diff --git a/companion/src/CMakeLists.txt b/companion/src/CMakeLists.txt
index 03947e196..38aa68fed 100644
--- a/companion/src/CMakeLists.txt
+++ b/companion/src/CMakeLists.txt
@@ -33,8 +33,9 @@ IF ( SDL_FOUND )
     INCLUDE_DIRECTORIES( ${SDL_INCLUDE_DIR} )
     MESSAGE("SDL Include Path: " ${SDL_INCLUDE_DIR} )
     ADD_DEFINITIONS( -DJOYSTICKS )
+    ADD_DEFINITIONS( -DSIMU_AUDIO )
 ELSE()
-    MESSAGE( "SDL not found! Joysticks support will be disabled" )
+    MESSAGE( "SDL not found! Joysticks support will be disabled. Simulator audio will not work." )
 ENDIF()
 
 FIND_PACKAGE(Qt4 4.8.4 REQUIRED)
diff --git a/companion/src/firmwares/opentx/opentxSky9xsimulator.cpp b/companion/src/firmwares/opentx/opentxSky9xsimulator.cpp
index 53f8f2c78..e16ccad12 100644
--- a/companion/src/firmwares/opentx/opentxSky9xsimulator.cpp
+++ b/companion/src/firmwares/opentx/opentxSky9xsimulator.cpp
@@ -198,7 +198,7 @@ bool Open9xSky9xSimulator::timer10ms()
 #include "simulatorimport.h"
 }
 
-uint8_t * Open9xSky9xSimulator::getLcd()
+::uint8_t * Open9xSky9xSimulator::getLcd()
 {
 #define GETLCD_IMPORT
 #include "simulatorimport.h"
@@ -215,6 +215,7 @@ void Open9xSky9xSimulator::start(QByteArray & eeprom, bool tests)
   g_rotenc[0] = 0;
   memcpy(Open9xSky9x::eeprom, eeprom.data(), std::min<int>(sizeof(Open9xSky9x::eeprom), eeprom.size()));
   StartEepromThread(NULL);
+  StartAudioThread();
   StartMainThread(tests);
 }
 
@@ -222,12 +223,14 @@ void Open9xSky9xSimulator::start(const char * filename, bool tests)
 {
   g_rotenc[0] = 0;
   StartEepromThread(filename);
+  StartAudioThread();
   StartMainThread(tests);
 }
 
 void Open9xSky9xSimulator::stop()
 {
   StopMainThread();
+  StopAudioThread();
   StopEepromThread();
 }
 
@@ -249,27 +252,27 @@ void Open9xSky9xSimulator::setValues(TxInputs &inputs)
 void Open9xSky9xSimulator::setTrim(unsigned int idx, int value)
 {
   idx = Open9xSky9x::modn12x3[4*getStickMode() + idx];
-  uint8_t phase = getTrimFlightPhase(getFlightMode(), idx);
+  ::uint8_t phase = getTrimFlightPhase(getFlightMode(), idx);
   setTrimValue(phase, idx, value);
 }
 
 void Open9xSky9xSimulator::getTrims(Trims & trims)
 {
-  uint8_t phase = getFlightMode();
+  ::uint8_t phase = getFlightMode();
   trims.extended = hasExtendedTrims();
-  for (uint8_t idx=0; idx<4; idx++) {
+  for (::uint8_t idx=0; idx<4; idx++) {
     trims.values[idx] = getTrimValue(getTrimFlightPhase(phase, idx), idx);
   }
 
   for (int i=0; i<2; i++) {
-    uint8_t idx = Open9xSky9x::modn12x3[4*getStickMode() + i];
-    int16_t tmp = trims.values[i];
+    ::uint8_t idx = Open9xSky9x::modn12x3[4*getStickMode() + i];
+    ::int16_t tmp = trims.values[i];
     trims.values[i] = trims.values[idx];
     trims.values[idx] = tmp;
   }
 }
 
-void Open9xSky9xSimulator::wheelEvent(uint8_t steps)
+void Open9xSky9xSimulator::wheelEvent(::uint8_t steps)
 {
   g_rotenc[0] += steps*4;
 }
@@ -292,7 +295,7 @@ const char * Open9xSky9xSimulator::getError()
 #include "simulatorimport.h"
 }
 
