diff --git a/radio/src/CMakeLists.txt b/radio/src/CMakeLists.txt
index a60d997ae..cba0c915d 100644
--- a/radio/src/CMakeLists.txt
+++ b/radio/src/CMakeLists.txt
@@ -474,6 +474,7 @@ set(SRC
   timers.cpp
   trainer.cpp
   model_init.cpp
+  serial.cpp
   )
 
 if(GUI)
diff --git a/radio/src/cli.cpp b/radio/src/cli.cpp
index b08cc51ef..3be2d23c4 100644
--- a/radio/src/cli.cpp
+++ b/radio/src/cli.cpp
@@ -37,6 +37,8 @@
 // CLI receive buffer size
 #define CLI_RX_BUFFER_SIZE 256
 
+#define CLI_PRINT_BUFFER_SIZE 128
+
 RTOS_TASK_HANDLE cliTaskId;
 RTOS_DEFINE_STACK(cliStack, CLI_STACK_SIZE);
 
@@ -49,6 +51,50 @@ static StreamBufferHandle_t cliRxBuffer;
 // CLI receive call back
 void (*cliReceiveCallBack)(uint8_t* buf, uint32_t len) = nullptr;
 
+// CLI send call back
+static void (*cliSendCb)(void*, uint8_t) = nullptr;
+static void* cliSendCtx = nullptr;
+
+void cliSetSendCb(void* ctx, void (*cb)(void*, uint8_t))
+{
+  cliSendCb = nullptr;
+  cliSendCtx = ctx;
+  cliSendCb = cb;
+}
+
+static void cliSerialPrintf(const char * format, ...)
+{
+  va_list arglist;
+  char tmp[CLI_PRINT_BUFFER_SIZE];
+
+  // no need to do anything if we don't have an output
+  if (!cliSendCb) return;
+  
+  va_start(arglist, format);
+  vsnprintf(tmp, CLI_PRINT_BUFFER_SIZE-1, format, arglist);
+  tmp[CLI_PRINT_BUFFER_SIZE-1] = '\0';
+  va_end(arglist);
+
+  const char *t = tmp;
+  while (*t && cliSendCb) {
+    cliSendCb(cliSendCtx, *t++);
+  }
+}
+
+#define cliSerialPrint(...) \
+  do { cliSerialPrintf(__VA_ARGS__); cliSerialCrlf(); } while(0)
+
+static void cliSerialPutc(uint8_t c)
+{
+  if (cliSendCb) cliSendCb(cliSendCtx, c);
+}
+
+static void cliSerialCrlf()
+{
+  cliSerialPutc('\r');
+  cliSerialPutc('\n');
+}
+
 uint8_t cliTracesEnabled = true;
 char cliLastLine[CLI_COMMAND_MAX_LEN+1];
 
@@ -73,8 +119,8 @@ struct MemArea
 
 void cliPrompt()
 {
-  serialPutc('>');
-  serialPutc(' ');
+  cliSerialPutc('>');
+  cliSerialPutc(' ');
 }
 
 int toLongLongInt(const char ** argv, int index, long long int * val)
@@ -94,7 +140,7 @@ int toLongLongInt(const char ** argv, int index, long long int * val)
     if (*endptr == '\0')
       return 1;
     else {
-      serialPrint("%s: Invalid argument \"%s\"", argv[0], argv[index]);
+      cliSerialPrint("%s: Invalid argument \"%s\"", argv[0], argv[index]);
       return -1;
     }
   }
@@ -134,12 +180,12 @@ int cliLs(const char ** argv)
     for (;;) {
       res = f_readdir(&dir, &fno);                   /* Read a directory item */
       if (res != FR_OK || fno.fname[0] == 0) break;  /* Break on error or end of dir */
-      serialPrint(fno.fname);
+      cliSerialPrint(fno.fname);
     }
     f_closedir(&dir);
   }
   else {
-    serialPrint("%s: Invalid directory \"%s\"", argv[0], argv[1]);
+    cliSerialPrint("%s: Invalid directory \"%s\"", argv[0], argv[1]);
   }
   return 0;
 }
@@ -150,20 +196,20 @@ int cliRead(const char ** argv)
   uint32_t bytesRead = 0;
   int bufferSize;
   if (toInt(argv, 2, &bufferSize) == 0 || bufferSize < 0 ) {
-    serialPrint("%s: Invalid buffer size \"%s\"", argv[0], argv[2]);
+    cliSerialPrint("%s: Invalid buffer size \"%s\"", argv[0], argv[2]);
     return 0;
   }
 
   uint8_t * buffer = (uint8_t*) malloc(bufferSize);
   if (!buffer) {
-    serialPrint("Not enough memory");
+    cliSerialPrint("Not enough memory");
     return 0;
   }
 
   FRESULT result = f_open(&file, argv[1], FA_OPEN_EXISTING | FA_READ);
   if (result != FR_OK) {
     free(buffer);
-    serialPrint("%s: File not found \"%s\"", argv[0], argv[1]);
+    cliSerialPrint("%s: File not found \"%s\"", argv[0], argv[1]);
     return 0;
   }
 
@@ -184,7 +230,7 @@ int cliRead(const char ** argv)
   uint32_t elapsedTime = (get_tmr10ms() - start) * 10;
   if (elapsedTime == 0) elapsedTime = 1;
   uint32_t speed = bytesRead / elapsedTime;
-  serialPrint("Read %d bytes in %d ms, speed %d kB/s", bytesRead, elapsedTime, speed);
+  cliSerialPrint("Read %d bytes in %d ms, speed %d kB/s", bytesRead, elapsedTime, speed);
   free(buffer);
   return 0;
 }
@@ -195,22 +241,22 @@ int cliReadSD(const char ** argv)
   int numberOfSectors;
   int bufferSectors;
   if (toInt(argv, 1, &startSector) == 0 || startSector < 0 ) {
-    serialPrint("%s: Invalid start sector \"%s\"", argv[0], argv[1]);
+    cliSerialPrint("%s: Invalid start sector \"%s\"", argv[0], argv[1]);
     return 0;
   }
   if (toInt(argv, 2, &numberOfSectors) == 0 || numberOfSectors < 0 ) {
-    serialPrint("%s: Invalid number of sectors \"%s\"", argv[0], argv[2]);
+    cliSerialPrint("%s: Invalid number of sectors \"%s\"", argv[0], argv[2]);
     return 0;
   }
 
   if (toInt(argv, 3, &bufferSectors) == 0 || bufferSectors < 0 ) {
-    serialPrint("%s: Invalid number of buffer sectors \"%s\"", argv[0], argv[3]);
+    cliSerialPrint("%s: Invalid number of buffer sectors \"%s\"", argv[0], argv[3]);
     return 0;
   }
 
   uint8_t * buffer = (uint8_t*) malloc(512*bufferSectors);
   if (!buffer) {
-    serialPrint("Not enough memory");
+    cliSerialPrint("Not enough memory");
     return 0;
   }
 
