float radius, float angle, color_set color,
+                bool filled, int segments)
+  {
+    auto dot_size = size * this->radius;
+    auto dot_radius = radius * this->radius;
+
+    ImGui::GetWindowDrawList()->AddCircleFilled(
+        {center[0] + cosf(angle) * dot_radius,
+         center[1] + sinf(angle) * dot_radius},
+        dot_size,
+        is_active ? color.active : (is_hovered ? color.hovered : color.base),
+        segments);
+  }
+
+  void draw_tick(float start, float end, float width, float angle,
+                 color_set color)
+  {
+    auto tick_start = start * radius;
+    auto tick_end = end * radius;
+    auto angle_cos = cosf(angle);
+    auto angle_sin = sinf(angle);
+
+    ImGui::GetWindowDrawList()->AddLine(
+        {center[0] + angle_cos * tick_end, center[1] + angle_sin * tick_end},
+        {center[0] + angle_cos * tick_start,
+         center[1] + angle_sin * tick_start},
+        is_active ? color.active : (is_hovered ? color.hovered : color.base),
+        width * radius);
+  }
+
+  void draw_circle(float size, color_set color, bool filled, int segments)
+  {
+    auto circle_radius = size * radius;
+
+    ImGui::GetWindowDrawList()->AddCircleFilled(
+        center, circle_radius,
+        is_active ? color.active : (is_hovered ? color.hovered : color.base));
+  }
+};
+
+template <typename DataType>
+knob<DataType> knob_with_title(const char *label, ImGuiDataType data_type,
+                               DataType *p_value, DataType v_min, DataType v_max,
+                               const char *format, float size,
+                               ImGuiKnobFlags flags)
+{
+  ImGui::PushID(label);
+  auto width = size == 0 ? ImGui::GetTextLineHeight() * 4.0f
+                         : size * ImGui::GetIO().FontGlobalScale;
+  ImGui::PushItemWidth(width);
+
+  ImGui::BeginGroup();
+
+  // There's an issue with `SameLine` and Groups, see
+  // https://github.com/ocornut/imgui/issues/4190. This is probably not the best
+  // solution, but seems to work for now
+  ImGui::GetCurrentWindow()->DC.CurrLineTextBaseOffset = 0;
+
+  // Draw title
+  if (!(flags & ImGuiKnobFlags_NoTitle)) {
+    auto title_size = ImGui::CalcTextSize(label, NULL, false, width);
+
+    // Center title
+    ImGui::SetCursorPosX(ImGui::GetCursorPosX() +
+                         (width - title_size[0]) * 0.5f);
+
+    ImGui::Text("%s", label);
+  }
+
+  // Draw knob
+  knob<DataType> k(label, data_type, p_value, v_min, v_max, width * 0.5f,
+                   format, flags);
+
+  // Draw tooltip
+  if (ImGui::IsItemHovered(ImGuiHoveredFlags_AllowWhenDisabled) ||
+      ImGui::IsItemActive()) {
+
+    if (flags & ImGuiKnobFlags_ValueTooltip && ImGui::IsItemActive()) {
+      ImGui::SetTooltip(format, *p_value);
+    } else if (flags & ImGuiKnobFlags_TitleTooltip) {
+      ImGui::SetTooltip("%s", label);
+    }
+  }
+
+  ImGui::EndGroup();
+  ImGui::PopItemWidth();
+  ImGui::PopID();
+
+  return k;
+}
+
+color_set GetPrimaryColorSet()
+{
+  auto *colors = ImGui::GetStyle().Colors;
+
+  return {colors[ImGuiCol_ButtonActive], colors[ImGuiCol_ButtonHovered],
+          colors[ImGuiCol_ButtonHovered]};
+}
+
+color_set GetSecondaryColorSet()
+{
+  auto *colors = ImGui::GetStyle().Colors;
+  auto active = ImVec4(colors[ImGuiCol_ButtonActive].x * 0.5f,
+                       colors[ImGuiCol_ButtonActive].y * 0.5f,
+                       colors[ImGuiCol_ButtonActive].z * 0.5f,
+                       colors[ImGuiCol_ButtonActive].w);
+
+  auto hovered = ImVec4(colors[ImGuiCol_ButtonHovered].x * 0.5f,
+                        colors[ImGuiCol_ButtonHovered].y * 0.5f,
+                        colors[ImGuiCol_ButtonHovered].z * 0.5f,
+                        colors[ImGuiCol_ButtonHovered].w);
+
+  return {active, hovered, hovered};
+}
+
+color_set GetTrackColorSet()
+{
+  auto *colors = ImGui::GetStyle().Colors;
+
+  return {colors[ImGuiCol_FrameBg], colors[ImGuiCol_FrameBg],
+          colors[ImGuiCol_FrameBg]};
+}
+}  // namespace detail
+
+template <typename DataType>
+bool BaseKnob(const char *label, ImGuiDataType data_type, DataType *p_value,
+              DataType v_min, DataType v_max, const char *format,
+              ImGuiKnobVariant variant, float size, ImGuiKnobFlags flags,
+              int steps = 10)
+{
+  auto knob = detail::knob_with_title(label, data_type, p_value, v_min, v_max,
+                                      format, size, flags);
+
+  switch (variant) {
+    case ImGuiKnobVariant_Tick: {
+      knob.draw_circle(0.85f, detail::GetSecondaryColorSet(), true, 32);
+      knob.draw_tick(0.5f, 0.85f, 0.1f, knob.angle,
+                     detail::GetPrimaryColorSet());
+      break;
+    }
+    case ImGuiKnobVariant_Dot: {
+      knob.draw_circle(0.85f, detail::GetSecondaryColorSet(), true, 32);
+      knob.draw_dot(0.12f, 0.6f, knob.angle, detail::GetPrimaryColorSet(), true,
+                    12);
+      break;
+    }
+
+    case ImGuiKnobVariant_Stepped: {
+      for (auto n = 0.f; n < steps; n++) {
+        auto a = n / (steps - 1);
+        auto angle = knob.angle_min + (knob.angle_max - knob.angle_min) * a;
+        knob.draw_tick(0.85f, 1.0f, 0.04f, angle, detail::GetPrimaryColorSet());
+      }
+
+      knob.draw_circle(0.75f, detail::GetSecondaryColorSet(), true, 32);
+      knob.draw_dot(0.12f, 0.4f, knob.angle, detail::GetPrimaryColorSet(), true,
+                    12);
+      break;
+    }
+  }
+
+  return knob.value_changed;
+}
+
+bool Knob(const char *label, float *p_value, float v_min, float v_max,
+          float speed, const char *format, ImGuiKnobVariant variant, float size,
+          ImGuiKnobFlags flags, int steps)
+{
+  const char *_format = format == NULL ? "%.3f" : format;
+  return BaseKnob(label, ImGuiDataType_Float, p_value, v_min, v_max,
+                  _format, variant, size, flags, steps);
+}
+
+bool KnobInt(const char *label, int *p_value, int v_min, int v_max, float speed,
+             const char *format, ImGuiKnobVariant variant, float size,
+             ImGuiKnobFlags flags, int steps)
+{
+  const char *_format = format == NULL ? "%i" : format;
+  return BaseKnob(label, ImGuiDataType_S32, p_value, v_min, v_max,
+                  _format, variant, size, flags, steps);
+}
+
+}  // namespace ImGuiKnobs
@@ -0,0 +1,57 @@
+//
+// Code from:
+//   https://github.com/altschuler/imgui-knobs
+//
+// Copyright (c) 2022 Simon Altschuler
+// 
+// MIT License
+//
+
+#include <imgui.h>
+
+typedef int ImGuiKnobFlags;
+
+enum ImGuiKnobFlags_ {
+    ImGuiKnobFlags_NoTitle = 1 << 0,
+    ImGuiKnobFlags_ValueTooltip = 1 << 1,
+    ImGuiKnobFlags_TitleTooltip = 1 << 2,
+};
+
+typedef int ImGuiKnobVariant;
+
+enum ImGuiKnobVariant_ {
+    ImGuiKnobVariant_Tick = 1,
+    ImGuiKnobVariant_Dot,
+    ImGuiKnobVariant_Stepped,
+};
+
+namespace ImGuiKnobs {
+
+    struct color_set {
+        ImColor base;
+        ImColor hovered;
+        ImColor active;
+
+        color_set(ImColor base, ImColor hovered, ImColor active) :
+            base(base), hovered(hovered), active(active)
+        {
+        }
+
+        color_set(ImColor color) {
+            base = color;
+            hovered = color;
+            active = color;
+        }
+    };
+
+    bool Knob(const char* label, float* p_value, float v_min, float v_max,
+              float speed = 0, const char* format = NULL,
+              ImGuiKnobVariant variant = ImGuiKnobVariant_Tick, float size = 0,
+              ImGuiKnobFlags flags = 0, int steps = 10);
+
+    bool KnobInt(const char* label, int* p_value, int v_min, int v_max,
+                 float speed = 0, const char* format = NULL,
+                 ImGuiKnobVariant variant = ImGuiKnobVariant_Tick,
+                 float size = 0, ImGuiKnobFlags flags = 0, int steps = 10);
+
+}  // namespace ImGuiKnobs
@@ -23,13 +23,15 @@
 #include "hal/rgbleds.h"
 #include "definitions.h"

+#include "board.h"
+
 bool usbChargerLed() { return true; }
 void ledRed() {}
 void ledGreen() {}
 void ledBlue() {}
 void ledOff() {}
-bool fsLedState(uint8_t) { return false;}
-void rgbSetLedColor(unsigned char, unsigned char, unsigned char, unsigned char) {}
+
+void rgbSetLedColor(uint8_t, uint8_t, uint8_t, uint8_t) {}
 void rgbLedColorApply() {}

 uint8_t getRGBColorIndex(uint32_t color)
@@ -41,24 +43,39 @@ uint8_t getRGBColorIndex(uint32_t color)
  return 0; // Custom value set with Companion
 }

-// RGB
-#define WS2812_BYTES_PER_LED 3
+#if NUM_FUNCTIONS_SWITCHES > 0
+static uint32_t _fs_switch_colors[NUM_FUNCTIONS_SWITCHES] = {0};
+static uint32_t _fs_switch_color_mask = 0;
+static uint32_t _fs_switch_mask = 0;