-void Open9xSky9xSimulator::setTrainerInput(unsigned int inputNumber, int16_t value)
+void Open9xSky9xSimulator::setTrainerInput(unsigned int inputNumber, ::int16_t value)
 {
 #define SETTRAINER_IMPORT
 #include "simulatorimport.h"
diff --git a/companion/src/firmwares/opentx/opentxTaranisSimulator.cpp b/companion/src/firmwares/opentx/opentxTaranisSimulator.cpp
index 9f7065c19..3fd6fb343 100644
--- a/companion/src/firmwares/opentx/opentxTaranisSimulator.cpp
+++ b/companion/src/firmwares/opentx/opentxTaranisSimulator.cpp
@@ -145,10 +145,9 @@ inline int geteepromsize() {
 #include "radio/src/haptic.cpp"
 #include "radio/src/sbus.cpp"
 #include "radio/src/targets/taranis/haptic_driver.cpp"
-// TODO Because FatFS in not C++ there cannot be namespaces there and the functions are defined several times!
-#undef SDCARD
+// Because FatFS in not C++ there cannot be namespaces there and the functions are defined several times!
+#define SKIP_FATFS_DECLARATION
 #include "radio/src/targets/simu/simpgmspace.cpp"
-#define SDCARD
 #include "radio/src/translations.cpp"
 #include "radio/src/gui/Taranis/fonts.cpp"
 #include "radio/src/telemetry/telemetry.cpp"
@@ -245,7 +244,7 @@ bool OpentxTaranisSimulator::timer10ms()
 #include "simulatorimport.h"
 }
 
-uint8_t * OpentxTaranisSimulator::getLcd()
+::uint8_t * OpentxTaranisSimulator::getLcd()
 {
 #define GETLCD_IMPORT
 #include "simulatorimport.h"
@@ -261,18 +260,21 @@ void OpentxTaranisSimulator::start(QByteArray & eeprom, bool tests)
 {
   memcpy(Open9xX9D::eeprom, eeprom.data(), std::min<int>(sizeof(Open9xX9D::eeprom), eeprom.size()));
   StartEepromThread(NULL);
+  StartAudioThread();
   StartMainThread(tests);
 }
 
 void OpentxTaranisSimulator::start(const char * filename, bool tests)
 {
   StartEepromThread(filename);
+  StartAudioThread();
   StartMainThread(tests);
 }
 
 void OpentxTaranisSimulator::stop()
 {
   StopMainThread();
+  StopAudioThread();
   StopEepromThread();
 }
 
@@ -292,27 +294,27 @@ void OpentxTaranisSimulator::setValues(TxInputs &inputs)
 void OpentxTaranisSimulator::setTrim(unsigned int idx, int value)
 {
   idx = Open9xX9D::modn12x3[4*getStickMode() + idx];
-  uint8_t phase = getTrimFlightPhase(getFlightMode(), idx);
+  ::uint8_t phase = getTrimFlightPhase(getFlightMode(), idx);
   setTrimValue(phase, idx, value);
 }
 
 void OpentxTaranisSimulator::getTrims(Trims & trims)
 {
-  uint8_t phase = getFlightMode();
+  ::uint8_t phase = getFlightMode();
   trims.extended = hasExtendedTrims();
-  for (uint8_t idx=0; idx<4; idx++) {
+  for (::uint8_t idx=0; idx<4; idx++) {
     trims.values[idx] = getTrimValue(getTrimFlightPhase(phase, idx), idx);
   }
 
   for (int i=0; i<2; i++) {
-    uint8_t idx = Open9xX9D::modn12x3[4*getStickMode() + i];
-    int16_t tmp = trims.values[i];
+    ::uint8_t idx = Open9xX9D::modn12x3[4*getStickMode() + i];
+    ::int16_t tmp = trims.values[i];
     trims.values[i] = trims.values[idx];
     trims.values[idx] = tmp;
   }
 }
 
-void OpentxTaranisSimulator::wheelEvent(uint8_t steps)
+void OpentxTaranisSimulator::wheelEvent(::uint8_t steps)
 {
   // g_rotenc[0] += steps*4;
 }
@@ -335,12 +337,12 @@ const char * OpentxTaranisSimulator::getError()
 #include "simulatorimport.h"
 }
 
-void OpentxTaranisSimulator::sendTelemetry(uint8_t * data, unsigned int len) 
+void OpentxTaranisSimulator::sendTelemetry(::uint8_t * data, unsigned int len) 
 {
   processSportPacket(data);
 }
 
-void OpentxTaranisSimulator::setTrainerInput(unsigned int inputNumber, int16_t value)
+void OpentxTaranisSimulator::setTrainerInput(unsigned int inputNumber, ::int16_t value)
 {
 #define SETTRAINER_IMPORT
 #include "simulatorimport.h"
diff --git a/companion/src/simulation/simulatorimport.h b/companion/src/simulation/simulatorimport.h
index 48d3b5e0a..2791ad7c0 100644
--- a/companion/src/simulation/simulatorimport.h
+++ b/companion/src/simulation/simulatorimport.h
@@ -106,6 +106,6 @@ return main_thread_error;
 #ifdef SETTRAINER_IMPORT
 #undef SETTRAINER_IMPORT
   ppmInValid = 100;
-  g_ppmIns[inputNumber] = LIMIT<int16_t>(-512, value, 512);
+  g_ppmIns[inputNumber] = LIMIT< ::int16_t>(-512, value, 512);
 #endif
 
diff --git a/radio/src/Makefile b/radio/src/Makefile
index a11ce208a..41b158a65 100644
--- a/radio/src/Makefile
+++ b/radio/src/Makefile
@@ -348,6 +348,10 @@ TARANIS_INTERNAL_PPM = NO
 # Values = NO, YES
 SIMU_DISKIO = NO
 