@@ -220,7 +266,7 @@ int cliReadSD(const char ** argv)
   while (numberOfSectors > 0) {
     DRESULT res = __disk_read(0, buffer, startSector, bufferSectors);
     if (res != RES_OK) {
-      serialPrint("disk_read error: %d, sector: %d(%d)", res, startSector, numberOfSectors);
+      cliSerialPrint("disk_read error: %d, sector: %d(%d)", res, startSector, numberOfSectors);
     }
 #if 0
     for(uint32_t n=0; n<bufferSectors; ++n) {
@@ -233,7 +279,7 @@ int cliReadSD(const char ** argv)
     for(int n=0; n<(bufferSectors*512); ++n) {
       summ += buffer[n];
     }
-    serialPrint("sector %d(%d) checksumm: %u", startSector, numberOfSectors, summ);
+    cliSerialPrint("sector %d(%d) checksumm: %u", startSector, numberOfSectors, summ);
 #endif
     if (numberOfSectors >= bufferSectors) {
       numberOfSectors -= bufferSectors;
@@ -247,7 +293,7 @@ int cliReadSD(const char ** argv)
   uint32_t elapsedTime = (get_tmr10ms() - start) * 10;
   if (elapsedTime == 0) elapsedTime = 1;
   uint32_t speed = bytesRead / elapsedTime;
-  serialPrint("Read %d bytes in %d ms, speed %d kB/s", bytesRead, elapsedTime, speed);
+  cliSerialPrint("Read %d bytes in %d ms, speed %d kB/s", bytesRead, elapsedTime, speed);
   free(buffer);
   return 0;
 }
@@ -259,67 +305,67 @@ int cliTestSD(const char ** argv)
   // get sector count
   uint32_t sectorCount;
   if (disk_ioctl(0, GET_SECTOR_COUNT, &sectorCount) != RES_OK) {
-    serialPrint("Error: can't read sector count");
+    cliSerialPrint("Error: can't read sector count");
     return 0;
   }
-  serialPrint("SD card has %u sectors", sectorCount);
+  cliSerialPrint("SD card has %u sectors", sectorCount);
 
   // read last 16 sectors one sector at the time
-  serialPrint("Starting single sector read test, reading 16 sectors one by one");
+  cliSerialPrint("Starting single sector read test, reading 16 sectors one by one");
   uint8_t * buffer = (uint8_t*) malloc(512);
   if (!buffer) {
-    serialPrint("Not enough memory");
+    cliSerialPrint("Not enough memory");
     return 0;
   }
   for (uint32_t s = sectorCount - 16; s<sectorCount; ++s) {
     DRESULT res = __disk_read(0, buffer, s, 1);
     if (res != RES_OK) {
-      serialPrint("sector %d read FAILED, err: %d", s, res);
+      cliSerialPrint("sector %d read FAILED, err: %d", s, res);
     }
     else {
-      serialPrint("sector %d read OK", s);
+      cliSerialPrint("sector %d read OK", s);
     }
   }
   free(buffer);
-  serialCrlf();
+  cliSerialCrlf();
 
   // read last 16 sectors, two sectors at the time with a multi-block read
   buffer = (uint8_t *) malloc(512*2);
   if (!buffer) {
-    serialPrint("Not enough memory");
+    cliSerialPrint("Not enough memory");
     return 0;
   }
 
-  serialPrint("Starting multiple sector read test, reading two sectors at the time");
+  cliSerialPrint("Starting multiple sector read test, reading two sectors at the time");
   for (uint32_t s = sectorCount - 16; s<sectorCount; s+=2) {
     DRESULT res = __disk_read(0, buffer, s, 2);
     if (res != RES_OK) {
-      serialPrint("sector %d-%d read FAILED, err: %d", s, s+1, res);
+      cliSerialPrint("sector %d-%d read FAILED, err: %d", s, s+1, res);
     }
     else {
-      serialPrint("sector %d-%d read OK", s, s+1);
+      cliSerialPrint("sector %d-%d read OK", s, s+1);
     }
   }
   free(buffer);
-  serialCrlf();
+  cliSerialCrlf();
 
   // read last 16 sectors, all sectors with single multi-block read
   buffer = (uint8_t*) malloc(512*16);
   if (!buffer) {
-    serialPrint("Not enough memory");
+    cliSerialPrint("Not enough memory");
     return 0;
   }
 
-  serialPrint("Starting multiple sector read test, reading 16 sectors at the time");
+  cliSerialPrint("Starting multiple sector read test, reading 16 sectors at the time");
   DRESULT res = __disk_read(0, buffer, sectorCount-16, 16);
   if (res != RES_OK) {
-    serialPrint("sector %d-%d read FAILED, err: %d", sectorCount-16, sectorCount-1, res);
+    cliSerialPrint("sector %d-%d read FAILED, err: %d", sectorCount-16, sectorCount-1, res);
   }
   else {
-    serialPrint("sector %d-%d read OK", sectorCount-16, sectorCount-1);
+    cliSerialPrint("sector %d-%d read OK", sectorCount-16, sectorCount-1);
   }
   free(buffer);
-  serialCrlf();
+  cliSerialCrlf();
 
   return 0;
 }
@@ -327,42 +373,42 @@ int cliTestSD(const char ** argv)
 int cliTestNew()
 {
   char * tmp = 0;
-  serialPrint("Allocating 1kB with new()");
+  cliSerialPrint("Allocating 1kB with new()");
   RTOS_WAIT_MS(200);
   tmp = new char[1024];
   if (tmp) {
-    serialPrint("\tsuccess");
+    cliSerialPrint("\tsuccess");
     delete[] tmp;
     tmp = 0;
   }
   else {
-    serialPrint("\tFAILURE");
+    cliSerialPrint("\tFAILURE");
   }
 
-  serialPrint("Allocating 10MB with (std::nothrow) new()");
+  cliSerialPrint("Allocating 10MB with (std::nothrow) new()");
   RTOS_WAIT_MS(200);
   tmp = new (std::nothrow) char[1024*1024*10];
   if (tmp) {
-    serialPrint("\tFAILURE, tmp = %p", tmp);
+    cliSerialPrint("\tFAILURE, tmp = %p", tmp);
     delete[] tmp;
     tmp = 0;
   }
   else {
-    serialPrint("\tsuccess, allocaton failed, tmp = 0");
+    cliSerialPrint("\tsuccess, allocaton failed, tmp = 0");
   }
 
-  serialPrint("Allocating 10MB with new()");
+  cliSerialPrint("Allocating 10MB with new()");
   RTOS_WAIT_MS(200);
   tmp = new char[1024*1024*10];
   if (tmp) {
-    serialPrint("\tFAILURE, tmp = %p", tmp);
+    cliSerialPrint("\tFAILURE, tmp = %p", tmp);
     delete[] tmp;
     tmp = 0;
   }
   else {
-    serialPrint("\tsuccess, allocaton failed, tmp = 0");
+    cliSerialPrint("\tsuccess, allocaton failed, tmp = 0");
   }
-  serialPrint("Test finished");
+  cliSerialPrint("Test finished");
   return 0;
 }
 
@@ -444,7 +490,7 @@ float runTimedFunctionTest(timedTestFunc_t func, const char *name,
     noRuns += step;
   }
   const float result = (noRuns * 500.0f) / (float)actualRuntime;  // runs/second
-  serialPrint("Test %s speed: %lu.%02u, (%lu runs in %lu ms)", name,
+  cliSerialPrint("Test %s speed: %lu.%02u, (%lu runs in %lu ms)", name,
               uint32_t(result), uint16_t((result - uint32_t(result)) * 100.0f),
               noRuns, actualRuntime);
   RTOS_WAIT_MS(200);
@@ -453,7 +499,7 @@ float runTimedFunctionTest(timedTestFunc_t func, const char *name,
 
 int cliTestGraphics()
 {
-  serialPrint("Starting graphics performance test...");
+  cliSerialPrint("Starting graphics performance test...");
   RTOS_WAIT_MS(200);
 
   watchdogSuspend(6000 /*60s*/);
@@ -479,7 +525,7 @@ int cliTestGraphics()
   result += RUN_GRAPHICS_TEST(testDrawTextVertical, 1000);
   result += RUN_GRAPHICS_TEST(testClear, 1000);
 