-// Maximum number of supported LEDs
-#if !defined(WS2812_MAX_LEDS)
-#  define WS2812_MAX_LEDS 48
-#endif
-
-// Pixel values
-static uint8_t _led_colors[WS2812_BYTES_PER_LED * WS2812_MAX_LEDS];
-
-uint32_t rgbGetLedColor(uint8_t led)
+void fsLedRGB(uint8_t index, uint32_t col)
 {
-  uint8_t* pixel = &_led_colors[led * WS2812_BYTES_PER_LED];
-  return  (pixel[1] << 16) +  (pixel[0] << 8) + pixel[2];
+  _fs_switch_color_mask |= (1 << index);
+  _fs_switch_colors[index] = col;
 }

 uint32_t fsGetLedRGB(uint8_t index)
 {
-  return rgbGetLedColor(index);
+  return _fs_switch_colors[index];
 }
+
+bool fsLedIsColorSet(uint8_t index)
+{
+  return _fs_switch_color_mask & (1 << index);
+}
+
+bool fsLedState(uint8_t index)
+{
+  return _fs_switch_mask & (1 << index);
+}
+
+void fsLedOn(uint8_t index)
+{
+  _fs_switch_mask |= (1 << index);
+}
+
+void fsLedOff(uint8_t index)
+{
+  _fs_switch_mask &= ~(1 << index);
+}
+#endif
@@ -22,6 +22,7 @@
 #include "opentxsimulator.h"
 #include "edgetx.h"
 #include "simulcd.h"
+#include "simuaudio.h"
 #include "switches.h"
 #include "serial.h"
 #include "myeeprom.h"
@@ -89,18 +90,6 @@ void firmwareTraceCb(const char * text)
  }
 }

-void fsLedRGB(uint8_t idx, uint32_t color)
-{
-}
-
-void fsLedOn(uint8_t idx)
-{
-}
-
-void fsLedOff(uint8_t idx)
-{
-}
-
 // Serial port handling needs to know about OpenTxSimulator, so we we
 // need to update what's in simpgmspace.cpp when we have a simulator
 // to point at.
@@ -283,7 +272,7 @@ void OpenTxSimulator::start(const char * filename, bool tests)

  QMutexLocker lckr(&m_mtxSimuMain);
  QMutexLocker slckr(&m_mtxSettings);
-  startAudio(volumeGain);
+  simuAudioInit();
  simuStart(tests, simuSdDirectory.toLatin1().constData(),
            simuSettingsDirectory.toLatin1().constData());

@@ -301,6 +290,7 @@ void OpenTxSimulator::stop()

  QMutexLocker lckr(&m_mtxSimuMain);
  simuStop();
+  simuAudioDeInit();