+# Enable audio in simulator
+# Values = NO, YES
+SIMU_AUDIO = NO
+
 #------- END BUILD OPTIONS ---------------------------
 
 # Define programs and commands.
@@ -1567,13 +1571,20 @@ FOXLIB=-L/usr/local/lib \
        -lFOX-1.6 \
        -Wl,-rpath,$(FOXPATH)/src/.libs
 
+SIMUDEFS = -DSIMU -DLUA_USE_APICHECK
+ifeq ($(SIMU_AUDIO), YES)
+  AUDIOLIB = -L/usr/lib/x86_64-linux-gnu/ -lSDLmain -lSDL
+  AUDIOINC = -I/usr/include/SDL
+  SIMUDEFS += -DSIMU_AUDIO
+endif
+
 ifeq ($(SIMU_DISKIO), YES)
-  CPPDEFS += -DSIMU_DISKIO
   CPPSRC += FatFs/ff.c FatFs/option/ccsbcs.c
+  SIMUDEFS += -DSIMU_DISKIO
 endif
 
 simu: $(LUADEP) stamp_header allsimusrc.cpp Makefile simu.cpp targets/simu/simpgmspace.cpp *.h tra lbm eeprom.bin
-	g++ $(CPPFLAGS) $(INCFLAGS) simu.cpp allsimusrc.cpp $(LUASRC) targets/simu/simpgmspace.cpp -MD -DSIMU -DLUA_USE_APICHECK -O0 -o simu $(FOXINC) $(FOXLIB) -pthread -fexceptions
+	g++ $(CPPFLAGS) $(INCFLAGS) simu.cpp allsimusrc.cpp $(LUASRC) targets/simu/simpgmspace.cpp -MD $(SIMUDEFS) -O0 -o simu $(FOXINC) $(FOXLIB) $(AUDIOINC) $(AUDIOLIB) -pthread -fexceptions
 
 eeprom.bin:
 	dd if=/dev/zero of=$@ bs=1 count=2048
diff --git a/radio/src/audio_arm.cpp b/radio/src/audio_arm.cpp
index 22789a2f5..52e97764b 100644
--- a/radio/src/audio_arm.cpp
+++ b/radio/src/audio_arm.cpp
@@ -362,14 +362,17 @@ void referenceModelAudioFiles()
 
       // Eliminates directories / non wav files
       if (len < 5 || strcasecmp(fn+len-4, SOUNDS_EXT) || (fno.fattrib & AM_DIR)) continue;
+      TRACE("referenceModelAudioFiles(): using file: %s", fn);
 
       // Phases Audio Files <phasename>-[on|off].wav
       for (int i=0; i<MAX_FLIGHT_MODES && !found; i++) {
         for (int event=0; event<2; event++) {
           getPhaseAudioFile(path, i, event);
+          // TRACE("referenceModelAudioFiles(): searching for %s in %s", filename, fn);
           if (!strcasecmp(filename, fn)) {
             sdAvailablePhaseAudioFiles |= MASK_PHASE_AUDIO_FILE(i, event);
             found = true;
+            TRACE("\tfound: %s", filename);
             break;
           }
         }
@@ -378,9 +381,11 @@ void referenceModelAudioFiles()
       // Switches Audio Files <switchname>-[up|mid|down].wav
       for (int i=0; i<SWSRC_LAST_SWITCH+NUM_XPOTS*XPOTS_MULTIPOS_COUNT && !found; i++) {
         getSwitchAudioFile(path, i);
+        // TRACE("referenceModelAudioFiles(): searching for %s in %s", filename, fn);
         if (!strcasecmp(filename, fn)) {
           sdAvailableSwitchAudioFiles |= MASK_SWITCH_AUDIO_FILE(i);
           found = true;
+          TRACE("\tfound: %s", filename);
         }
       }
 
@@ -388,9 +393,11 @@ void referenceModelAudioFiles()
       for (int i=0; i<NUM_LOGICAL_SWITCH && !found; i++) {
         for (int event=0; event<2; event++) {
           getLogicalSwitchAudioFile(path, i, event);
+          // TRACE("referenceModelAudioFiles(): searching for %s in %s", filename, fn);
           if (!strcasecmp(filename, fn)) {
             sdAvailableLogicalSwitchAudioFiles |= MASK_LOGICAL_SWITCH_AUDIO_FILE(i, event);
             found = true;
+            TRACE("\tfound: %s", filename);
             break;
           }
         }
@@ -499,10 +506,14 @@ void audioTask(void* pdata)
 
 void mixSample(uint16_t * result, int sample, unsigned int fade)
 {
+#if defined(SIMU_AUDIO)
+  *result = limit(0, *result + ((sample >> fade) ), 0xFFFF);
+#else
   *result = limit(0, *result + ((sample >> fade) >> 4), 4095);
+#endif
 }
 