-  serialPrint("Total speed: %lu.%02u", uint32_t(result),
+  cliSerialPrint("Total speed: %lu.%02u", uint32_t(result),
               uint16_t((result - uint32_t(result)) * 100.0f));
 
   perMainEnabled = true;
@@ -586,7 +632,7 @@ void testMemoryCopyFrom_SDRAM_to_SDRAM_8bit()
 
 int cliTestMemorySpeed()
 {
-  serialPrint("Starting memory speed test...");
+  cliSerialPrint("Starting memory speed test...");
   RTOS_WAIT_MS(200);
 
   watchdogSuspend(6000 /*60s*/);
@@ -607,7 +653,7 @@ int cliTestMemorySpeed()
   result += RUN_MEMORY_TEST(testMemoryCopyFrom_SDRAM_to_SDRAM_32bit, 200);
 
   LTDC_Cmd(DISABLE);
-  serialPrint("Disabling LCD...");
+  cliSerialPrint("Disabling LCD...");
   RTOS_WAIT_MS(200);
 
   result += RUN_MEMORY_TEST(testMemoryReadFrom_RAM_8bit, 200);
@@ -619,7 +665,7 @@ int cliTestMemorySpeed()
   result += RUN_MEMORY_TEST(testMemoryCopyFrom_SDRAM_to_SDRAM_8bit, 200);
   result += RUN_MEMORY_TEST(testMemoryCopyFrom_SDRAM_to_SDRAM_32bit, 200);
 
-  serialPrint("Total speed: %lu.%02u", uint32_t(result),
+  cliSerialPrint("Total speed: %lu.%02u", uint32_t(result),
               uint16_t((result - uint32_t(result)) * 100.0f));
 
   LTDC_Cmd(ENABLE);
@@ -646,7 +692,7 @@ int cliTestModelsList()
 
   int count = 0;
 
-  serialPrint("Starting fetching RF data 100x...");
+  cliSerialPrint("Starting fetching RF data 100x...");
   const uint32_t start = RTOS_GET_MS();
 
   const list<ModelsCategory *> &cats = modList.getCategories();
@@ -656,7 +702,7 @@ int cliTestModelsList()
       for (ModelsCategory::iterator mod_it = (*cat_it)->begin();
            mod_it != (*cat_it)->end(); mod_it++) {
         if (!(*mod_it)->fetchRfData()) {
-          serialPrint("Error while fetching RF data...");
+          cliSerialPrint("Error while fetching RF data...");
           return 0;
         }
 
@@ -666,7 +712,7 @@ int cliTestModelsList()
   }
 
 done:
-  serialPrint("Done fetching %ix RF data: %lu ms", count,
+  cliSerialPrint("Done fetching %ix RF data: %lu ms", count,
               (RTOS_GET_MS() - start));
 
   return 0;
@@ -699,7 +745,7 @@ int cliTest(const char ** argv)
 #endif
 #endif
   else {
-    serialPrint("%s: Invalid argument \"%s\"", argv[0], argv[1]);
+    cliSerialPrint("%s: Invalid argument \"%s\"", argv[0], argv[1]);
   }
   return 0;
 }
@@ -713,18 +759,18 @@ int cliTrace(const char ** argv)
     cliTracesEnabled = false;
   }
   else {
-    serialPrint("%s: Invalid argument \"%s\"", argv[0], argv[1]);
+    cliSerialPrint("%s: Invalid argument \"%s\"", argv[0], argv[1]);
   }
   return 0;
 }
 
 int cliStackInfo(const char ** argv)
 {
-  serialPrint("[MAIN] %d available / %d bytes", stackAvailable()*4, stackSize()*4);
-  serialPrint("[MENUS] %d available / %d bytes", menusStack.available()*4, menusStack.size());
-  serialPrint("[MIXER] %d available / %d bytes", mixerStack.available()*4, mixerStack.size());
-  serialPrint("[AUDIO] %d available / %d bytes", audioStack.available()*4, audioStack.size());
-  serialPrint("[CLI] %d available / %d bytes", cliStack.available()*4, cliStack.size());
+  cliSerialPrint("[MAIN] %d available / %d bytes", stackAvailable()*4, stackSize()*4);
+  cliSerialPrint("[MENUS] %d available / %d bytes", menusStack.available()*4, menusStack.size());
+  cliSerialPrint("[MIXER] %d available / %d bytes", mixerStack.available()*4, mixerStack.size());
+  cliSerialPrint("[AUDIO] %d available / %d bytes", audioStack.available()*4, audioStack.size());
+  cliSerialPrint("[CLI] %d available / %d bytes", cliStack.available()*4, cliStack.size());
   return 0;
 }
 
@@ -747,31 +793,31 @@ int cliMemoryInfo(const char ** argv)
   //   int keepcost; /* top-most, releasable (via malloc_trim) space */
   // };
   struct mallinfo info = mallinfo();
-  serialPrint("mallinfo:");
-  serialPrint("\tarena    %d bytes", info.arena);
-  serialPrint("\tordblks  %d bytes", info.ordblks);
-  serialPrint("\tuordblks %d bytes", info.uordblks);
-  serialPrint("\tfordblks %d bytes", info.fordblks);
-  serialPrint("\tkeepcost %d bytes", info.keepcost);
+  cliSerialPrint("mallinfo:");
+  cliSerialPrint("\tarena    %d bytes", info.arena);
+  cliSerialPrint("\tordblks  %d bytes", info.ordblks);
+  cliSerialPrint("\tuordblks %d bytes", info.uordblks);
+  cliSerialPrint("\tfordblks %d bytes", info.fordblks);
+  cliSerialPrint("\tkeepcost %d bytes", info.keepcost);
 
-  serialPrint("\nHeap:");
-  serialPrint("\tstart %p", (unsigned char *)&_end);
-  serialPrint("\tend   %p", (unsigned char *)&_heap_end);
-  serialPrint("\tcurr  %p", heap);
-  serialPrint("\tused  %d bytes", (int)(heap - (unsigned char *)&_end));
-  serialPrint("\tfree  %d bytes", (int)((unsigned char *)&_heap_end - heap));
+  cliSerialPrint("\nHeap:");
+  cliSerialPrint("\tstart %p", (unsigned char *)&_end);
+  cliSerialPrint("\tend   %p", (unsigned char *)&_heap_end);
+  cliSerialPrint("\tcurr  %p", heap);
+  cliSerialPrint("\tused  %d bytes", (int)(heap - (unsigned char *)&_end));
+  cliSerialPrint("\tfree  %d bytes", (int)((unsigned char *)&_heap_end - heap));
 