  emit stopped();
 }
@@ -0,0 +1,908 @@
+/*
+ * Copyright (C) EdgeTX
+ *
+ * Based on code named
+ *   opentx - https://github.com/opentx/opentx
+ *   th9x - http://code.google.com/p/th9x
+ *   er9x - http://code.google.com/p/er9x
+ *   gruvin9x - http://code.google.com/p/gruvin9x
+ *
+ * License GPLv2: http://www.gnu.org/licenses/gpl-2.0.html
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#include <SDL.h>
+#include <SDL_keycode.h>
+
+#include <imgui.h>
+#include <imgui_impl_sdl2.h>
+#include <imgui_impl_sdlrenderer2.h>
+
+#include <libgen.h>
+#include <getopt.h>
+
+#include <algorithm>
+#include <iostream>
+#include <fstream>
+#include <regex>
+#include <string>
+
+#include "hal/adc_driver.h"
+#include "hal/rotary_encoder.h"
+#include "hal/switch_driver.h"
+
+#if !SDL_VERSION_ATLEAST(2,0,19)
+#error This backend requires SDL 2.0.19+ because of SDL_RenderGeometryRaw() function
+#endif
+
+#if defined(__clang__)
+#pragma clang diagnostic ignored "-Wunused-function"
+#elif defined(__GNUC__)
+#pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
+#define STB_IMAGE_IMPLEMENTATION
+#define STB_IMAGE_STATIC
+#include "stb_image.h"
+
+#if defined(STBI_NO_STDIO)
+  #error "STBI_NO_STDIO is defined"
+#endif
+
+#include "simu.h"
+#include "widgets.h"
+#include "knobs.h"
+#include "display.h"
+
+#include "simuaudio.h"
+#include "simpgmspace.h"
+
+#include "hal/key_driver.h"
+#include "switches.h"
+
+#include "audio.h"
+#include "debug.h"
+#include "edgetx.h"
+
+#define TIMER_INTERVAL 10 // 10ms
+
+int window_width = 800;
+int window_height = 600;
+
+std::string storage_path;
+std::string settings_path;
+
+static SDL_Window* window;
+static SDL_Renderer* renderer;
+static SDL_Texture* screen_frame_buffer;
+
+static GimbalState stick_left = {{0.5f, 0.5f}, false};
+static GimbalState stick_right = {{0.5f, 0.5f}, false};
+
+static const unsigned char _icon_png[] = {
+#include "icon.lbm"
+};
+
+#if defined(ROTARY_ENCODER_NAVIGATION)
+extern volatile rotenc_t rotencValue;
+#endif
+
+int pots[MAX_POTS] = {0};
+
+static bool handleKeyEvents(SDL_Event& event)
+{
+  if (event.type == SDL_KEYDOWN || event.type == SDL_KEYUP) {
+    const auto& key_event = event.key;
+
+    bool key_handled = false;
+    uint8_t key = 0;
+    
+    switch(key_event.keysym.sym) {
+
+    case SDLK_ESCAPE:
+      key = KEY_EXIT;
+      key_handled = true;
+      break;
+      
+    case SDLK_RETURN:
+      key = KEY_ENTER;
+      key_handled = true;
+      break;
+
+    case SDLK_LEFT:
+      if (keysGetSupported() & (1 << KEY_LEFT)) {
+        key = KEY_LEFT;
+        key_handled = true;
+      }
+      break;
+      
+    case SDLK_RIGHT:
+      if (keysGetSupported() & (1 << KEY_RIGHT)) {
+        key = KEY_RIGHT;
+        key_handled = true;
+      }
+      break;
+
+    case SDLK_UP:
+#if defined(ROTARY_ENCODER_NAVIGATION)
+      if (event.type == SDL_KEYDOWN) {
+        rotencValue -= ROTARY_ENCODER_GRANULARITY;
+      }
+#else
+      if (keysGetSupported() & (1 << KEY_UP)) {
+        key = KEY_UP;
+        key_handled = true;
+      }
+#endif
+      break;
+      
+    case SDLK_DOWN:
+#if defined(ROTARY_ENCODER_NAVIGATION)
+      if (event.type == SDL_KEYDOWN) {
+        rotencValue += ROTARY_ENCODER_GRANULARITY;
+      }
+#else
+      if (keysGetSupported() & (1 << KEY_DOWN)) {
+        key = KEY_DOWN;
+        key_handled = true;
+      }
+#endif
+      break;
+
+    case SDLK_PLUS:
+      if (keysGetSupported() & (1 << KEY_PLUS)) {
+        key = KEY_PLUS;
+        key_handled = true;
+      }
+      break;
+
+    case SDLK_MINUS:
+      if (keysGetSupported() & (1 << KEY_MINUS)) {
+        key = KEY_MINUS;
+        key_handled = true;
+      }
+      break;
+
+    case SDLK_PAGEUP:
+      if (keysGetSupported() & (1 << KEY_PAGEUP)) {
+        key = KEY_PAGEUP;
+        key_handled = true;
+      }
+      break;
+
+    case SDLK_PAGEDOWN:
+      if (keysGetSupported() & (1 << KEY_PAGEDN)) {
+        key = KEY_PAGEDN;
+        key_handled = true;
+      }
+      break;
+
+    case SDLK_m:
+      if (keysGetSupported() & (1 << KEY_MENU)) {
+        key = KEY_MENU;
+        key_handled = true;
+      } else if (keysGetSupported() & (1 << KEY_MODEL)) {
+        key = KEY_MODEL;
+        key_handled = true;     
+      }
+      break;
+
+    case SDLK_s:
+      if (keysGetSupported() & (1 << KEY_SYS)) {
+        key = KEY_SYS;
+        key_handled = true;
+      }
+      break;
+
+    case SDLK_t:
+      if (keysGetSupported() & (1 << KEY_TELE)) {
+        key = KEY_TELE;
+        key_handled = true;
+      }
+      break;
+
+    case SDLK_l:
+      ImGui::StyleColorsLight();
+      break;
+
+    case SDLK_d:
+      ImGui::StyleColorsDark();
+      break;
+
+    case SDLK_r:
+      if (event.type == SDL_KEYUP) {
+        simuStop();
+        simuStart();
+      }
+      break;
+
+    default:
+      key_handled = false;
+      break;
+    }
+
+    if (key_handled) {
+      simuSetKey(key, key_event.type == SDL_KEYDOWN ? true : false);
+    }
+
+    return key_handled;
+  }
+
+  return false;
+}
+
+static void redraw();
+
+static bool handleEvents()
+{
+  SDL_Event event;
+  while (SDL_PollEvent(&event)) {
+
+    if(handleKeyEvents(event))
+      continue;
+      
+    ImGui_ImplSDL2_ProcessEvent(&event);
+
+    if (event.type == SDL_QUIT)
+      return false;
+
+    if (event.type == SDL_WINDOWEVENT &&
+        event.window.event == SDL_WINDOWEVENT_CLOSE &&
+        event.window.windowID == SDL_GetWindowID(window))
+      return false;
+  }
+
+  redraw();
+  return true;
+}
+
+static SDL_Surface* LoadImage(const unsigned char* pixels, size_t len)
+{
+  // Read data
+  int32_t w, h, bpp;
+
+  void* data = stbi_load_from_memory(pixels, len, &w, &h, &bpp, 0);
+  if (!data) return NULL;
+
+  Uint32 format = (bpp == 3) ? SDL_PIXELFORMAT_RGB24 : SDL_PIXELFORMAT_RGBA32;
+
+  SDL_Surface* surface = SDL_CreateRGBSurfaceWithFormat(0, w, h, bpp * 8, format);
+  if (surface) {
+    SDL_LockSurface(surface);
+    memcpy(surface->pixels, data, w * h * bpp);
+    SDL_UnlockSurface(surface);
+  }
+
+  stbi_image_free(data);
+  return surface;
+}
+
+static SDL_Texture* LoadTexture(SDL_Renderer* renderer, const unsigned char* pixels, size_t len)
+{
+  SDL_Surface* surface = LoadImage(pixels, len);
+  if (!surface) return NULL;
+
+  SDL_Texture* texture = SDL_CreateTextureFromSurface(renderer, surface);
+  SDL_FreeSurface(surface);
+
+  return texture;
+}
+
+
+static float switches_width()
+{
+  const int max_sw_line = MAX_SWITCHES / 2;
+  const int sw_line = std::min((int)switchGetMaxSwitches(), max_sw_line);
+  return sw_line * 18 + (sw_line - 1) * 4;
+}
+
+static void draw_switches()
+{
+  const float spacing = 4;
+  const ImVec2 sw_size(18, 50);
+
+  ImGui::PushID("switches");
+  {
+    static int switches[MAX_SWITCHES] = {0};
+
+    ImGui::BeginGroup();
+    ImGui::PushStyleVar(ImGuiStyleVar_ItemSpacing, ImVec2(spacing, spacing));
+    ImGui::PushStyleVar(ImGuiStyleVar_FrameRounding, 4.0f);
+    ImGui::PushStyleVar(ImGuiStyleVar_GrabRounding, 4.0f);
+
+    int sw_idx = 0;
+    for (int i = 0; i < switchGetMaxSwitches(); i++) {
+      if (sw_idx) ImGui::SameLine();
+      if (++sw_idx >= MAX_SWITCHES / 2) sw_idx = 0;
+
+      if (!SWITCH_EXISTS(i)) {
+        switches[i] = 0;
+        ImGui::Dummy(sw_size);
+      } else {
+        ImGui::PushID(i);
+        ImGui::VSliderInt("##sw", sw_size,
+                          &switches[i], IS_CONFIG_3POS(i) ? 2 : 1,
+                          0, "", ImGuiSliderFlags_NoInput);
+        if (ImGui::IsItemActive() || ImGui::IsItemHovered()) {
+          ImGui::SetTooltip("%s", switchGetCanonicalName(i));
+        }
+        ImGui::PopID();
+      }
+      
+      if (IS_CONFIG_3POS(i)) {
+        simuSetSwitch(i, switches[i] == 0 ? -1 : switches[i] == 1 ? 0 : 1);
+      } else {
+        simuSetSwitch(i, switches[i] == 0 ? -1 : 1);
+      }
+    }
+
+    ImGui::PopStyleVar(3);
+    ImGui::EndGroup();
+  }
+  ImGui::PopID();
+}
+
+#if defined(FUNCTION_SWITCHES)
+extern bool fsLedIsColorSet(uint8_t index);
+
+static ImVec4 rgb2rgba(uint32_t col)
+{
+  float r = (float)((col >> 16) & 0xff) / 255.0f;
+  float g = (float)((col >>  8) & 0xff) / 255.0f;
+  float b = (float)((col >>  0) & 0xff) / 255.0f;
+  return {r, g, b, 1.0f};
+}
+
+static inline ImVec4 blend(const ImVec4& a, const ImVec4& b)
+{
+  float w0 = a.w + b.w;
+  return ImVec4((a.x * a.w + b.x * b.w) / w0, (a.y * a.w + b.y * b.w) / w0,
+                (a.z * a.w + b.z * b.w) / w0, 1.0f);
+}
+
+static void push_custom_switch_styles(int index)
+{
+  bool sw_on = getFSLogicalState(index);
+  bool rgb_set = fsLedIsColorSet(index);
+  ImVec4 rgb = rgb2rgba(fsGetLedRGB(index));
+
+  ImVec4 btn, border;
+  if (sw_on) {
+    btn = rgb_set ? rgb : ImGui::GetStyleColorVec4(ImGuiCol_SliderGrab);
+    border = ImGui::GetStyleColorVec4(ImGuiCol_SliderGrab);
+  } else {
+    btn = rgb_set ? rgb : ImGui::GetStyleColorVec4(ImGuiCol_FrameBg);
+    border = ImGui::GetStyleColorVec4(ImGuiCol_FrameBg);
+  }
+
+  // color intensity
+  float btn_int = (btn.x + btn.y + btn.z) / 3.0f;
+  float inv_int = 1.0f - btn_int;
+  ImVec4 mask(inv_int, inv_int, inv_int, 0.3f);
+
+  ImGui::PushStyleColor(ImGuiCol_Button, btn);
+  ImGui::PushStyleColor(ImGuiCol_ButtonHovered, blend(btn, mask));
+  ImGui::PushStyleColor(ImGuiCol_Border, border);
+
+  ImGui::PushStyleVar(ImGuiStyleVar_FrameBorderSize, 3.0f);
+}
+
+static void pop_custom_switch_styles()
+{
+  ImGui::PopStyleColor(3);
+  ImGui::PopStyleVar();
+}
+
+static void draw_custom_switches()
+{
+  const float spacing = 4;
+  const ImVec2 sw_size(18, 18);
+
+  ImGui::PushID("custom switches");
+  {
+    ImGui::BeginGroup();
+    ImGui::PushStyleVar(ImGuiStyleVar_ItemSpacing, ImVec2(spacing, spacing));
+    ImGui::PushStyleVar(ImGuiStyleVar_FrameRounding, 4.0f);
+    ImGui::PushStyleVar(ImGuiStyleVar_GrabRounding, 4.0f);
+
+    int sw_idx = switchGetMaxSwitches();
+    for (int i = 0; i < switchGetMaxFctSwitches(); i++, sw_idx++) {
+      if (i) ImGui::SameLine();
+      ImGui::PushID(i);
+
+      push_custom_switch_styles(i);
+      ImGui::Button("##csw", sw_size);
+      pop_custom_switch_styles();
+
+      bool active = ImGui::IsItemActive();
+      if (active || ImGui::IsItemHovered()) {
+        const char* name = switchGetCanonicalName(sw_idx);
+        const char* on_off = getFSLogicalState(i) ? "on" : "off";
+        ImGui::SetTooltip("%s (%s)", name, on_off);
+      }
+      simuSetSwitch(sw_idx, active ? 1 : -1);
+
+      ImGui::PopID();
+    }
+
+    ImGui::PopStyleVar(3);
+    ImGui::EndGroup();
+  }
+  ImGui::PopID();
+}
+#endif
+
+static float gimbals_width()
+{
+  return 244.0f;
+}
+
+static void draw_gimbals()
+{
+  stick_left.lock_y = (g_eeGeneral.stickMode == 1);
+  stick_right.lock_y = (g_eeGeneral.stickMode == 0);
+
+  GimbalPair("#gimbals", stick_left, stick_right);
+}
+
+static float pots_width()
+{
+  const float spacing = 2;
+  float pot_width = ImGui::GetTextLineHeight() * 4.0f;
+  int pots = std::min((int)adcGetMaxInputs(ADC_INPUT_FLEX), 5);
+  return pots * pot_width + (pots - 1) * spacing +
+         2 * ImGui::GetStyle().CellPadding.x;
+}
+
+static void draw_pots()
+{
+  const float spacing = 2;
+  ImGui::PushStyleVar(ImGuiStyleVar_ItemSpacing, ImVec2(spacing, spacing));
+  ImGui::PushID("pots");
+  {
+    ImGui::BeginGroup();
+    int pot_idx = 0;