-#if defined(SDCARD) && !defined(SIMU)
+#if defined(SDCARD)
 
 #define RIFF_CHUNK_SIZE 12
 uint8_t wavBuffer[AUDIO_BUFFER_SIZE*2];
@@ -695,7 +706,11 @@ void AudioQueue::wakeup()
 
     // write silence in the buffer
     for (uint32_t i=0; i<AUDIO_BUFFER_SIZE; i++) {
+#if defined(SIMU_AUDIO)
+      buffer->data[i] = 0x8000; /* silence */
+#else
       buffer->data[i] = 0x8000 >> 4; /* silence */
+#endif
     }
 
     // mix the priority context (only tones)
@@ -751,6 +766,7 @@ void AudioQueue::wakeup()
     // push the buffer if needed
     if (size > 0) {
       __disable_irq();
+      // TRACE("pushing buffer %d\n", bufferWIdx);
       bufferWIdx = nextBufferIdx(bufferWIdx);
       buffer->size = size;
       buffer->state = dacQueue(buffer) ? AUDIO_BUFFER_PLAYING : AUDIO_BUFFER_FILLED;
@@ -793,6 +809,10 @@ bool AudioQueue::isPlaying(uint8_t id)
 
 void AudioQueue::playTone(uint16_t freq, uint16_t len, uint16_t pause, uint8_t flags, int8_t freqIncr)
 {
+#if defined(SIMU) && !defined(SIMU_AUDIO)
+  return;
+#endif
+
   CoEnterMutexSection(audioMutex);
 
   if (freq && freq < BEEP_MIN_FREQ) {
@@ -849,9 +869,13 @@ void AudioQueue::playFile(const char *filename, uint8_t flags, uint8_t id)
   TRACE("playFile(\"%s\", flags=%x, id=%d)", filename, flags, id);
   if (strlen(filename) > AUDIO_FILENAME_MAXLEN) {
     TRACE("file name too long! maximum length is %d characters", AUDIO_FILENAME_MAXLEN);
+    return;
   }
-  fflush(stdout);
-#else
+  #if !defined(SIMU_AUDIO)
+  return;
+  #endif
+#endif
+
 
   if (!sdMounted())
     return;
@@ -887,7 +911,6 @@ void AudioQueue::playFile(const char *filename, uint8_t flags, uint8_t id)
   }
 
   CoLeaveMutexSection(audioMutex);
-#endif
 }
 
 void AudioQueue::stopPlay(uint8_t id)
@@ -896,6 +919,10 @@ void AudioQueue::stopPlay(uint8_t id)
   TRACE("stopPlay(id=%d)", id);
 #endif
 
+#if defined(SIMU) && !defined(SIMU_AUDIO)
+  return;
+#endif
+
   // For the moment it's only needed to stop the background music
   if (backgroundContext.fragment.id == id) {
     backgroundContext.fragment.type = FRAGMENT_EMPTY;
diff --git a/radio/src/audio_arm.h b/radio/src/audio_arm.h
index ddacdde09..b3a5fb5ba 100644
--- a/radio/src/audio_arm.h
+++ b/radio/src/audio_arm.h
@@ -46,7 +46,11 @@
 #define AUDIO_SAMPLE_RATE     (32000)
 #define AUDIO_BUFFER_DURATION (10)
 #define AUDIO_BUFFER_SIZE     (AUDIO_SAMPLE_RATE*AUDIO_BUFFER_DURATION/1000)
-#define AUDIO_BUFFER_COUNT    (3)
+#if defined(SIMU_AUDIO)
+  #define AUDIO_BUFFER_COUNT  (10)      // simulator needs more buffers for smooth audio
+#else
+  #define AUDIO_BUFFER_COUNT  (3)
+#endif
 
 #define BEEP_MIN_FREQ         (150)
 #define BEEP_DEFAULT_FREQ     (2250)
@@ -155,6 +159,9 @@ bool dacQueue(AudioBuffer *buffer);
 class AudioQueue {
 
   friend void audioTask(void* pdata);
+#if defined(SIMU_AUDIO)
+  friend void *audio_thread(void *);
+#endif
 
   public:
 