 #if defined(LUA)
-  serialPrint("\nLua:");
+  cliSerialPrint("\nLua:");
   uint32_t s = luaGetMemUsed(lsScripts);
-  serialPrint("\tScripts %u", s);
+  cliSerialPrint("\tScripts %u", s);
 #if defined(COLORLCD)
   uint32_t w = luaGetMemUsed(lsWidgets);
   uint32_t e = luaExtraMemoryUsage;
-  serialPrint("\tWidgets %u", w);
-  serialPrint("\tExtra   %u", e);
-  serialPrint("------------");
-  serialPrint("\tTotal   %u", s + w + e);
+  cliSerialPrint("\tWidgets %u", w);
+  cliSerialPrint("\tExtra   %u", e);
+  cliSerialPrint("------------");
+  cliSerialPrint("\tTotal   %u", s + w + e);
 #endif
 #endif
   return 0;
@@ -825,7 +871,7 @@ int cliSet(const char **argv)
       g_rtcTime = gmktime(&t);
       rtcSetTime(&t);
     } else {
-      serialPrint("%s: Invalid arguments \"%s\" \"%s\"", argv[0], argv[1],
+      cliSerialPrint("%s: Invalid arguments \"%s\" \"%s\"", argv[0], argv[1],
                   argv[2]);
       return -1;
     }
@@ -836,7 +882,7 @@ int cliSet(const char **argv)
     if (toInt(argv, 2, &level) > 0) {
       setVolume(level);
     } else {
-      serialPrint("%s: Invalid argument \"%s\" \"%s\"", argv[0], argv[1],
+      cliSerialPrint("%s: Invalid argument \"%s\" \"%s\"", argv[0], argv[1],
                   argv[2]);
       return -1;
     }
@@ -845,7 +891,7 @@ int cliSet(const char **argv)
   else if (!strcmp(argv[1], "rfmod")) {
     int module = 0;
     if (toInt(argv, 2, &module) < 0) {
-      serialPrint("%s: invalid module argument '%s'", argv[0], argv[2]);
+      cliSerialPrint("%s: invalid module argument '%s'", argv[0], argv[2]);
       return -1;
     }
     if (!strcmp(argv[3], "power")) {
@@ -862,34 +908,34 @@ int cliSet(const char **argv)
           EXTERNAL_MODULE_OFF();
         }
       } else {
-        serialPrint("%s: invalid power argument '%s'", argv[0], argv[4]);
+        cliSerialPrint("%s: invalid power argument '%s'", argv[0], argv[4]);
         return -1;
       }
-      serialPrint("%s: rfmod %d power %s", argv[0], module, argv[4]);
+      cliSerialPrint("%s: rfmod %d power %s", argv[0], module, argv[4]);
     }
 #if defined(INTMODULE_BOOTCMD_GPIO)
     else if (!strcmp(argv[3], "bootpin")) {
       int level = 0;
       if (toInt(argv, 4, &level) < 0) {
-        serialPrint("%s: invalid bootpin argument '%s'", argv[0], argv[4]);
+        cliSerialPrint("%s: invalid bootpin argument '%s'", argv[0], argv[4]);
         return -1;
       }
       if (module == 0) {
         if (level) {
           GPIO_SetBits(INTMODULE_BOOTCMD_GPIO, INTMODULE_BOOTCMD_GPIO_PIN);
-          serialPrint("%s: bootpin set", argv[0]);
+          cliSerialPrint("%s: bootpin set", argv[0]);
         } else {
           GPIO_ResetBits(INTMODULE_BOOTCMD_GPIO, INTMODULE_BOOTCMD_GPIO_PIN);
-          serialPrint("%s: bootpin reset", argv[0]);
+          cliSerialPrint("%s: bootpin reset", argv[0]);
         }
       }
     }
 #endif
     else {
       if (strlen(argv[2]) == 0) {
-        serialPrint("%s: missing rfmod arguments", argv[0]);
+        cliSerialPrint("%s: missing rfmod arguments", argv[0]);
       } else {
-        serialPrint("%s: invalid rfmod argument '%s'", argv[0], argv[3]);
+        cliSerialPrint("%s: invalid rfmod argument '%s'", argv[0], argv[3]);
         return -1;
       }
     }
@@ -897,15 +943,15 @@ int cliSet(const char **argv)
   else if (!strcmp(argv[1], "pulses")) {
     int level = 0;
     if (toInt(argv, 2, &level) < 0) {
-      serialPrint("%s: invalid level argument '%s'", argv[0], argv[2]);
+      cliSerialPrint("%s: invalid level argument '%s'", argv[0], argv[2]);
       return -1;
     }
 
     if (level) {
-      serialPrint("%s: pulses start", argv[0]);
+      cliSerialPrint("%s: pulses start", argv[0]);
       startPulses();
     } else {
-      serialPrint("%s: pulses stop", argv[0]);
+      cliSerialPrint("%s: pulses stop", argv[0]);
       stopPulses();
     }
   }
@@ -917,7 +963,7 @@ int cliSet(const char **argv)
 static void spInternalModuleTx(uint8_t* buf, uint32_t len)
 {
   while (len > 0) {
-    IntmoduleSerialDriver.sendByte(*(buf++));
+    IntmoduleSerialDriver.sendByte(nullptr, *(buf++));
     len--;
   }
 }
@@ -928,8 +974,6 @@ static const etx_serial_init spIntmoduleSerialInitParams = {
   .stop_bits = ETX_StopBits_One,
   .word_length = ETX_WordLength_8,
   .rx_enable = true,
-  .rx_dma_buf = nullptr,
-  .rx_dma_buf_len = 0,
   .on_receive = intmoduleFifoReceive,
   .on_error = intmoduleFifoError,
 };
@@ -953,7 +997,7 @@ int cliSerialPassthrough(const char **argv)
 
   // 3rd argument (baudrate is optional)
   if (!port_type || !port_num) {
-    serialPrint("%s: missing argument", argv[0]);
+    cliSerialPrint("%s: missing argument", argv[0]);
     return -1;
   }
 
@@ -961,7 +1005,7 @@ int cliSerialPassthrough(const char **argv)
   int err = toInt(argv, 2, &port_n);
   if (err == -1) return err;
   if (err == 0) {
-    serialPrint("%s: missing port #", argv[0]);
+    cliSerialPrint("%s: missing port #", argv[0]);
     return -1;
   }
 
@@ -973,7 +1017,7 @@ int cliSerialPassthrough(const char **argv)
     if (!baudrate) {
       // default to 115200
       baudrate = 115200;
-      serialPrint("%s: USB baudrate is 0, default to 115200", argv[0]);
+      cliSerialPrint("%s: USB baudrate is 0, default to 115200", argv[0]);
     }
   }
 
@@ -982,7 +1026,7 @@ int cliSerialPassthrough(const char **argv)
     if (port_n >= NUM_MODULES
         // only internal module supported for now
         && port_n != INTERNAL_MODULE) {
-      serialPrint("%s: invalid port # '%s'", port_num);
+      cliSerialPrint("%s: invalid port # '%s'", port_num);
       return -1;
     }
     
@@ -1002,7 +1046,7 @@ int cliSerialPassthrough(const char **argv)
       etx_serial_init params(spIntmoduleSerialInitParams);
       params.baudrate = baudrate;
 
-      IntmoduleSerialDriver.init(&params);
+      void* uart_ctx = IntmoduleSerialDriver.init(&params);
 
       // backup and swap CLI input
       auto backupCB = cliReceiveCallBack;
@@ -1023,7 +1067,7 @@ int cliSerialPassthrough(const char **argv)
             timeout--;
           }
 
-          usbSerialPutc(data);
+          usbSerialPutc(nullptr, data);
         }
 
         // keep us up & running
@@ -1035,7 +1079,7 @@ int cliSerialPassthrough(const char **argv)
       cliReceiveCallBack = backupCB;
 
       // and stop module
-      IntmoduleSerialDriver.deinit();
+      IntmoduleSerialDriver.deinit(uart_ctx);
 
       // power off the module and wait for a bit
       INTERNAL_MODULE_OFF();
@@ -1053,7 +1097,7 @@ int cliSerialPassthrough(const char **argv)
     xTaskResumeAll();
     
   } else {
-    serialPrint("%s: invalid port type '%s'", port_type);
+    cliSerialPrint("%s: invalid port type '%s'", port_type);
     return -1;
   }
   