+    for (int i = 0; i < adcGetMaxInputs(ADC_INPUT_FLEX); i++) {
+      if (pot_idx > 0) ImGui::SameLine();
+      if (++pot_idx >= 5) pot_idx = 0;
+
+      if (!IS_POT_AVAILABLE(i)) {
+        pots[i] = 0;
+        auto sz = ImGui::GetTextLineHeight() * 4.0f;
+        ImGui::Dummy({sz, sz});
+      } else {
+        ImGui::PushID(i);
+        auto flags = ImGuiKnobFlags_NoTitle | ImGuiKnobFlags_ValueTooltip |
+                     ImGuiKnobFlags_TitleTooltip;
+        auto label = adcGetInputLabel(ADC_INPUT_FLEX, i);
+        switch(getPotType(i)) {
+        case FLEX_POT:
+        case FLEX_POT_CENTER:
+        case FLEX_SLIDER:
+          ImGuiKnobs::KnobInt(label, &pots[i], -100, 100, 1, "%d",
+                              ImGuiKnobVariant_Tick, 0, flags);
+          break;
+
+        case FLEX_MULTIPOS:
+          ImGuiKnobs::KnobInt(label, &pots[i], 0, 5, 0.2f, "%d",
+                              ImGuiKnobVariant_Stepped, 0, flags, 6);
+          break;
+        }
+        ImGui::PopID();
+      }
+    }
+    ImGui::EndGroup();
+  }
+  ImGui::PopID();
+  ImGui::PopStyleVar();
+}
+
+void draw_controls()
+{
+  ImGui::BeginTable("controls", 3, ImGuiTableFlags_SizingFixedFit);
+  ImGui::TableSetupColumn("", ImGuiTableColumnFlags_WidthFixed, switches_width());
+  ImGui::TableSetupColumn("", ImGuiTableColumnFlags_WidthFixed, gimbals_width());
+  ImGui::TableSetupColumn("", ImGuiTableColumnFlags_WidthFixed, pots_width());
+
+  ImGui::TableNextColumn();
+  draw_switches();
+#if defined(FUNCTION_SWITCHES)
+  draw_custom_switches();
+#endif
+  
+  ImGui::TableNextColumn();
+  draw_gimbals();
+
+  ImGui::TableNextColumn();
+  draw_pots();
+
+  ImGui::EndTable();
+}
+
+ImU32 get_bg_color()
+{
+  if (LCD_DEPTH < 16) {
+    if (isBacklightEnabled()) {
+      return IM_COL32(47, 123, 227, 255);
+    } else {
+      return IM_COL32(200, 200, 200, 255);
+    }
+  } else {
+    return IM_COL32_BLACK_TRANS;
+  }
+}
+
+static ImVec2 calc_screen_size()
+{
+  float width, height;
+
+  height = ImGui::GetContentRegionAvail().y;
+  width = height * float(LCD_W) / float(LCD_H);
+
+  if (width > ImGui::GetContentRegionAvail().x) {
+    width = ImGui::GetContentRegionAvail().x;
+    height = width * float(LCD_H) / float(LCD_W);
+  }
+
+  return {width, height};
+}
+
+static void draw_screen()
+{
+  const ScreenDesc desc = {
+    .width = LCD_W,
+    .height = LCD_H,
+    .is_dot_matrix = LCD_DEPTH == 1 || LCD_DEPTH == 4,
+  };
+
+  auto size = calc_screen_size();
+  SimuScreen(desc, (ImTextureID)screen_frame_buffer, size, get_bg_color(),
+             (LCD_DEPTH == 16 && !isBacklightEnabled()) ?
+             IM_COL32(0,0,0,127) : IM_COL32_BLACK_TRANS);
+
+#if defined(HARDWARE_TOUCH)
+  ScreenMouseEvent touch_event;
+  if (SimuScreenMouseEvent(desc, touch_event)) {
+    if (touch_event.type == ScreenMouseEventType::MouseDown) {
+      touchPanelDown(touch_event.pos_x, touch_event.pos_y);
+    } else {
+      touchPanelUp();
+    }
+  }
+#endif
+}
+
+static int get_used_window_height()
+{
+  return (int)ImGui::GetCursorScreenPos().y;
+}
+
+static int calc_min_width()
+{
+  return switches_width() + gimbals_width() + pots_width() +
+         6 * ImGui::GetStyle().CellPadding.x;
+}
+
+static void redraw()
+{
+  refreshDisplay(screen_frame_buffer);
+    
+  // Start the Dear ImGui frame
+  ImGui_ImplSDLRenderer2_NewFrame();
+  ImGui_ImplSDL2_NewFrame();
+  ImGui::NewFrame();
+
+  static ImGuiWindowFlags flags =
+    ImGuiWindowFlags_NoDecoration | ImGuiWindowFlags_NoMove |
+    ImGuiWindowFlags_NoSavedSettings | ImGuiWindowFlags_NoCollapse |
+    ImGuiWindowFlags_NoTitleBar;
+
+  // Use full work area (without menu-bars, task-bars etc.)
+  const ImGuiViewport* viewport = ImGui::GetMainViewport();
+  ImGui::SetNextWindowPos(viewport->WorkPos);
+  ImGui::SetNextWindowSize(viewport->WorkSize);
+
+  bool show_win = true;
+
+  if (ImGui::Begin("Main window", &show_win, flags)) {
+    draw_controls();
+    draw_screen();
+  }
+  ImGui::End();
+
+  // Rendering
+  ImGui::Render();
+
+  ImGuiIO& io = ImGui::GetIO();
+  SDL_RenderSetScale(renderer, io.DisplayFramebufferScale.x,
+                     io.DisplayFramebufferScale.y);
+
+  auto bg_col = ImGui::GetColorU32(ImGuiCol_WindowBg);
+  SDL_SetRenderDrawColor(renderer,
+                         (bg_col >> IM_COL32_R_SHIFT) & 0xFF,
+                         (bg_col >> IM_COL32_G_SHIFT) & 0xFF,
+                         (bg_col >> IM_COL32_B_SHIFT) & 0xFF,
+                         (bg_col >> IM_COL32_A_SHIFT) & 0xFF);
+
+  SDL_RenderClear(renderer);
+
+  ImGui_ImplSDLRenderer2_RenderDrawData(ImGui::GetDrawData(), renderer);
+  SDL_RenderPresent(renderer);
+
+  // Adjust window size
+  if (show_win) {
+    int min_w = calc_min_width();
+    int w, h;
+    SDL_GetWindowMinimumSize(window, &w, &h);
+    if (w < min_w || h < 400) {
+      SDL_Log("Window width: %d < %d", w, min_w);
+      SDL_SetWindowMinimumSize(window, min_w, 400);
+    }
+  }
+}
+
+int default_input_mode()
+{
+#if defined(DEFAULT_MODE)
+  return DEFAULT_MODE - 1;
+#else
+  return 0;
+#endif
+}
+
+int find_input_mode()
+{
+  // TODO: add support for path from command line
+  std::ifstream file("./RADIO/radio.yml");
+  if (!file) return default_input_mode();
+
+  std::regex re("^stickMode:\\s*(\\d+)");
+  std::string line;
+
+  while (std::getline(file, line)) {
+    std::smatch matches;
+      if (std::regex_search(line, matches, re) && matches.size() > 1) {
+        return std::stoi(matches[1].str());
+      }
+  }
+
+  return default_input_mode();
+}
+
+static void print_usage(const char* path)
+{
+  const char usage[] =
+      "usage: %s [--width width] [--height height] [--storage path] "
+      "[--settings path] [-h | --help]\n";
+
+  printf(usage, basename((char*)path));
+}
+
+static int parse_args(int argc, char* argv[])
+{
+  static struct option long_options[] = {
+      {"help", no_argument, 0, 'h'},
+      {"width", required_argument, 0, 'w'},
+      {"height", required_argument, 0, 'e'},
+      {"storage", required_argument, 0, 's'},
+      {"settings", required_argument, 0, 'c'},
+      {0, 0, 0, 0}};
+
+  int option_index = 0;
+  int c;
+
+  while ((c = getopt_long(argc, argv, "h", long_options, &option_index)) !=
+         -1) {
+    switch (c) {
+      case 'h':
+        print_usage(argv[0]);
+        return 1;
+
+      case 'w':
+        window_width = std::atoi(optarg);
+        break;
+
+      case 'e':
+        window_height = std::atoi(optarg);
+        break;
+
+      case 's':
+        storage_path = std::string(optarg);
+        break;
+
+      case 'c':  // 'c' for config/settings
+        settings_path = std::string(optarg);
+        break;
+
+      case '?':
+        // getopt_long already printed an error message
+        print_usage(argv[0]);
+        return 1;
+
+      default:
+        abort();
+    }
+  }
+
+  // Check for non-option arguments
+  if (optind < argc) {
+    printf("Error: Unexpected arguments: ");
+    while (optind < argc) {
+      printf("%s ", argv[optind++]);
+    }
+    printf("\n");
+    print_usage(argv[0]);
+    return 1;
+  }
+
+  return 0;
+}
+
+int main(int argc, char* argv[])
+{
+  if (parse_args(argc, argv) != 0) {
+    return 1;
+  }
+
+  // Setup SDL
+  if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_GAMECONTROLLER) != 0) {
+    printf("Error: %s\n", SDL_GetError());
+    return -1;
+  }
+
+  simuAudioInit();
+  
+  // From 2.0.18: Enable native IME.
+#ifdef SDL_HINT_IME_SHOW_UI
+  SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");
+#endif
+
+  // Create window with SDL_Renderer graphics context
+  int window_flags = SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI;
+  window = SDL_CreateWindow("EdgeTx Simu", SDL_WINDOWPOS_CENTERED,
+                            SDL_WINDOWPOS_CENTERED, window_width, window_height,
+                            window_flags);
+
+  renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
+  if (renderer == NULL) {
+    SDL_LogError(SDL_LOG_CATEGORY_RENDER, "cannot create SDL_Renderer!");
+    return 0;
+  }
+
+  SDL_RendererInfo info;
+  SDL_GetRendererInfo(renderer, &info);
+  SDL_Log("Current SDL_Renderer: %s", info.name);
+
+  SDL_Surface* icon = LoadImage(_icon_png, sizeof(_icon_png));
+  if (window && icon) {
+    SDL_SetWindowIcon(window, icon);
+  }
+
+  // Setup Dear ImGui context
+  IMGUI_CHECKVERSION();
+  ImGui::CreateContext();
+
+  // Setup Dear ImGui style
+  ImGui::StyleColorsLight();
+  // ImGui::StyleColorsDark();
+
+  // Setup Platform/Renderer backends
+  ImGui_ImplSDL2_InitForSDLRenderer(window, renderer);
+  ImGui_ImplSDLRenderer2_Init(renderer);
+
+  // Create textures for radio screen
+  screen_frame_buffer =
+      SDL_CreateTexture(renderer, SDL_PIXELFORMAT_RGBA8888,
+                        SDL_TEXTUREACCESS_STREAMING, LCD_W, LCD_H);
+
+  if (!screen_frame_buffer) {
+    SDL_Log("Could not create frame buffer textures");
+    return 0;
+  }
+
+  // SDL_SetTextureScaleMode(screen_frame_buffer, SDL_ScaleModeBest);
+  SDL_SetTextureBlendMode(screen_frame_buffer, SDL_BLENDMODE_BLEND);
+
+  // Init gimbal safe position
+  int input_mode = find_input_mode();
+  switch (input_mode) {
+    case 0:
+    case 2:
+      stick_right.pos.y = 1.0f;
+      break;
+    case 1:
+    case 3:
+      stick_left.pos.y = 1.0f;
+      break;
+    default:
+      SDL_Log("Invalid input mode %d", input_mode);
+      return 0;
+  }
+
+  // Init simulation
+  simuInit();
+  simuStart(true, storage_path.c_str(), settings_path.c_str());
+  
+  // Main loop
+  SDL_SetEventFilter([](void*, SDL_Event* event){
+    if (event->type == SDL_WINDOWEVENT &&
+        (event->window.event == SDL_WINDOWEVENT_EXPOSED)) {
+      redraw();
+      return 0;
+    }
+    return 1;
+  }, NULL);
+
+  do {
+    Uint64 start_ts = SDL_GetPerformanceCounter();
+    if (!handleEvents()) break;
+
+    Uint64 end_ts = SDL_GetPerformanceCounter();
+    float elapsedMS =
+      (end_ts - start_ts) / (float)SDL_GetPerformanceFrequency() * 1000.0f;
+
+    // Cap to 60 FPS
+    SDL_Delay(std::max(0,(int32_t)floor(16.666f - elapsedMS)));
+
+  } while(true);
+
+  // App cleanup
+  simuStop();
+
+  // Cleanup
+  ImGui_ImplSDLRenderer2_Shutdown();
+  ImGui_ImplSDL2_Shutdown();
+  ImGui::DestroyContext();
+
+  SDL_DestroyTexture(screen_frame_buffer);
+  SDL_DestroyRenderer(renderer);
+  SDL_DestroyWindow(window);
+  SDL_FreeSurface(icon);
+  SDL_CloseAudio();
+  SDL_Quit();
+  
+  return 0;
+}
+
+uint16_t simu_get_analog(uint8_t idx)
+{
+  auto max_sticks = adcGetMaxInputs(ADC_INPUT_MAIN);
+  if (idx < max_sticks) {
+    switch(idx) {
+    case 0: return stick_left.pos.x * 4096;
+    case 1: return (1.0 - stick_left.pos.y) * 4096;
+    case 2: return (1.0 - stick_right.pos.y) * 4096;
+    case 3: return stick_right.pos.x * 4096;
+    }
+  }
+
+  idx -= max_sticks;
+
+  auto max_pots = adcGetMaxInputs(ADC_INPUT_FLEX);
+  if (idx < max_pots) {
+    switch(getPotType(idx)){
+    case FLEX_POT:
+    case FLEX_POT_CENTER:
+    case FLEX_SLIDER:
+      return uint16_t(((uint32_t(pots[idx]) + 100) * 4096) / 200);
+    case FLEX_MULTIPOS:
+      return (uint32_t(pots[idx]) * 4096) / 5;
+    }
+  }
+
+  // idx -= max_pots;
+
+  // auto max_axes = adcGetMaxInputs(ADC_INPUT_AXIS);
+  // if (idx < max_axes) return 0;
+
+  // probably RTC_BAT
+  return 0;
+}
@@ -127,6 +127,8 @@ void simuInit()