@@ -196,7 +203,7 @@ class AudioQueue {
       }
 
       uint8_t idx = bufferRIdx;
-      while (idx != bufferWIdx) {
+      do {
         AudioBuffer * buffer = &buffers[idx];
         if (buffer->state == AUDIO_BUFFER_FILLED) {
           buffer->state = AUDIO_BUFFER_PLAYING;
@@ -204,11 +211,23 @@ class AudioQueue {
           return buffer;
         }
         idx = nextBufferIdx(idx);
-      }
+      } while (idx != bufferWIdx);   //this fixes a bug if all buffers are filled
 
       return NULL;
     }
 
+    bool filledAtleast(int noBuffers) {
+      int count = 0;
+      for(int n= 0; n<AUDIO_BUFFER_COUNT; ++n) {
+        if (buffers[n].state == AUDIO_BUFFER_FILLED) {
+          if (++count >= noBuffers) {
+            return true;
+          }
+        }
+      }
+      return false;
+    }
+
   protected:
 
     void wakeup();
diff --git a/radio/src/simu.cpp b/radio/src/simu.cpp
index aba58a0d6..94679fbe3 100644
--- a/radio/src/simu.cpp
+++ b/radio/src/simu.cpp
@@ -134,6 +134,7 @@ Open9xSim::Open9xSim(FXApp* a):
 Open9xSim::~Open9xSim()
 {
   StopMainThread();
+  StopAudioThread();
   StopEepromThread();
   
   delete bmp;
@@ -430,6 +431,7 @@ int main(int argc,char **argv)
   printf("Model size = %d\n", (int)sizeof(g_model));
 
   StartEepromThread(argc >= 2 ? argv[1] : "eeprom.bin");
+  StartAudioThread();
   StartMainThread();
 
 #if defined(PCBTARANIS)
diff --git a/radio/src/targets/simu/simpgmspace.cpp b/radio/src/targets/simu/simpgmspace.cpp
index 2150bfc93..cfa5fbf74 100644
--- a/radio/src/targets/simu/simpgmspace.cpp
+++ b/radio/src/targets/simu/simpgmspace.cpp
@@ -51,6 +51,10 @@
   FILE * diskImage = 0;
 #endif
 
+#if defined(SIMU_AUDIO) && defined(CPUARM)
+  #include <SDL.h>
+#endif
+
 volatile uint8_t pina=0xff, pinb=0xff, pinc=0xff, pind, pine=0xff, pinf=0xff, ping=0xff, pinh=0xff, pinj=0xff, pinl=0;
 uint8_t portb, portc, porth=0, dummyport;
 uint16_t dummyport16;
@@ -89,7 +93,7 @@ Adc Adc0;
   #define EESIZE_SIMU EESIZE
 #endif
 
-#if defined(SDCARD)
+#if defined(SDCARD) && !defined(SKIP_FATFS_DECLARATION)
 char simuSdDirectory[1024] = "";
 #endif
 
@@ -402,7 +406,7 @@ void StartMainThread(bool tests)
   pthread_mutex_init(&audioMutex, NULL);
 #endif
 
-  g_tmr10ms = 0;
+  g_tmr10ms = 1;      // must be non-zero otherwise some SF functions (that use this timer as a marker when it was last executed) will be executed twice on startup
 #if defined(RTCLOCK)
   g_rtcTime = time(0);
 #endif
@@ -417,7 +421,130 @@ void StopMainThread()
   pthread_join(main_thread_pid, NULL);
 }
 