@@ -1069,9 +1113,9 @@ void printInterrupts()
   memset(&interruptCounters, 0, sizeof(interruptCounters));
   interruptCounters.resetTime = get_tmr10ms();
   __enable_irq();
-  serialPrint("Interrupts count in the last %u ms:", (get_tmr10ms() - ic.resetTime) * 10);
+  cliSerialPrint("Interrupts count in the last %u ms:", (get_tmr10ms() - ic.resetTime) * 10);
   for(int n = 0; n < INT_LAST; n++) {
-    serialPrint("%s: %u", interruptNames[n], ic.cnt[n]);
+    cliSerialPrint("%s: %u", interruptNames[n], ic.cnt[n]);
   }
 }
 #endif //#if defined(DEBUG_INTERRUPTS)
@@ -1080,20 +1124,20 @@ void printInterrupts()
 void printDebugTime(uint32_t time)
 {
   if (time >= 30000) {
-    serialPrintf("%dms", time/1000);
+    cliSerialPrintf("%dms", time/1000);
   }
   else {
-    serialPrintf("%d.%03dms", time/1000, time%1000);
+    cliSerialPrintf("%d.%03dms", time/1000, time%1000);
   }
 }
 
 void printDebugTimer(const char * name, DebugTimer & timer)
 {
-  serialPrintf("%s: ", name);
+  cliSerialPrintf("%s: ", name);
   printDebugTime( timer.getMin());
-  serialPrintf(" - ");
+  cliSerialPrintf(" - ");
   printDebugTime(timer.getMax());
-  serialCrlf();
+  cliSerialCrlf();
   timer.reset();
 }
 void printDebugTimers()
@@ -1108,28 +1152,28 @@ void printDebugTimers()
 void printAudioVars()
 {
   for (int n = 0; n < AUDIO_BUFFER_COUNT; n++) {
-    serialPrint("Audio Buffer %d: size: %u, ", n,
+    cliSerialPrint("Audio Buffer %d: size: %u, ", n,
                 (uint32_t)audioBuffers[n].size);
     dump((uint8_t *)audioBuffers[n].data, 32);
   }
-  serialPrint("fragments:");
+  cliSerialPrint("fragments:");
   for (int n = 0; n < AUDIO_QUEUE_LENGTH; n++) {
-    serialPrint("%d: type %u: id: %u, repeat: %u, ", n,
+    cliSerialPrint("%d: type %u: id: %u, repeat: %u, ", n,
                 (uint32_t)audioQueue.fragmentsFifo.fragments[n].type,
                 (uint32_t)audioQueue.fragmentsFifo.fragments[n].id,
                 (uint32_t)audioQueue.fragmentsFifo.fragments[n].repeat);
     if (audioQueue.fragmentsFifo.fragments[n].type == FRAGMENT_FILE) {
-      serialPrint(" file: %s", audioQueue.fragmentsFifo.fragments[n].file);
+      cliSerialPrint(" file: %s", audioQueue.fragmentsFifo.fragments[n].file);
     }
   }
 
-  serialPrint("FragmentFifo:  ridx: %d, widx: %d",
+  cliSerialPrint("FragmentFifo:  ridx: %d, widx: %d",
               audioQueue.fragmentsFifo.ridx, audioQueue.fragmentsFifo.widx);
-  serialPrint("audioQueue:  readIdx: %d, writeIdx: %d, full: %d",
+  cliSerialPrint("audioQueue:  readIdx: %d, writeIdx: %d, full: %d",
               audioQueue.buffersFifo.readIdx, audioQueue.buffersFifo.writeIdx,
               audioQueue.buffersFifo.bufferFull);
 
-  serialPrint("normalContext: %u",
+  cliSerialPrint("normalContext: %u",
               (uint32_t)audioQueue.normalContext.fragment.type);
 }
 #endif
@@ -1152,13 +1196,13 @@ int cliDisplay(const char ** argv)
       uint8_t len = STR_VKEYS[0];
       strncpy(name, STR_VKEYS+1+len*i, len);
       name[len] = '\0';
-      serialPrint("[%s] = %s", name, keys[i].state() ? "on" : "off");
+      cliSerialPrint("[%s] = %s", name, keys[i].state() ? "on" : "off");
     }
 #if defined(ROTARY_ENCODER_NAVIGATION)
-    serialPrint("[Enc.] = %d", rotencValue / ROTARY_ENCODER_GRANULARITY);
+    cliSerialPrint("[Enc.] = %d", rotencValue / ROTARY_ENCODER_GRANULARITY);
 #endif
     for (int i=TRM_BASE; i<=TRM_LAST; i++) {
-      serialPrint("[Trim%d] = %s", i-TRM_BASE, keys[i].state() ? "on" : "off");
+      cliSerialPrint("[Trim%d] = %s", i-TRM_BASE, keys[i].state() ? "on" : "off");
     }
     for (int i=MIXSRC_FIRST_SWITCH; i<=MIXSRC_LAST_SWITCH; i++) {
       mixsrc_t sw = i - MIXSRC_FIRST_SWITCH;
@@ -1166,34 +1210,34 @@ int cliDisplay(const char ** argv)
         char swName[LEN_SWITCH_NAME + 1];
         strAppend(swName, STR_VSWITCHES+1+sw*STR_VSWITCHES[0], STR_VSWITCHES[0]);
         static const char * const SWITCH_POSITIONS[] = { "down", "mid", "up" };
-        serialPrint("[%s] = %s", swName, SWITCH_POSITIONS[1 + getValue(i) / 1024]);
+        cliSerialPrint("[%s] = %s", swName, SWITCH_POSITIONS[1 + getValue(i) / 1024]);
       }
     }
   }
   else if (!strcmp(argv[1], "adc")) {
     for (int i=0; i<NUM_ANALOGS; i++) {
-      serialPrint("adc[%d] = %04X", i, (int)adcValues[i]);
+      cliSerialPrint("adc[%d] = %04X", i, (int)adcValues[i]);
     }
   }
   else if (!strcmp(argv[1], "outputs")) {
     for (int i=0; i<MAX_OUTPUT_CHANNELS; i++) {
-      serialPrint("outputs[%d] = %04d", i, (int)channelOutputs[i]);
+      cliSerialPrint("outputs[%d] = %04d", i, (int)channelOutputs[i]);
     }
   }
   else if (!strcmp(argv[1], "rtc")) {
     struct gtm utm;
     gettime(&utm);
-    serialPrint("rtc = %4d-%02d-%02d %02d:%02d:%02d.%02d0", utm.tm_year+TM_YEAR_BASE, utm.tm_mon+1, utm.tm_mday, utm.tm_hour, utm.tm_min, utm.tm_sec, g_ms100);
+    cliSerialPrint("rtc = %4d-%02d-%02d %02d:%02d:%02d.%02d0", utm.tm_year+TM_YEAR_BASE, utm.tm_mon+1, utm.tm_mday, utm.tm_hour, utm.tm_min, utm.tm_sec, g_ms100);
   }
 #if !defined(SOFTWARE_VOLUME)
   else if (!strcmp(argv[1], "volume")) {
-    serialPrint("volume = %d", getVolume());
+    cliSerialPrint("volume = %d", getVolume());
   }
 #endif
   else if (!strcmp(argv[1], "uid")) {
     char str[LEN_CPU_UID+1];
     getCPUUniqueID(str);
-    serialPrint("uid = %s", str);
+    cliSerialPrint("uid = %s", str);
   }
   else if (!strcmp(argv[1], "tim")) {
     int timerNumber;
@@ -1215,29 +1259,29 @@ int cliDisplay(const char ** argv)
         default:
           return 0;
       }
-      serialPrint("TIM%d", timerNumber);
-      serialPrint(" CR1    0x%x", tim->CR1);
-      serialPrint(" CR2    0x%x", tim->CR2);
-      serialPrint(" DIER   0x%x", tim->DIER);
-      serialPrint(" SR     0x%x", tim->SR);
-      serialPrint(" EGR    0x%x", tim->EGR);
-      serialPrint(" CCMR1  0x%x", tim->CCMR1);
-      serialPrint(" CCMR2  0x%x", tim->CCMR2);
+      cliSerialPrint("TIM%d", timerNumber);
+      cliSerialPrint(" CR1    0x%x", tim->CR1);
+      cliSerialPrint(" CR2    0x%x", tim->CR2);
+      cliSerialPrint(" DIER   0x%x", tim->DIER);
+      cliSerialPrint(" SR     0x%x", tim->SR);
+      cliSerialPrint(" EGR    0x%x", tim->EGR);
+      cliSerialPrint(" CCMR1  0x%x", tim->CCMR1);
+      cliSerialPrint(" CCMR2  0x%x", tim->CCMR2);
 