  // Init ADC driver callback
  adcInit(&simu_adc_driver);
+  // Switches
+  switchInit();
 }

 bool keysStates[MAX_KEYS] = { false };
@@ -205,12 +207,6 @@ void simuStart(bool tests, const char * sdPath, const char * settingsPath)
  }
 #endif

-#if defined(SIMU_EXCEPTIONS)
-  signal(SIGFPE, sig);
-  signal(SIGSEGV, sig);
-  try {
-#endif
-
  // Init LCD callbacks
  lcdInit();

@@ -228,12 +224,6 @@ void simuStart(bool tests, const char * sdPath, const char * settingsPath)
 #endif

  simu_running = true;
-
-#if defined(SIMU_EXCEPTIONS)
-  }
-  catch (...) {
-  }
-#endif
 }

 extern task_handle_t mixerTaskId;
@@ -250,130 +240,14 @@ void simuStop()
  simu_shutdown = true;
  task_shutdown_all();

-#if defined(SIMU_AUDIO)
-  stopAudio();
-#endif
-
  simu_running = false;
 }

-struct SimulatorAudio {
-  int volumeGain;
-  int currentVolume;
-  int16_t leftoverData[AUDIO_BUFFER_SIZE];
-  int leftoverLen;
-} simuAudio;
-
 bool simuIsRunning()
 {
  return simu_running;
 }

-void audioConsumeCurrentBuffer()
-{
-}
-
-void audioSetVolume(uint8_t volume)
-{
-  simuAudio.currentVolume = 127 * volume * simuAudio.volumeGain / VOLUME_LEVEL_MAX / 10;
-  // TRACE_SIMPGMSPACE("setVolume(): in: %u, out: %u", volume, simuAudio.currentVolume);
-}
-
-#if defined(SIMU_AUDIO)
-void copyBuffer(void* dest, const int16_t* buff, unsigned samples)
-{
-  int16_t* i16_dst = (int16_t*)dest;
-  for (unsigned i = 0; i < samples; i++) {
-    int32_t sample = (((int32_t)buff[i] * (int32_t)simuAudio.currentVolume) / 127);
-    if (sample > INT16_MAX) sample = INT16_MAX;
-    else if (sample < INT16_MIN) sample = INT16_MIN;
-    *(i16_dst++) = (int16_t)sample;
-  }
-}
-
-void fillAudioBuffer(void *udata, Uint8 *stream, int len)
-{
-  SDL_memset(stream, 0, len);
-
-  if (simuAudio.leftoverLen) {
-    int len1 = min(len/2, simuAudio.leftoverLen);
-    copyBuffer(stream, simuAudio.leftoverData, len1);
-    len -= len1*2;
-    stream += len1*2;
-    simuAudio.leftoverLen -= len1;
-    // putchar('l');
-    if (simuAudio.leftoverLen) return;		// buffer fully filled
-  }
-
-  if (audioQueue.buffersFifo.filledAtleast(len / (AUDIO_BUFFER_SIZE * 2) + 1)) {
-    while (true) {
-      const AudioBuffer* nextBuffer =
-          audioQueue.buffersFifo.getNextFilledBuffer();
-      if (nextBuffer) {
-        if (len >= nextBuffer->size * 2) {
-          copyBuffer(stream, nextBuffer->data, nextBuffer->size);
-          stream += nextBuffer->size * 2;
-          len -= nextBuffer->size * 2;
-          // putchar('+');
-          audioQueue.buffersFifo.freeNextFilledBuffer();
-        } else {
-          // partial
-          copyBuffer(stream, nextBuffer->data, len / 2);
-          simuAudio.leftoverLen = (nextBuffer->size - len / 2);
-          memcpy(simuAudio.leftoverData, &nextBuffer->data[len / 2],
-                 simuAudio.leftoverLen * 2);
-          len = 0;
-          // putchar('p');
-          audioQueue.buffersFifo.freeNextFilledBuffer();
-          break;
-        }
-      } else {
-        break;
-      }
-    }
-  }
-
-  // fill the rest of buffer with silence
-  if (len > 0) {
-    SDL_memset(stream, 0x8000, len);  // make sure this is silence.
-  }
-}
-
-int startAudio(int volumeGain)
-{
-  simuAudio = {
-    .volumeGain = volumeGain,
-    .leftoverLen = 0,
-  };
-
-  TRACE("startAudioThread(%d)", volumeGain);
-  audioSetVolume(VOLUME_LEVEL_DEF);
-
-  /* Set the audio format */
-  SDL_AudioSpec desired = {
-    .freq = AUDIO_SAMPLE_RATE,
-    .format = AUDIO_S16SYS,
-    .channels = 1,
-    .samples = AUDIO_BUFFER_SIZE * 2,
-    .callback = fillAudioBuffer,
-    .userdata = nullptr,
-  };
-
-  SDL_AudioSpec obtained;
-  if ( SDL_OpenAudio(&desired, &obtained) < 0 ) {
-    fprintf(stderr, "Couldn't open audio: %s\n", SDL_GetError());
-    return -1;
-  }
-  SDL_PauseAudio(0);
-  return 0;
-}
-
-void stopAudio()
-{
-  SDL_CloseAudio();
-}
-#endif // #if defined(SIMU_AUDIO)
-
 #if !defined(COLORLCD)
 void lcdSetRefVolt(uint8_t val)
 {
@@ -617,6 +491,12 @@ const etx_serial_port_t* auxSerialGetPort(int port_nr)
 struct TouchState simTouchState = {};
 bool simTouchOccured = false;

+bool touchPanelInit()
+{
+  simTouchState.x = simTouchState.y = 0;
+  return true;
+}
+
 bool touchPanelEventOccured()
 {
  if(simTouchOccured)
@@ -627,6 +507,20 @@ bool touchPanelEventOccured()
  return false;
 }

+void touchPanelDown(short x, short y)
+{
+  simTouchState.x = x;
+  simTouchState.y = y;
+  simTouchState.event = TE_DOWN;
+  simTouchOccured = true;
+}
+
+void touchPanelUp()
+{
+  simTouchState.event = TE_UP;
+  simTouchOccured = true;
+}
+
 struct TouchState touchPanelRead()
 {
  struct TouchState st = simTouchState;
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) EdgeTX
+ *
+ * Based on code named
+ *   opentx - https://github.com/opentx/opentx
+ *   th9x - http://code.google.com/p/th9x
+ *   er9x - http://code.google.com/p/er9x
+ *   gruvin9x - http://code.google.com/p/gruvin9x
+ *
+ * License GPLv2: http://www.gnu.org/licenses/gpl-2.0.html
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#pragma once
+
+#if defined(COLORLCD)
+  #include "gui/colorlcd/lcd.h"
+#endif
+
+#include "targets/simu/simulcd.h"
+#include "hal/adc_driver.h"
+#include "hal/rotary_encoder.h"
+
+// 10ms ISR
+void per10ms();
+
+// touch panel methods
+bool touchPanelInit();
+void touchPanelDown(short x, short y);
+void touchPanelUp();
@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) EdgeTX
+ *
+ * Based on code named
+ *   opentx - https://github.com/opentx/opentx
+ *   th9x - http://code.google.com/p/th9x
+ *   er9x - http://code.google.com/p/er9x
+ *   gruvin9x - http://code.google.com/p/gruvin9x
+ *
+ * License GPLv2: http://www.gnu.org/licenses/gpl-2.0.html
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#include "audio.h"
+#include "simuaudio.h"
+
+#include <stdint.h>
+#include <SDL.h>
+
+#define SIMU_AUDIO_FMT AUDIO_S16SYS
+
+static SDL_AudioDeviceID _sdl_audio_device = 0;
+
+#if !defined(SOFTWARE_VOLUME)
+
+static Uint8 _tmp_buf[AUDIO_BUFFER_SIZE * sizeof(audio_data_t)];
+static int _simu_volume = 0;
+
+void audioSetVolume(uint8_t volume)
+{
+  _simu_volume = SDL_MIX_MAXVOLUME * volume / VOLUME_LEVEL_MAX;
+}
+
+static void _fill_with_silence(Uint8* dst, uint32_t len)
+{
+  auto p = (audio_data_t*)dst;
+  auto end = p + len / sizeof(audio_data_t);
+
+  while (p < end) {
+    *p++ = AUDIO_DATA_SILENCE;
+  }
+}
+
+#endif
+
+void audioConsumeCurrentBuffer()
+{
+  while(true) {
+    auto nextBuffer = audioQueue.buffersFifo.getNextFilledBuffer();
+    if (!nextBuffer) return;
+
+    auto data = (const Uint8*)nextBuffer->data;
+    uint32_t len = nextBuffer->size * sizeof(audio_data_t);
+
+#if !defined(SOFTWARE_VOLUME)
+    assert(len <= sizeof(_tmp_buf));
+    _fill_with_silence(_tmp_buf, len);
+
+    SDL_MixAudioFormat(_tmp_buf, data, SIMU_AUDIO_FMT, len, _simu_volume);
+    data = _tmp_buf;
+#endif
+
+    SDL_QueueAudio(_sdl_audio_device, data, len);
+    audioQueue.buffersFifo.freeNextFilledBuffer();
+  }
+}
+
+bool simuAudioInit()
+{
+  SDL_AudioSpec wanted = {
+    .freq = AUDIO_SAMPLE_RATE,
+    .format = SIMU_AUDIO_FMT,
+    .channels = 1,
+    .silence = 0,
+    .samples = 1024,
+  };
+
+  SDL_AudioSpec have;
+  _sdl_audio_device = SDL_OpenAudioDevice(0, 0, &wanted, &have, 0);
+  if (!_sdl_audio_device) {
+    SDL_Log("Couldn't open audio: %s\n", SDL_GetError());
+    return false;
+  }
+
+  SDL_PauseAudioDevice(_sdl_audio_device, 0);
+  return true;
+}
+
+void simuAudioDeInit()
+{
+  if(_sdl_audio_device > 0) {
+    SDL_CloseAudioDevice(_sdl_audio_device);
+    _sdl_audio_device = 0;
+  }
+}
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) EdgeTX
+ *
+ * Based on code named
+ *   opentx - https://github.com/opentx/opentx
+ *   th9x - http://code.google.com/p/th9x
+ *   er9x - http://code.google.com/p/er9x
+ *   gruvin9x - http://code.google.com/p/gruvin9x
+ *
+ * License GPLv2: http://www.gnu.org/licenses/gpl-2.0.html
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#pragma once
+
+bool simuAudioInit();
+void simuAudioDeInit();
@@ -20,272 +20,102 @@
 */