+#if defined(CPUARM)
+int Volume = volumeScale[VOLUME_LEVEL_DEF];
+bool dacQueue(AudioBuffer *buffer)
+{
+  return false;
+}
+
+void setVolume(uint8_t volume)
+{
+  Volume = volumeScale[min<uint8_t>(volume, VOLUME_LEVEL_MAX)];
+}
+#endif
+
+#if defined(SIMU_AUDIO) && defined(CPUARM)
+
+int leftover_len = 0;
+uint16_t leftover_data[AUDIO_BUFFER_SIZE];
+
+void copyBuffer(uint8_t * dest, uint16_t * buff, unsigned int samples) 
+{
+  for(unsigned int i=0; i<samples; i++) {
+    int sample = ((int32_t)(uint32_t)(buff[i]) - 0x8000);  // conversion from uint16_t 
+    *((uint16_t*)dest) = (int16_t)((sample * Volume)/127);
+    dest += 2;
+  }
+}
+
+void fill_audio(void *udata, Uint8 *stream, int len)
+{
+  SDL_memset(stream, 0, len);
+
+  if (leftover_len) {
+    copyBuffer(stream, leftover_data, leftover_len);
+    len -= leftover_len*2;
+    stream += leftover_len*2;
+    leftover_len = 0;
+    // putchar('l');
+  }
+
+  if (audioQueue.filledAtleast(len/(AUDIO_BUFFER_SIZE*2)+1) ) {
+    while(true) {
+      AudioBuffer *nextBuffer = audioQueue.getNextFilledBuffer();
+      if (nextBuffer) {
+        if (len >= nextBuffer->size*2) {
+          copyBuffer(stream, nextBuffer->data, nextBuffer->size);
+          stream += nextBuffer->size*2;
+          len -= nextBuffer->size*2;
+          // putchar('+');
+        }
+        else {
+          //partial
+          copyBuffer(stream, nextBuffer->data, len/2);
+          leftover_len = (nextBuffer->size-len/2);
+          memcpy(leftover_data, &nextBuffer->data[len/2], leftover_len*2);
+          len = 0;
+          // putchar('p');
+          break;
+        }
+      }
+      else {
+        break;
+      }
+    }
+  }
+
+  //fill the rest of buffer with silence
+  if (len > 0) {
+    SDL_memset(stream, 0x8000, len);  // make sure this is silence.
+    // putchar('.');
+  }
+}
+
+bool audio_thread_running = false;
+
+void *audio_thread(void *)
+{
+  SDL_AudioSpec wanted, have;
+
+  /* Set the audio format */
+  wanted.freq = AUDIO_SAMPLE_RATE;
+  wanted.format = AUDIO_S16SYS;
+  wanted.channels = 1;    /* 1 = mono, 2 = stereo */
+  wanted.samples = AUDIO_BUFFER_SIZE*2;  /* Good low-latency value for callback */
+  wanted.callback = fill_audio;
+  wanted.userdata = NULL;
+
+  /* Open the audio device, forcing the desired format */
+  if ( SDL_OpenAudio(&wanted, &have) < 0 ) {
+    fprintf(stderr, "Couldn't open audio: %s\n", SDL_GetError());
+    return 0;
+  }
+  SDL_PauseAudio(0);
+
+  while (audio_thread_running) {
+    audioQueue.wakeup();
+    sleep(1);
+  }
+  SDL_CloseAudio();
+  return 0;
+}
+
+pthread_t audio_thread_pid;
+
+void StartAudioThread()
+{ 
+  pthread_attr_t attr;
+  pthread_attr_init(&attr);
+  struct sched_param sp;
+  sp.sched_priority = SCHED_RR;
+  pthread_attr_setschedparam(&attr, &sp);
+  pthread_create(&audio_thread_pid, &attr, &audio_thread, NULL);
+  audio_thread_running = true;
+  return;
+}
+
+void StopAudioThread()
+{
+  audio_thread_running = false;
+  pthread_join(audio_thread_pid, NULL);
+}
+#endif // #if defined(CPUARM)
+
 pthread_t eeprom_thread_pid;
+
 void StartEepromThread(const char *filename)
 {
   eepromFile = filename;
@@ -510,16 +637,23 @@ static void EeFsDump(){
 }
 #endif
 
-#if defined(SDCARD) && !defined(SIMU_DISKIO)
+#if defined(SDCARD) && !defined(SKIP_FATFS_DECLARATION) && !defined(SIMU_DISKIO)
 namespace simu {
 #include <dirent.h>
+#if !defined WIN32
+  #include <libgen.h>
+#endif
 }
 #include "FatFs/ff.h"
 
 #if defined WIN32 || !defined __GNUC__
 #include <direct.h>
+#include <stdlib.h>
 #endif
 
+#include <map>
+#include <string>
+
 #if defined(CPUARM)
 FATFS g_FATFS_Obj;
 #endif
@@ -535,11 +669,89 @@ char *convertSimuPath(const char *path)
   return result;
 }
 