-      serialPrint(" CNT    0x%x", tim->CNT);
-      serialPrint(" ARR    0x%x", tim->ARR);
-      serialPrint(" PSC    0x%x", tim->PSC);
+      cliSerialPrint(" CNT    0x%x", tim->CNT);
+      cliSerialPrint(" ARR    0x%x", tim->ARR);
+      cliSerialPrint(" PSC    0x%x", tim->PSC);
 
-      serialPrint(" CCER   0x%x", tim->CCER);
-      serialPrint(" CCR1   0x%x", tim->CCR1);
-      serialPrint(" CCR2   0x%x", tim->CCR2);
-      serialPrint(" CCR3   0x%x", tim->CCR3);
-      serialPrint(" CCR4   0x%x", tim->CCR4);
+      cliSerialPrint(" CCER   0x%x", tim->CCER);
+      cliSerialPrint(" CCR1   0x%x", tim->CCR1);
+      cliSerialPrint(" CCR2   0x%x", tim->CCR2);
+      cliSerialPrint(" CCR3   0x%x", tim->CCR3);
+      cliSerialPrint(" CCR4   0x%x", tim->CCR4);
     }
   }
   else if (!strcmp(argv[1], "dma")) {
-    serialPrint("DMA1_Stream7");
-    serialPrint(" CR    0x%x", DMA1_Stream7->CR);
+    cliSerialPrint("DMA1_Stream7");
+    cliSerialPrint(" CR    0x%x", DMA1_Stream7->CR);
   }
 #if defined(DEBUG_INTERRUPTS)
   else if (!strcmp(argv[1], "int")) {
@@ -1258,7 +1302,7 @@ int cliDisplay(const char ** argv)
   else if (!strcmp(argv[1], "dc")) {
     DiskCacheStats stats = diskCache.getStats();
     uint32_t hitRate = diskCache.getHitRate();
-    serialPrint("Disk Cache stats: w:%u r: %u, h: %u(%0.1f%%), m: %u", stats.noWrites, (stats.noHits + stats.noMisses), stats.noHits, hitRate*0.1f, stats.noMisses);
+    cliSerialPrint("Disk Cache stats: w:%u r: %u, h: %u(%0.1f%%), m: %u", stats.noWrites, (stats.noHits + stats.noMisses), stats.noHits, hitRate*0.1f, stats.noMisses);
   }
 #endif
   else if (toLongLongInt(argv, 1, &address) > 0) {
@@ -1275,15 +1319,15 @@ int cliDebugVars(const char ** argv)
 #if defined(PCBHORUS)
   extern uint32_t ioMutexReq, ioMutexRel;
   extern uint32_t sdReadRetries;
-  serialPrint("ioMutexReq=%d", ioMutexReq);
-  serialPrint("ioMutexRel=%d", ioMutexRel);
-  serialPrint("sdReadRetries=%d", sdReadRetries);
+  cliSerialPrint("ioMutexReq=%d", ioMutexReq);
+  cliSerialPrint("ioMutexRel=%d", ioMutexRel);
+  cliSerialPrint("sdReadRetries=%d", sdReadRetries);
 #if defined(ACCESS_DENIED)
   extern volatile int32_t authenticateFrames;
-  serialPrint("authenticateFrames=%d", authenticateFrames);
+  cliSerialPrint("authenticateFrames=%d", authenticateFrames);
 #endif
 #elif defined(PCBTARANIS)
-  serialPrint("telemetryErrors=%d", telemetryErrors);
+  cliSerialPrint("telemetryErrors=%d", telemetryErrors);
 #endif
 
   return 0;
@@ -1311,7 +1355,7 @@ int cliRepeat(const char ** argv)
     }
   }
   else {
-    serialPrint("%s: Invalid arguments", argv[0]);
+    cliSerialPrint("%s: Invalid arguments", argv[0]);
   }
   return 0;
 }
@@ -1320,13 +1364,13 @@ int cliRepeat(const char ** argv)
 #if defined(JITTER_MEASURE)
 int cliShowJitter(const char ** argv)
 {
-  serialPrint(  "#   anaIn   rawJ   avgJ");
+  cliSerialPrint(  "#   anaIn   rawJ   avgJ");
   for (int i=0; i<NUM_ANALOGS; i++) {
-    serialPrint("A%02d %04X %04X %3d %3d", i, getAnalogValue(i), anaIn(i), rawJitter[i].get(), avgJitter[i].get());
+    cliSerialPrint("A%02d %04X %04X %3d %3d", i, getAnalogValue(i), anaIn(i), rawJitter[i].get(), avgJitter[i].get());
     if (IS_POT_MULTIPOS(i)) {
       StepsCalibData * calib = (StepsCalibData *) &g_eeGeneral.calib[i];
       for (int j=0; j<calib->count; j++) {
-        serialPrint("    s%d %04X", j, calib->steps[j]);
+        cliSerialPrint("    s%d %04X", j, calib->steps[j]);
       }
     }
   }
@@ -1350,10 +1394,10 @@ int cliGps(const char ** argv)
 #endif
   else if (toInt(argv, 1, &baudrate) > 0 && baudrate > 0) {
     gpsInit(baudrate);
-    serialPrint("GPS baudrate set to %d", baudrate);
+    cliSerialPrint("GPS baudrate set to %d", baudrate);
   }
   else {
-    serialPrint("%s: Invalid arguments", argv[0]);
+    cliSerialPrint("%s: Invalid arguments", argv[0]);
   }
   return 0;
 }
@@ -1366,21 +1410,21 @@ int cliBlueTooth(const char ** argv)
   if (!strncmp(argv[1], "AT", 2) || !strncmp(argv[1], "TTM", 3)) {
     bluetooth.writeString(argv[1]);
     char * line = bluetooth.readline();
-    serialPrint("<BT %s", line);
+    cliSerialPrint("<BT %s", line);
   }
   else if (toInt(argv, 1, &baudrate) > 0) {
     if (baudrate > 0) {
       bluetoothInit(baudrate, true);
       char * line = bluetooth.readline();
-      serialPrint("<BT %s", line);
+      cliSerialPrint("<BT %s", line);
     }
     else {
       bluetoothDisable();
-      serialPrint("BT turned off");
+      cliSerialPrint("BT turned off");
     }
   }
   else {
-    serialPrint("%s: Invalid arguments", argv[0]);
+    cliSerialPrint("%s: Invalid arguments", argv[0]);
   }
   return 0;
 }
@@ -1407,7 +1451,7 @@ int cliCrypt(const char ** argv)
     return -1;
 
   strncpy((char*)cryptInput, argv[1], sizeof(cryptInput));
-  serialPrint("Input:");
+  cliSerialPrint("Input:");
   dumpBody(cryptInput, sizeof(cryptInput));
   dumpEnd();
 
@@ -1420,9 +1464,9 @@ int cliCrypt(const char ** argv)
 
   uint32_t startMs = RTOS_GET_MS();
   testAccessDenied(100000);
-  serialPrintf("access_denied: %f us/run\r\n", (RTOS_GET_MS() - startMs)*1000.0f / 100000.0f);
+  cliSerialPrintf("access_denied: %f us/run\r\n", (RTOS_GET_MS() - startMs)*1000.0f / 100000.0f);
 