 #if defined(SIMU_DISKIO)
-#include "edgetx.h"
-#include "ff.h"
-#include "diskio.h"
-#include <time.h>
+#include "hal/fatfs_diskio.h"
+
 #include <stdio.h>
-#include <sys/stat.h>
+#include <string.h>
+#include <errno.h>

-FILE * diskImage = 0;
+extern const diskio_driver_t simu_diskio_driver;

-bool _g_FATFS_init = false;
+static FILE* disk_image = nullptr;

-RTOS_MUTEX_HANDLE ioMutex;
+// create FS with: mkdosfs -n SDCARD -S 512 -C sdcard.img 524288
+static const char* image_path = "sdcard.img";

-int ff_cre_syncobj (BYTE vol, FF_SYNC_t* sobj) /* Create a sync object */
+static int _seek(DWORD sector)
 {
-  pthread_mutex_init(&ioMutex, 0);
-  return 1;
-}
-
-int ff_req_grant (FF_SYNC_t sobj)        /* Lock sync object */
-{
-  pthread_mutex_lock(&ioMutex);
-  return 1;
-}
-
-void ff_rel_grant (FF_SYNC_t sobj)        /* Unlock sync object */
-{
-  pthread_mutex_unlock(&ioMutex);
-}
-
-int ff_del_syncobj (FF_SYNC_t sobj)        /* Delete a sync object */
-{
-  pthread_mutex_destroy(&ioMutex);
-  return 1;
-}
-
-DWORD get_fattime (void)
-{
-  time_t tim = time(0);
-  const struct tm * t = gmtime(&tim);
-
-  /* Pack date and time into a DWORD variable */
-  return ((DWORD)(t->tm_year - 80) << 25)
-    | ((uint32_t)(t->tm_mon+1) << 21)
-    | ((uint32_t)t->tm_mday << 16)
-    | ((uint32_t)t->tm_hour << 11)
-    | ((uint32_t)t->tm_min << 5)
-    | ((uint32_t)t->tm_sec >> 1);
-}
-
-unsigned int noDiskStatus = 0;
-
-void traceDiskStatus()
-{
-  if (noDiskStatus > 0) {
-    TRACE_SIMPGMSPACE("disk_status() called %d times", noDiskStatus);
-    noDiskStatus = 0;
+  if (!disk_image) {
+    fprintf(stderr, "disk image is NULL\n");
+    return -1;
  }
+
+  if (fseek(disk_image, sector * 512, SEEK_SET) != 0) {
+    fprintf(stderr, "fseek failed: %s\n", strerror(errno));
+    return -1;
+  }
+
+  return 0;
 }

-DSTATUS disk_initialize (BYTE pdrv)
+static DSTATUS simu_disk_initialize(BYTE lun)
 {
-  traceDiskStatus();
-  TRACE_SIMPGMSPACE("disk_initialize(%u)", pdrv);
-  diskImage = fopen("sdcard.image", "rb+");
-  return diskImage ? (DSTATUS)0 : (DSTATUS)STA_NODISK;
-}
+  if (!image_path) return STA_NODISK;
+  disk_image = fopen(image_path, "rb+");
+  if (!disk_image) {
+    fprintf(stderr, "could not open disk image: %s\n", strerror(errno));
+    return STA_NODISK;
+  }

-DSTATUS disk_status (BYTE pdrv)
-{
-  ++noDiskStatus;
-  // TRACE_SIMPGMSPACE("disk_status(%u)", pdrv);
-  return (DSTATUS)0;
-}
-
-DRESULT disk_read (BYTE pdrv, BYTE* buff, DWORD sector, UINT count)
-{
-  if (diskImage == 0) return RES_NOTRDY;
-  traceDiskStatus();
-  TRACE_SIMPGMSPACE("disk_read(%u, %p, %u, %u)", pdrv, buff, sector, count);
-  fseek(diskImage, sector*512, SEEK_SET);
-  fread(buff, count, 512, diskImage);
  return RES_OK;
 }

-DRESULT disk_write (BYTE pdrv, const BYTE* buff, DWORD sector, UINT count)
+static DSTATUS simu_disk_status(BYTE lun) { return RES_OK; }
+
+static DRESULT simu_disk_read(BYTE lun, BYTE* buff, DWORD sector, UINT count)
 {
-  if (diskImage == 0) return RES_NOTRDY;
-  traceDiskStatus();
-  TRACE_SIMPGMSPACE("disk_write(%u, %p, %u, %u)", pdrv, buff, sector, count);
-  fseek(diskImage, sector*512, SEEK_SET);
-  fwrite(buff, count, 512, diskImage);
+  if (_seek(sector) != 0) return RES_ERROR;
+  fprintf(stderr, "# R %d/%d\n", sector, count);
+  fread(buff, 512, count, disk_image);
  return RES_OK;
 }

-DRESULT disk_ioctl (BYTE pdrv, BYTE cmd, void* buff)
+static DRESULT simu_disk_write(BYTE lun, const BYTE* buff, DWORD sector, UINT count)
 {
-  if (diskImage == 0) return RES_NOTRDY;
-  traceDiskStatus();
-  TRACE_SIMPGMSPACE("disk_ioctl(%u, %u, %p)", pdrv, cmd, buff);
-  if (pdrv) return RES_PARERR;
+  if (_seek(sector) != 0) return RES_ERROR;
+  fprintf(stderr, "# W %d/%d\n", sector, count);
+  fwrite(buff, 512, count, disk_image);
+  return RES_OK;
+}

-  DRESULT res;
-  BYTE *ptr = (BYTE *)buff;
-
-  if (cmd == CTRL_POWER) {
-    switch (*ptr) {
-      case 0:         /* Sub control code == 0 (POWER_OFF) */
-        res = RES_OK;
-        break;
-      case 1:         /* Sub control code == 1 (POWER_ON) */
-        res = RES_OK;
-        break;
-      case 2:         /* Sub control code == 2 (POWER_GET) */
-        *(ptr+1) = (BYTE)1;  /* fake powered */
-        res = RES_OK;
-        break;
-      default :
-        res = RES_PARERR;
-    }
-    return res;
-  }
+static DRESULT simu_disk_ioctl(BYTE lun, BYTE cmd, void* buff)
+{
+  if (!disk_image) return RES_NOTRDY;

+  DRESULT res = RES_OK;
  switch(cmd) {
-/* Generic command (Used by FatFs) */
-    case CTRL_SYNC :     /* Complete pending write process (needed at _FS_READONLY == 0) */
-      break;
-
-    case GET_SECTOR_COUNT: /* Get media size (needed at _USE_MKFS == 1) */
-      {
-        struct stat buf;
-        if (stat("sdcard.image", &buf) == 0) {
-          DWORD noSectors  = buf.st_size / 512;
-          *(DWORD*)buff = noSectors;
-          TRACE_SIMPGMSPACE("disk_ioctl(GET_SECTOR_COUNT) = %u", noSectors);
-          return RES_OK;
-        }
-        return RES_ERROR;
+    case GET_SECTOR_COUNT:
+      if (fseek(disk_image, 0, SEEK_END) == 0) {
+        long sectors = ftell(disk_image) / 512L;
+        fprintf(stderr, "# S %ld\n", sectors);
+        *((DWORD*)buff) = (DWORD)(sectors);
+      } else {
+        fprintf(stderr, "fseek failed: %s\n", strerror(errno));
+        res = RES_ERROR;
      }
+      break;

-    case GET_SECTOR_SIZE: /* Get sector size (needed at _MAX_SS != _MIN_SS) */
-      TRACE_SIMPGMSPACE("disk_ioctl(GET_SECTOR_SIZE) = 512");
+    case GET_SECTOR_SIZE:
      *(WORD*)buff = 512;
-      res = RES_OK;
      break;

-    case GET_BLOCK_SIZE : /* Get erase block size (needed at _USE_MKFS == 1) */
+    case GET_BLOCK_SIZE:
      *(WORD*)buff = 512 * 4;
-      res = RES_OK;
      break;

-    case CTRL_TRIM : /* Inform device that the data on the block of sectors is no longer used (needed at _USE_TRIM == 1) */
-      break;
-
-/* Generic command (Not used by FatFs) */
-    case CTRL_LOCK : /* Lock/Unlock media removal */
-    case CTRL_EJECT: /* Eject media */
-    case CTRL_FORMAT: /* Create physical format on the media */
-      return RES_PARERR;
-
-
-/* MMC/SDC specific ioctl command */
-    // case MMC_GET_TYPE    10  /* Get card type */
-    // case MMC_GET_CSD     11  /* Get CSD */
-    // case MMC_GET_CID     12  /* Get CID */
-    // case MMC_GET_OCR     13  /* Get OCR */
-    // case MMC_GET_SDSTAT    14  /* Get SD status */
-
-/* ATA/CF specific ioctl command */
-    // case ATA_GET_REV     20  /* Get F/W revision */
-    // case ATA_GET_MODEL   21  /* Get model name */
-    // case ATA_GET_SN      22  /* Get serial number */
    default:
-      return RES_PARERR;
+      break;
  }
-  return RES_OK;
+
+  return res;
 }