+typedef std::map<std::string, std::string> filemap_t;
+
+filemap_t fileMap;
+
+char *findTrueFileName(const char *path)
+{
+  TRACE("findTrueFileName(%s)", path);
+  static char result[1024];
+  filemap_t::iterator i = fileMap.find(path);
+  if (i != fileMap.end()) {
+    strcpy(result, i->second.c_str());
+    TRACE("\tfound in map: %s", result);
+    return result;
+  }
+  else {
+    //find file
+    //add to map
+#if defined WIN32 || !defined __GNUC__
+    char drive[_MAX_DRIVE];
+    char dir[_MAX_DIR];
+    char fname[_MAX_FNAME];
+    char ext[_MAX_EXT];
+    _splitpath(path, drive, dir, fname, ext);
+    std::string fileName = std::string(fname) + "." + std::string(ext);
+    std::string dirName = std::string(drive) + std::string(dir);
+    if (dir) {
+      // TRACE("\tsearching for: %s", fileName.c_str());
+      WIN32_FIND_DATA ffd;
+      HANDLE hFind = FindFirstFile(dirName.c_str(), &ffd);
+      if (INVALID_HANDLE_VALUE != hFind) {
+        do {
+          if (ffd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY == 0) {
+            // TRACE("comparing with: %s", ffd.cFileName);
+            if (!strcasecmp(fileName.c_str(), ffd.cFileName)) {
+              strcpy(result, dirName.c_str());
+              strcat(result, "/");
+              strcat(result, ffd.cFileName);
+              TRACE("\tfound: %s", ffd.cFileName);
+              fileMap.insert(filemap_t:: value_type(path, result));
+              return result;  
+            }
+          }
+        }
+        while (FindNextFile(hFind, &ffd) != 0);
+      }
+    }
+#else
+    strcpy(result, path);
+    std::string fileName = simu::basename(result);
+    strcpy(result, path);
+    std::string dirName = simu::dirname(result);
+    simu::DIR * dir = simu::opendir(dirName.c_str());
+    if (dir) {
+      // TRACE("\tsearching for: %s", fileName.c_str());
+      for (;;) {
+        struct simu::dirent * res = simu::readdir(dir);
+        if (res == 0) break;
+        if ((res->d_type == simu::DT_REG) || (res->d_type == simu::DT_LNK)) {
+          // TRACE("comparing with: %s", res->d_name);
+          if (!strcasecmp(fileName.c_str(), res->d_name)) {
+            strcpy(result, dirName.c_str());
+            strcat(result, "/");
+            strcat(result, res->d_name);
+            TRACE("\tfound: %s", res->d_name);
+            fileMap.insert(filemap_t:: value_type(path, result));
+            return result;  
+          }
+        }
+      }
+    }
+#endif
+  }
+  TRACE("\tnot found");
+  strcpy(result, path);
+  return result;
+}
+
 FRESULT f_stat (const TCHAR * name, FILINFO *)
 {
   char *path = convertSimuPath(name);
+  char * realPath = findTrueFileName(path);
   struct stat tmp;
-  if (stat(path, &tmp)) {
+  if (stat(realPath, &tmp)) {
     TRACE("f_stat(%s) = error %d (%s)", path, errno, strerror(errno));
     return FR_INVALID_NAME;
   }
@@ -557,17 +769,19 @@ FRESULT f_mount (FATFS* ,const TCHAR*, BYTE opt)
 FRESULT f_open (FIL * fil, const TCHAR *name, BYTE flag)
 {
   char *path = convertSimuPath(name);
+  char * realPath = findTrueFileName(path);
   if (!(flag & FA_WRITE)) {
     struct stat tmp;
-    if (stat(path, &tmp)) {
+    if (stat(realPath, &tmp)) {
       TRACE("f_open(%s) = INVALID_NAME", path);
       return FR_INVALID_NAME;
     }
     fil->fsize = tmp.st_size;
   }
-  fil->fs = (FATFS*)fopen(path, (flag & FA_WRITE) ? "wb+" : "rb+");
-  if ( fil->fs ) {
-    TRACE("f_open(%s) = OK", path);
+  fil->fs = (FATFS*)fopen(realPath, (flag & FA_WRITE) ? "wb+" : "rb+");
+  fil->fptr = 0;
+  if (fil->fs) {
+    TRACE("f_open(%s) = %p", path, (FILE*)fil->fs);
     return FR_OK;
   }
   TRACE("f_open(%s) = error %d (%s)", path, errno, strerror(errno));
@@ -578,6 +792,7 @@ FRESULT f_read (FIL* fil, void* data, UINT size, UINT* read)
 {
   if (fil && fil->fs) {
     *read = fread(data, 1, size, (FILE*)fil->fs);
+    fil->fptr += *read;
     // TRACE("fread(%p) %u, %u", fil->fs, size, *read);
   }
   return FR_OK;
@@ -587,6 +802,7 @@ FRESULT f_write (FIL* fil, const void* data, UINT size, UINT* written)
 {
   if (fil && fil->fs) {
     *written = fwrite(data, 1, size, (FILE*)fil->fs);
+    fil->fptr += size;
     // TRACE("fwrite(%p) %u, %u", fil->fs, size, *written);
   }
   return FR_OK;
@@ -595,12 +811,14 @@ FRESULT f_write (FIL* fil, const void* data, UINT size, UINT* written)
 FRESULT f_lseek (FIL* fil, DWORD offset)
 {
   if (fil && fil->fs) fseek((FILE*)fil->fs, offset, SEEK_SET);
+  fil->fptr = offset;
   return FR_OK;
 }
 
 FRESULT f_close (FIL * fil)
 {
   if (fil && fil->fs) {
+    TRACE("f_close(%p)", (FILE*)fil->fs);
     fclose((FILE*)fil->fs);
     fil->fs = NULL;
   }
@@ -724,7 +942,7 @@ int32_t Card_state = SD_ST_MOUNTED;
 uint32_t Card_CSD[4]; // TODO elsewhere
 #endif
 
-#endif  // #if defined(SDCARD) && !defined(SIMU_DISKIO)
+#endif  // #if defined(SDCARD) && !defined(SKIP_FATFS_DECLARATION) && !defined(SIMU_DISKIO)
 
 
 #if defined(SIMU_DISKIO)
diff --git a/radio/src/targets/simu/simpgmspace.h b/radio/src/targets/simu/simpgmspace.h
index 84398bf21..3a984072c 100644
--- a/radio/src/targets/simu/simpgmspace.h
+++ b/radio/src/targets/simu/simpgmspace.h
@@ -363,6 +363,13 @@ void StartMainThread(bool tests=true);
 void StopMainThread();
 void StartEepromThread(const char *filename="eeprom.bin");
 void StopEepromThread();
+#if defined(SIMU_AUDIO) && defined(CPUARM)
+  void StartAudioThread(void);
+  void StopAudioThread(void);
+#else
+  #define StartAudioThread()
+  #define StopAudioThread()
+#endif
 
 extern const char *eepromFile;
 #if defined(PCBTARANIS) || defined(PCBACT)
diff --git a/radio/src/targets/sky9x/audio_driver.cpp b/radio/src/targets/sky9x/audio_driver.cpp
index 4cfe0b25b..0a9c096a6 100644
--- a/radio/src/targets/sky9x/audio_driver.cpp
+++ b/radio/src/targets/sky9x/audio_driver.cpp
@@ -36,6 +36,14 @@
 