-  serialPrint("Decrypted (SW):");
+  cliSerialPrint("Decrypted (SW):");
   dumpBody(cryptOutput, sizeof(cryptOutput));
   dumpEnd();
 
@@ -1479,14 +1523,14 @@ int cliHelp(const char ** argv)
 {
   for (const CliCommand * command = cliCommands; command->name != nullptr; command++) {
     if (argv[1][0] == '\0' || !strcmp(command->name, argv[0])) {
-      serialPrint("%s %s", command->name, command->args);
+      cliSerialPrint("%s %s", command->name, command->args);
       if (argv[1][0] != '\0') {
         return 0;
       }
     }
   }
   if (argv[1][0] != '\0') {
-    serialPrint("Invalid command \"%s\"", argv[0]);
+    cliSerialPrint("Invalid command \"%s\"", argv[0]);
   }
   return -1;
 }
@@ -1501,7 +1545,7 @@ int cliExecCommand(const char ** argv)
       return command->func(argv);
     }
   }
-  serialPrint("Invalid command \"%s\"", argv[0]);
+  cliSerialPrint("Invalid command \"%s\"", argv[0]);
   return -1;
 }
 
@@ -1556,14 +1600,14 @@ void cliTask(void * pdata)
     switch(c) {
     case CHAR_NEWPAGE:
       // clear screen
-      serialPrint("\033[2J\033[1;1H");
+      cliSerialPrint("\033[2J\033[1;1H");
       cliPrompt();
       break;
 
     case CHAR_BACKSPACE:
       if (pos) {
         line[--pos] = '\0';
-        serialPutc(c);
+        cliSerialPutc(c);
       }
       break;
 
@@ -1573,7 +1617,7 @@ void cliTask(void * pdata)
 
     case CHAR_LF:
       // enter
-      serialCrlf();
+      cliSerialCrlf();
       line[pos] = '\0';
       if (pos == 0 && cliLastLine[0]) {
         // execute (repeat) last command
@@ -1592,7 +1636,7 @@ void cliTask(void * pdata)
     default:
       if (isascii(c) && pos < CLI_COMMAND_MAX_LEN) {
         line[pos++] = c;
-        serialPutc(c);
+        cliSerialPutc(c);
       }
       break;
     }
diff --git a/radio/src/cli.h b/radio/src/cli.h
index 73f71b1e4..9a8803852 100644
--- a/radio/src/cli.h
+++ b/radio/src/cli.h
@@ -35,4 +35,7 @@ void cliStart();
 // Called from receive ISR (either USB or UART)
 void cliReceiveData(uint8_t* buf, uint32_t len);
 
+// Set callbacks for sending data back to serial port
+void cliSetSendCb(void* ctx, void (*cb)(void*, uint8_t));
+
 #endif // _CLI_H_
diff --git a/radio/src/dataconstants.h b/radio/src/dataconstants.h
index 1d5e00e20..ea18eeee5 100644
--- a/radio/src/dataconstants.h
+++ b/radio/src/dataconstants.h
@@ -241,9 +241,6 @@ enum TrainerMode {
 
 enum UartModes {
   UART_MODE_NONE,
-#if defined(CLI) || defined(DEBUG)
-  UART_MODE_DEBUG SKIP = UART_MODE_NONE,
-#endif
   UART_MODE_TELEMETRY_MIRROR,
   UART_MODE_TELEMETRY,
   UART_MODE_SBUS_TRAINER,
@@ -252,9 +249,7 @@ enum UartModes {
   UART_MODE_MAX SKIP = UART_MODE_COUNT-1
 };
 
-#if defined(CLI) || defined(DEBUG)
-#define UART_MODE_NONE UART_MODE_DEBUG
-#endif
+#define UART_MODE_DEBUG UART_MODE_NONE
 
 #define LEN_SWITCH_NAME    3
 #define LEN_ANA_NAME       3
diff --git a/radio/src/debug.h b/radio/src/debug.h
index c696e3755..3c6b9b1f2 100644
--- a/radio/src/debug.h
+++ b/radio/src/debug.h
@@ -33,9 +33,6 @@
 
 extern volatile uint32_t g_tmr10ms;
 
-uint8_t auxSerialTracesEnabled();
-uint8_t aux2SerialTracesEnabled();
-
 #if defined(SIMU)
   typedef void (*traceCallbackFunc)(const char * text);
   extern traceCallbackFunc traceCallback;
@@ -45,9 +42,9 @@ uint8_t aux2SerialTracesEnabled();
   #define debugPrintf(...) printf(__VA_ARGS__)
 #elif defined(DEBUG) && defined(CLI)
   #include "cli_traces.h"
-  #define debugPrintf(...) do { if (cliTracesEnabled) serialPrintf(__VA_ARGS__); } while(0)
+  #define debugPrintf(...) do { if (cliTracesEnabled) dbgSerialPrintf(__VA_ARGS__); } while(0)
 #elif defined(DEBUG)
-  #define debugPrintf(...) do { serialPrintf(__VA_ARGS__); } while(0)
+  #define debugPrintf(...) do { dbgSerialPrintf(__VA_ARGS__); } while(0)
 #else
   #define debugPrintf(...)
 #endif
diff --git a/radio/src/dump.cpp b/radio/src/dump.cpp
index 25ef48901..ecb439524 100644
--- a/radio/src/dump.cpp
+++ b/radio/src/dump.cpp
@@ -24,7 +24,7 @@
 #if defined(SIMU)
 #define dumpPrintf(...) debugPrintf(__VA_ARGS__)
 #else
-#define dumpPrintf(...) serialPrintf(__VA_ARGS__)
+#define dumpPrintf(...) dbgSerialPrintf(__VA_ARGS__)
 #endif
 
 #if defined(DEBUG) || defined(CLI)
diff --git a/radio/src/gui/212x64/view_statistics.cpp b/radio/src/gui/212x64/view_statistics.cpp
index fc1cb4cbc..270c80807 100644
--- a/radio/src/gui/212x64/view_statistics.cpp
+++ b/radio/src/gui/212x64/view_statistics.cpp
@@ -163,18 +163,6 @@ void menuStatisticsDebug(event_t event)
 
   uint8_t y = FH + 1;
 