-void sdInit(void)
-{
-  // ioMutex = CoCreateMutex();
-  // if (ioMutex >= CFG_MAX_MUTEX ) {
-  //   // sd error
-  //   return;
-  // }
-
-  if (f_mount(&g_FATFS_Obj, "", 1) == FR_OK) {
-    // call sdGetFreeSectors() now because f_getfree() takes a long time first time it's called
-    sdGetFreeSectors();
-
-#if defined(LOG_TELEMETRY)
-    f_open(&g_telemetryFile, LOGS_PATH "/telemetry.log", FA_OPEN_ALWAYS | FA_WRITE);
-    if (f_size(&g_telemetryFile) > 0) {
-      f_lseek(&g_telemetryFile, f_size(&g_telemetryFile)); // append
-    }
-#endif
-
-#if defined(LOG_BLUETOOTH)
-    f_open(&g_bluetoothFile, LOGS_PATH "/bluetooth.log", FA_OPEN_ALWAYS | FA_WRITE);
-    if (f_size(&g_bluetoothFile) > 0) {
-      f_lseek(&g_bluetoothFile, f_size(&g_bluetoothFile)); // append
-    }
-#endif
-  }
-  else {
-    TRACE_SIMPGMSPACE("f_mount() failed");
-  }
-}
-
-void sdDone()
-{
-  if (sdMounted()) {
-    audioQueue.stopSD();
-#if defined(LOG_TELEMETRY)
-    f_close(&g_telemetryFile);
-#endif
-#if defined(LOG_BLUETOOTH)
-    f_close(&g_bluetoothFile);
-#endif
-    f_mount(NULL, "", 0); // unmount SD
-  }
-}
-
-void sdMount()
-{
-  TRACE("sdMount");
-  
-  diskCache.clear();
-  
-  if (f_mount(&g_FATFS_Obj, "", 1) == FR_OK) {
-    // call sdGetFreeSectors() now because f_getfree() takes a long time first time it's called
-    _g_FATFS_init = true;
-    sdGetFreeSectors();
-
-#if defined(LOG_TELEMETRY)
-    f_open(&g_telemetryFile, LOGS_PATH "/telemetry.log", FA_OPEN_ALWAYS | FA_WRITE);
-    if (f_size(&g_telemetryFile) > 0) {
-      f_lseek(&g_telemetryFile, f_size(&g_telemetryFile)); // append
-    }
-#endif
-
-#if defined(LOG_BLUETOOTH)
-    f_open(&g_bluetoothFile, LOGS_PATH "/bluetooth.log", FA_OPEN_ALWAYS | FA_WRITE);
-    if (f_size(&g_bluetoothFile) > 0) {
-      f_lseek(&g_bluetoothFile, f_size(&g_bluetoothFile)); // append
-    }
-#endif
-  }
-  else {
-    TRACE("f_mount() failed");
-  }
-}
-
-uint32_t sdMounted()
-{
-  return _g_FATFS_init && (g_FATFS_Obj.fs_type != 0);
-}
-
-uint32_t sdIsHC()
-{
-  return sdGetSize() > 2000000;
-}
-
-uint32_t sdGetSpeed()
-{
-  return 330000;
-}
+const diskio_driver_t simu_diskio_driver = {
+  .initialize = simu_disk_initialize,
+  .status = simu_disk_status,
+  .read = simu_disk_read,
+  .write = simu_disk_write,
+  .ioctl = simu_disk_ioctl,
+};

 #endif // #if defined(SIMU_DISKIO)
@@ -87,15 +87,14 @@ std::string fixPathDelimiters(const char * path)

 void simuFatfsSetPaths(const char * sdPath, const char * settingsPath)
 {
-  if (sdPath) {
+  if (sdPath && strlen(sdPath) > 0) {
    simuSdDirectory = removeTrailingPathDelimiter(fixPathDelimiters(sdPath));
-  }
-  else {
+  } else if (simuSdDirectory.empty()) {
    char buff[1024];
-    f_getcwd(buff, sizeof(buff)-1);
+    f_getcwd(buff, sizeof(buff) - 1);
    simuSdDirectory = removeTrailingPathDelimiter(fixPathDelimiters(buff));
  }
-  if (settingsPath) {
+  if (settingsPath && strlen(settingsPath) > 0) {
    simuSettingsDirectory = removeTrailingPathDelimiter(fixPathDelimiters(settingsPath));
  }
  TRACE_SIMPGMSPACE("simuFatfsSetPaths(): simuSdDirectory: \"%s\"", simuSdDirectory.c_str());
@@ -57,51 +57,7 @@ static pixel_t _LCD_BUF2[DISPLAY_BUFFER_SIZE] __SDRAM;

 pixel_t* simuLcdBuf = _LCD_BUF1;
 pixel_t* simuLcdBackBuf = _LCD_BUF2;
-#if 0
-// Copy 2 pixels at once to speed up a little
-static void _copy_rotate_180(uint16_t* dst, uint16_t* src, const rect_t& copy_area)
-{
-  coord_t x1 = LCD_W - copy_area.w - copy_area.x;
-  coord_t y1 = LCD_H - copy_area.h - copy_area.y;

-  auto total = copy_area.w * copy_area.h;
-  uint16_t* px_src = src + total - 2;
-
-  auto px_dst = dst + y1 * LCD_W + x1;
-  for (auto line = 0; line < copy_area.h; line++) {
-
-    auto line_end = px_dst + (copy_area.w & ~1);
-    while (px_dst != line_end) {
-      uint32_t* px2_src = (uint32_t*)px_src;
-      uint32_t* px2_dst = (uint32_t*)px_dst;
-
-      uint32_t px = ((*px2_src & 0xFFFF0000) >> 16) | ((*px2_src & 0xFFFF) << 16);
-      *px2_dst = px;
-
-      px_src -= 2;
-      px_dst += 2;
-    }
-
-    if (copy_area.w & 1) {
-      *(px_dst++) = *(px_src+1);
-      px_src--;
-    }
-
-    px_dst += LCD_W - copy_area.w;
-  }
-}
-
-static void _rotate_area_180(lv_area_t& area)
-{
-  lv_coord_t tmp_coord;
-  tmp_coord = area.y2;
-  area.y2 = LCD_H - area.y1 - 1;
-  area.y1 = LCD_H - tmp_coord - 1;
-  tmp_coord = area.x2;
-  area.x2 = LCD_W - area.x1 - 1;
-  area.x1 = LCD_W - tmp_coord - 1;
-}
-#endif
 static void _copy_screen_area(uint16_t* dst, uint16_t* src, const lv_area_t& copy_area)
 {
  lv_coord_t x1 = copy_area.x1;
@@ -150,8 +106,6 @@ static void simuRefreshLcd(lv_disp_drv_t * disp_drv, uint16_t *buffer, const rec
  simuLcdRefresh = true;

 #else
-  // // copy / rotate current area
-  // _copy_rotate_180(simuLcdBackBuf, buffer, copy_area);
  _copy_area(simuLcdBackBuf, buffer, copy_area);
  
  if (lv_disp_flush_is_last(disp_drv)) {
@@ -22,11 +22,12 @@
 #include "hal/switch_driver.h"
 #include "definitions.h"
 #include "myeeprom.h"
-
-#include <stdlib.h>
-#include <assert.h>
 #include "switches.h"

+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
 struct hw_switch_def {
  const char*  name;
  SwitchHwType type;
@@ -34,7 +35,7 @@ struct hw_switch_def {

 #include "simu_switches.inc"

-int8_t switchesStates[MAX_SWITCHES] = { -1 };
+int8_t switchesStates[MAX_SWITCHES] = { 0 };

 void simuSetSwitch(uint8_t swtch, int8_t state)
 {
@@ -42,7 +43,9 @@ void simuSetSwitch(uint8_t swtch, int8_t state)
  switchesStates[swtch] = state;
 }

-void boardInitSwitches() {}
+void boardInitSwitches() {
+  memset(switchesStates, -1, sizeof(switchesStates));
+}