 #include "../../opentx.h"
 
+const int8_t volumeScale[VOLUME_LEVEL_MAX+1] =
+{
+    0,  2,  4,   6,   8,  10,  13,  17,  22,  27,  33,  40,
+    64, 82, 96, 105, 112, 117, 120, 122, 124, 125, 126, 127
+} ;
+
+#if !defined(SIMU)
+
 void setSampleRate(uint32_t frequency)
 {
   register Tc *ptc ;
@@ -154,12 +162,6 @@ void audioEnd()
   PMC->PMC_PCER0 &= ~0x40000000L ;		// Disable peripheral clock to DAC
 }
 
-static const int8_t volumeScale[VOLUME_LEVEL_MAX+1] =
-{
-    0,  2,  4,   6,   8,  10,  13,  17,  22,  27,  33,  40,
-    64, 82, 96, 105, 112, 117, 120, 122, 124, 125, 126, 127
-} ;
-
 void setVolume(uint8_t volume)
 {
   volumeRequired = volumeScale[min<uint8_t>(volume, VOLUME_LEVEL_MAX)];
@@ -169,4 +171,5 @@ void setVolume(uint8_t volume)
 }
 
 
+#endif // #if !defined(SIMU)
 
diff --git a/radio/src/targets/sky9x/audio_driver.h b/radio/src/targets/sky9x/audio_driver.h
index 72e67fa21..f37f6eb58 100644
--- a/radio/src/targets/sky9x/audio_driver.h
+++ b/radio/src/targets/sky9x/audio_driver.h
@@ -55,6 +55,8 @@ inline void dacStop()
 
 #define VOLUME_LEVEL_MAX  23
 #define VOLUME_LEVEL_DEF  12
+extern const int8_t volumeScale[];
+
 void setVolume(uint8_t volume);
 
 #endif
diff --git a/radio/src/targets/taranis/audio_driver.cpp b/radio/src/targets/taranis/audio_driver.cpp
index e34f20c09..01e7f38a0 100644
--- a/radio/src/targets/taranis/audio_driver.cpp
+++ b/radio/src/targets/taranis/audio_driver.cpp
@@ -36,6 +36,13 @@
 
 #include "../../opentx.h"
 
+const int8_t volumeScale[VOLUME_LEVEL_MAX+1] =
+{
+    0,  1,  2,  3,  5,  9,  13,  17,  22,  27,  33,  40,
+    64, 82, 96, 105, 112, 117, 120, 122, 124, 125, 126, 127
+};
+
+#if !defined(SIMU)
 bool dacIdle = true;
 
 void setSampleRate(uint32_t frequency)
@@ -139,7 +146,6 @@ void audioEnd()
   NVIC_DisableIRQ(DMA1_Stream5_IRQn) ;
 }
 
-#if !defined(SIMU)
 extern "C" void TIM6_DAC_IRQHandler()
 {
   DAC->CR &= ~DAC_CR_DMAEN1 ;     // Stop DMA requests
@@ -167,7 +173,7 @@ extern "C" void DMA1_Stream5_IRQHandler()
     dacIdle = true;
   }
 }
-#endif
+#endif  // #if !defined(SIMU)
 
 #if 0
 static void Audio_GPIO_Init()
diff --git a/radio/src/targets/taranis/audio_driver.h b/radio/src/targets/taranis/audio_driver.h
index ea277a8ed..7d52c5203 100644
--- a/radio/src/targets/taranis/audio_driver.h
+++ b/radio/src/targets/taranis/audio_driver.h
@@ -46,16 +46,12 @@ extern void setSampleRate(uint32_t frequency);
 
 #define VOLUME_LEVEL_MAX  23
 #define VOLUME_LEVEL_DEF  12
-static const int8_t volumeScale[VOLUME_LEVEL_MAX+1] =
-{
-    0,  1,  2,  3,  5,  9,  13,  17,  22,  27,  33,  40,
-    64, 82, 96, 105, 112, 117, 120, 122, 124, 125, 126, 127
-} ;
+extern const int8_t volumeScale[];
 
 #if !defined(SIMU)
 #define setVolume(v) I2C_set_volume(volumeScale[min<uint8_t>(v, VOLUME_LEVEL_MAX)])
 #else
-#define setVolume(v)
+void setVolume(uint8_t volume);
 #endif
 
 #endif