 static uint8_t get_switch_index(uint8_t cat, uint8_t idx)
 {
@@ -0,0 +1,222 @@
+/*
+ * Copyright (C) EdgeTX
+ *
+ * Based on code named
+ *   opentx - https://github.com/opentx/opentx
+ *   th9x - http://code.google.com/p/th9x
+ *   er9x - http://code.google.com/p/er9x
+ *   gruvin9x - http://code.google.com/p/gruvin9x
+ *
+ * License GPLv2: http://www.gnu.org/licenses/gpl-2.0.html
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#include "widgets.h"
+
+#include <imgui.h>
+#include <algorithm>
+#include <cmath>
+
+#define _PI_ 3.14159265358979323846f
+
+static inline float _clamp(float f)
+{
+  return (f < 0.0) ? 0.0 : (f > 1.0) ? 1.0 : f;
+}
+
+static inline void adjust_gimbal(float& pos)
+{
+  if (pos != 0.5f) {
+    auto diff = 0.5 - pos;
+    if (std::abs(diff) > 0.01) {
+      pos += diff / 10;
+    } else {
+      pos = 0.5;
+    }
+  }
+}
+
+static void draw_tick(const ImVec2& center, ImU32 col, float angle,
+                      float start, float end, float thickness)
+{
+  auto angle_cos = std::cos(angle);
+  auto angle_sin = std::sin(angle);
+
+  ImDrawList* draw_list = ImGui::GetWindowDrawList();
+  draw_list->AddLine({center.x + angle_cos * end, center.y + angle_sin * end},
+                     {center.x + angle_cos * start, center.y + angle_sin * start},
+                     col, thickness);
+}
+
+static void draw_gimbal_frame(const ImVec2& p0, const ImVec2& p1, float rounding, float thickness)
+{
+  ImDrawList* draw_list = ImGui::GetWindowDrawList();
+  auto bg_col = ImGui::GetColorU32(ImGuiCol_FrameBg);
+  draw_list->AddRectFilled(p0, p1, bg_col, rounding,
+                           ImDrawFlags_RoundCornersAll);
+
+  auto frame_col = ImGui::GetColorU32(ImGuiCol_Border);
+  draw_list->AddRect(p0, p1, frame_col, rounding,
+                     ImDrawFlags_RoundCornersAll, thickness);
+
+  float gimbal_mid = (p1.x - p0.x) / 2.0;
+  float circle_radius = gimbal_mid * 0.75;
+  ImVec2 center = {p0.x + gimbal_mid, p0.y + gimbal_mid};
+
+  float circle_thickness = thickness * 1.8f;
+  float inner_radius = circle_radius - circle_thickness / 2.0;
+
+  draw_list->AddCircle(center, circle_radius, frame_col, 0, thickness * 1.8f);
+
+  for (float deg = 0.0f; deg < 360.0f; deg += 10.0f) {
+    float angle = _PI_ * deg / 180.0f;
+    draw_tick(center, IM_COL32_WHITE, angle,
+              circle_radius - circle_thickness * 0.3f,
+              circle_radius + circle_thickness * 0.3f,
+              circle_thickness * 0.2f);
+  }
+
+  for (float deg = 0.0f; deg < 360.0f; deg += 90.0f) {
+    float angle = _PI_ * deg / 180.0f;
+    draw_tick(center, frame_col, angle,
+              inner_radius, circle_thickness, circle_thickness * 0.2f);
+  }
+}
+
+void SingleGimbal(const char* name, GimbalState& gs)
+{
+  const auto gimbal_width = 120.0f;
+  const auto border_rounding = 12.0f;
+  const auto border_thickness = 6.0f;
+  const auto default_dot_radius = 12.0f;
+
+  ImGui::InvisibleButton(name, ImVec2(gimbal_width, gimbal_width));
+
+  auto p0 = ImGui::GetItemRectMin();
+  p0.x += 6.0f;
+  p0.y += 6.0f;
+
+  auto p1 = ImGui::GetItemRectMax();
+  p1.x -= 6.0f;
+  p1.y -= 6.0f;
+
+  draw_gimbal_frame(p0, p1, border_rounding, border_thickness);
+  
+  float dot_radius = default_dot_radius;
+  ImU32 col = ImGui::GetColorU32(ImGuiCol_Button);
+  if (ImGui::IsItemActive()) {
+    dot_radius += 1.5;
+    col = ImGui::GetColorU32(ImGuiCol_ButtonActive);
+  } else if (ImGui::IsItemHovered()) {
+    col = ImGui::GetColorU32(ImGuiCol_ButtonHovered);
+  }
+
+  float eff_width = gimbal_width - 12.0f - 2.0 * default_dot_radius;
+  float half_width = (gimbal_width - 12.0f) / 2.0;
+
+  if (ImGui::IsItemActive()) {
+    const auto& io = ImGui::GetIO();
+    ImVec2 mouse_pos(io.MousePos.x - p0.x, io.MousePos.y - p0.y);
+    gs.pos.x = _clamp((mouse_pos.x - half_width) / eff_width + 0.5);
+    gs.pos.y = _clamp((mouse_pos.y - half_width) / eff_width + 0.5);
+  } else {
+    adjust_gimbal(gs.pos.x);
+    if (!gs.lock_y) adjust_gimbal(gs.pos.y);
+  }
+
+  ImVec2 dot_center(p0.x + eff_width * (gs.pos.x - 0.5) + half_width,
+                    p0.y + eff_width * (gs.pos.y - 0.5) + half_width);
+
+  // Make color opaque
+  col |= IM_COL32_BLACK;
+  ImGui::GetWindowDrawList()->AddCircle(dot_center, dot_radius, col, 0, dot_radius - 1.0);
+}
+
+void GimbalPair(const char* str_id, GimbalState& left, GimbalState& right)
+{
+  ImGui::PushID(str_id);
+  ImGui::BeginGroup();
+
+  SingleGimbal("#g-left", left);
+  ImGui::SameLine();
+  SingleGimbal("#g-right", right);
+
+  ImGui::EndGroup();
+  ImGui::PopID();
+}
+
+void SimuScreen(const ScreenDesc& desc, ImTextureID screen_img, ImVec2 size,
+                ImU32 bg_col, ImU32 overlay_col)
+{
+  ImGui::InvisibleButton("#simu-screen", size);
+  if (!ImGui::IsItemVisible()) return;
+
+  ImVec2 p_min = ImGui::GetItemRectMin();
+  ImVec2 p_max = ImGui::GetItemRectMax();
+
+  ImDrawList* draw_list = ImGui::GetWindowDrawList();
+  if (bg_col != IM_COL32_BLACK_TRANS) {
+    draw_list->AddRectFilled(p_min, p_max, bg_col);
+  }
+  draw_list->AddImage(screen_img, p_min, p_max);
+
+  if (desc.is_dot_matrix) {
+    float dx = size.x / float(desc.width);
+    float thickness = dx / 50.0;
+    auto col = bg_col & 0x80FFFFFF;
+    for (int x = 1; x < desc.width; x++) {
+      ImVec2 p1 = { p_min.x + x * size.x / float(desc.width), p_min.y };
+      ImVec2 p2 = { p1.x, p_min.y + size.y - 1 };
+      draw_list->AddLine(p1, p2, col, thickness);
+    }
+    for (int y = 1; y < desc.height; y++) {
+      ImVec2 p1 = { p_min.x, p_min.y + y * size.y / float(desc.height) };
+      ImVec2 p2 = { p_min.x + size.x - 1, p1.y };
+      draw_list->AddLine(p1, p2, col, thickness);
+    }
+  }
+
+  if (overlay_col != IM_COL32_BLACK_TRANS) {
+    draw_list->AddRectFilled(p_min, p_max, overlay_col);
+  }
+}
+
+bool SimuScreenMouseEvent(const ScreenDesc& desc, ScreenMouseEvent& event)
+{
+  bool active = ImGui::IsItemActive() && ImGui::IsMouseDown(ImGuiMouseButton_Left);
+  bool deactivated = ImGui::IsItemDeactivated() && ImGui::IsMouseReleased(ImGuiMouseButton_Left);
+
+  if (active || deactivated) {
+
+    auto size = ImGui::GetItemRectSize();
+    float scale_x = float(desc.width) / size.x;
+    float scale_y = float(desc.height) / size.y;
+    
+    ImGuiIO& io = ImGui::GetIO();
+    auto p0 = ImGui::GetItemRectMin();
+
+    const ImVec2 mouse_pos(io.MousePos.x - p0.x, io.MousePos.y - p0.y);
+    const ImVec2 scaled_pos(mouse_pos.x * scale_x, mouse_pos.y * scale_y);
+
+    if (active) {
+      event.type = ScreenMouseEventType::MouseDown;
+    } else {
+      event.type = ScreenMouseEventType::MouseUp;
+    }
+ 
+    event.pos_x = (int)std::round(scaled_pos.x);
+    event.pos_y = (int)std::round(scaled_pos.y);
+
+    return true;
+  }
+
+  return false;
+}
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) EdgeTX
+ *
+ * Based on code named
+ *   opentx - https://github.com/opentx/opentx
+ *   th9x - http://code.google.com/p/th9x
+ *   er9x - http://code.google.com/p/er9x
+ *   gruvin9x - http://code.google.com/p/gruvin9x
+ *
+ * License GPLv2: http://www.gnu.org/licenses/gpl-2.0.html
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#pragma once
+
+#include <imgui.h>
+
+struct GimbalState {
+  ImVec2 pos;
+  bool   lock_y;
+};
+
+struct ScreenDesc {
+  int width;
+  int height;
+  bool is_dot_matrix;
+};
+
+enum class ScreenMouseEventType {
+  MouseDown,
+  MouseUp,
+};
+
+struct ScreenMouseEvent {
+  ScreenMouseEventType type;
+  int pos_x;
+  int pos_y;
+};
+
+void GimbalPair(const char* str_id, GimbalState& left, GimbalState& right);
+void SimuScreen(const ScreenDesc& desc, ImTextureID screen_img, ImVec2 size,
+                ImU32 bg_col, ImU32 overlay_col);
+bool SimuScreenMouseEvent(const ScreenDesc& desc, ScreenMouseEvent& event);
@@ -31,7 +31,7 @@
  void backlightEnable(uint8_t level) {}
  void backlightFullOn() {}
  void backlightDisable() {}
-  uint8_t isBacklightEnabled() {return false;}
+  bool isBacklightEnabled() { return false; }
 #elif defined(PCBX9E)
 void backlightInit()
 {
@@ -65,7 +65,7 @@ void backlightDisable()
  BACKLIGHT_TIMER->CCR2 = 0;
 }

-uint8_t isBacklightEnabled()
+bool isBacklightEnabled()
 {
  return (BACKLIGHT_TIMER->CCR1 != 0 || BACKLIGHT_TIMER->CCR2 != 0);
 }
@@ -103,7 +103,7 @@ void backlightDisable()
  BACKLIGHT_TIMER->CCR2 = 0;
 }

-uint8_t isBacklightEnabled()
+bool isBacklightEnabled()
 {
  return (BACKLIGHT_TIMER->CCR4 != 0 || BACKLIGHT_TIMER->CCR2 != 0);
 }
@@ -144,7 +144,7 @@ void backlightDisable()
  BACKLIGHT_COUNTER_REGISTER = 0;
 }

-uint8_t isBacklightEnabled()
+bool isBacklightEnabled()
 {
  return BACKLIGHT_COUNTER_REGISTER != 0;
 }
@@ -178,7 +178,7 @@ void backlightDisable()
  BACKLIGHT_TIMER->CCR1 = 0;
 }

-uint8_t isBacklightEnabled()
+bool isBacklightEnabled()
 {
  return BACKLIGHT_TIMER->CCR1 != 0;
 }
@@ -202,7 +202,7 @@ void pwrResetHandler();
 void backlightInit();
 void backlightDisable();
 void backlightFullOn();
-uint8_t isBacklightEnabled();
+bool isBacklightEnabled();

 #if defined(PCBX9E) || defined(PCBX9DP)
  void backlightEnable(uint8_t level, uint8_t color);
@@ -128,18 +128,6 @@ uint16_t simu_get_analog(uint8_t idx)
  return 0;
 }

-void fsLedRGB(uint8_t idx, uint32_t color)
-{
-}
-
-void fsLedOn(uint8_t idx)
-{
-}
-
-void fsLedOff(uint8_t idx)
-{
-}
-
 static char _stringResult[200];

 const char * nchar2string(const char * string, int size)
@@ -333,7 +333,7 @@ TCHAR* f_gets (TCHAR* buff, int len, FIL* fp);						/* Get a string from the fil
 #define f_eof(fp) ((int)((fp)->fptr == (fp)->obj.objsize))
 #define f_error(fp) ((fp)->err)
 #define f_tell(fp) ((fp)->fptr)
-#if defined(SIMU)
+#if defined(SIMU) && !defined(SIMU_DISKIO)
 UINT f_size(FIL* fil);
 #else
 #define f_size(fp) ((fp)->obj.objsize)