-#if defined(STM32) && !defined(SIMU) && defined(DEBUG)
-  lcdDrawTextAlignedLeft(y, "Usb");
-  lcdDrawNumber(MENU_DEBUG_COL1_OFS, y, charsWritten, LEFT);
-  lcdDrawText(lcdLastRightPos, y, " ");
-  lcdDrawNumber(lcdLastRightPos, y, APP_Rx_ptr_in, LEFT);
-  lcdDrawText(lcdLastRightPos, y, " ");
-  lcdDrawNumber(lcdLastRightPos, y, APP_Rx_ptr_out, LEFT);
-  lcdDrawText(lcdLastRightPos, y, " ");
-  lcdDrawNumber(lcdLastRightPos, y, usbWraps, LEFT);
-  y += FH;
-#endif
-
 #if defined(STM32)
   lcdDrawTextAlignedLeft(y, "Free Mem");
   lcdDrawNumber(MENU_DEBUG_COL1_OFS, y, availableMemory(), LEFT);
diff --git a/radio/src/gui/colorlcd/radio_hardware.cpp b/radio/src/gui/colorlcd/radio_hardware.cpp
index d91fa2627..abed9ea46 100644
--- a/radio/src/gui/colorlcd/radio_hardware.cpp
+++ b/radio/src/gui/colorlcd/radio_hardware.cpp
@@ -380,7 +380,7 @@ void RadioHardwarePage::build(FormWindow * window)
                  UART_MODE_MAX, GET_DEFAULT(g_eeGeneral.auxSerialMode),
                  [](int value) {
                    g_eeGeneral.auxSerialMode = value;
-                   auxSerialInit(g_eeGeneral.auxSerialMode, modelTelemetryProtocol());
+                   serialInit(0, value);
                    SET_DIRTY();
                  });
   aux->setAvailableHandler(isAuxModeAvailable);
@@ -394,7 +394,7 @@ void RadioHardwarePage::build(FormWindow * window)
                  UART_MODE_MAX, GET_DEFAULT(g_eeGeneral.aux2SerialMode),
                  [](int value) {
                    g_eeGeneral.aux2SerialMode = value;
-                   aux2SerialInit(g_eeGeneral.aux2SerialMode, modelTelemetryProtocol());
+                   serialInit(1, value);
                    SET_DIRTY();
                  });
   aux2->setAvailableHandler(isAux2ModeAvailable);
diff --git a/radio/src/gui/common/stdlcd/radio_hardware.cpp b/radio/src/gui/common/stdlcd/radio_hardware.cpp
index 6aa47af37..ffa2dadd5 100644
--- a/radio/src/gui/common/stdlcd/radio_hardware.cpp
+++ b/radio/src/gui/common/stdlcd/radio_hardware.cpp
@@ -600,7 +600,7 @@ void menuRadioHardware(event_t event)
       case ITEM_RADIO_HARDWARE_AUX_SERIAL_MODE:
         g_eeGeneral.auxSerialMode = editChoice(HW_SETTINGS_COLUMN2, y, STR_AUX_SERIAL_MODE, STR_AUX_SERIAL_MODES, g_eeGeneral.auxSerialMode, 0, UART_MODE_MAX, attr, event);
         if (attr && checkIncDec_Ret) {
-          auxSerialInit(g_eeGeneral.auxSerialMode, modelTelemetryProtocol());
+          serialInit(0, g_eeGeneral.auxSerialMode);
         }
         break;
 #endif
diff --git a/radio/src/hal/serial_driver.h b/radio/src/hal/serial_driver.h
index a1aad2263..947225ba5 100644
--- a/radio/src/hal/serial_driver.h
+++ b/radio/src/hal/serial_driver.h
@@ -40,44 +40,45 @@ enum SerialWordLength {
   ETX_WordLength_9,
 };
 
-struct etx_serial_init {
+typedef struct {
   uint32_t baudrate;    // = 0;
   uint8_t parity;       // = ETX_Parity_None;
   uint8_t stop_bits;    // = ETX_StopBits_One;
   uint8_t word_length;  // = ETX_WordLength_8;
   bool rx_enable;       // = false;
 
-  void*    rx_dma_buf;
-  uint32_t rx_dma_buf_len;
-
   void (*on_receive)(uint8_t data);  // = nullptr;
   void (*on_error)();                // = nullptr;
-};
+} etx_serial_init;
 
 struct etx_serial_callbacks_t {
-  bool (*on_send)(uint8_t& data);
+  bool (*on_send)(uint8_t* data);
   void (*on_receive)(uint8_t data);
   void (*on_error)();
 };
 
-struct etx_serial_driver_t {
+typedef struct {
 
-  // Init module communication
-  void (*init)(const etx_serial_init* params);
+  // Init serial communication
+  void* (*init)(const etx_serial_init* params);
 
-  // De-Init module communication
-  void (*deinit)();
+  // De-Init serial communication
+  void (*deinit)(void* ctx);
 
   // Send a single byte
-  void (*sendByte)(uint8_t byte);
+  void (*sendByte)(void* ctx, uint8_t byte);
 
   // Send a buffer
-  void (*sendBuffer)(const uint8_t* data, uint8_t size);
+  void (*sendBuffer)(void* ctx, const uint8_t* data, uint8_t size);
 
   // Wait for last send operation to complete
-  void (*waitForTxCompleted)();
+  void (*waitForTxCompleted)(void* ctx);
 
+  // Fetch byte from internal buffer
+  int (*getByte)(void* ctx, uint8_t* data);
+  
   // Callbacks
-  void (*setReceiveCb)(void (*on_receive)(uint8_t data));
-  void (*setOnErrorCb)(void (*on_error)());
-};
+  void (*setReceiveCb)(void* ctx, void (*on_receive)(uint8_t data));
+  void (*setOnErrorCb)(void* ctx, void (*on_error)());
+
+} etx_serial_driver_t;
diff --git a/radio/src/hal/serial_port.h b/radio/src/hal/serial_port.h
new file mode 100644
index 000000000..25bea20a5
--- /dev/null
+++ b/radio/src/hal/serial_port.h
@@ -0,0 +1,31 @@
+/*
+ * 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 "serial_driver.h"
+
+typedef void etx_pwr_driver;
+
+typedef struct {
+    const etx_serial_driver_t* uart;
+    void (*set_pwr)(uint8_t on);
+} etx_serial_port_t;
diff --git a/radio/src/io/frsky_firmware_update.cpp b/radio/src/io/frsky_firmware_update.cpp
index 5a94ec8ff..1ad1e9cd2 100644
--- a/radio/src/io/frsky_firmware_update.cpp
+++ b/radio/src/io/frsky_firmware_update.cpp
@@ -175,7 +175,7 @@ const uint8_t * FrskyDeviceFirmwareUpdate::readHalfDuplexFrame(uint32_t timeout)
 {
   for (int i = timeout; i >= 0; i--) {
     uint8_t byte ;
-    while (telemetryGetByte(&byte)) {
+    while (sportGetByte(&byte)) {
       if (pushFrskyTelemetryData(byte)) {
         return telemetryRxBuffer;
       }
@@ -251,7 +251,7 @@ void FrskyDeviceFirmwareUpdate::sendFrame()
   switch (module) {
 #if defined(INTERNAL_MODULE_PXX2)
     case INTERNAL_MODULE:
-      IntmoduleSerialDriver.sendBuffer(outputTelemetryBuffer.data,
+      IntmoduleSerialDriver.sendBuffer(uart_ctx, outputTelemetryBuffer.data,
                                        ptr - outputTelemetryBuffer.data);
       return;
 #endif
@@ -316,8 +316,6 @@ static const etx_serial_init serialInitParams = {
   .stop_bits = ETX_StopBits_One,
   .word_length = ETX_WordLength_8,
   .rx_enable = true,
-  .rx_dma_buf = nullptr,
-  .rx_dma_buf_len = 0,
   .on_receive = intmoduleFifoReceive,
   .on_error = intmoduleFifoError,
 };
@@ -354,7 +352,7 @@ const char * FrskyDeviceFirmwareUpdate::doFlashFirmware(const char * filename, P
 
     etx_serial_init params(serialInitParams);
     params.baudrate = 38400;
-    IntmoduleSerialDriver.init(&params);
+    uart_ctx = IntmoduleSerialDriver.init(&params);
 
     GPIO_SetBits(INTMODULE_BOOTCMD_GPIO, INTMODULE_BOOTCMD_GPIO_PIN);
     result = uploadFileToHorusXJT(filename, &file, progressHandler);
@@ -370,7 +368,7 @@ const char * FrskyDeviceFirmwareUpdate::doFlashFirmware(const char * filename, P
     case INTERNAL_MODULE: {
       etx_serial_init params(serialInitParams);
       params.baudrate = 57600;
-      IntmoduleSerialDriver.init(&params);
+      uart_ctx = IntmoduleSerialDriver.init(&params);
     } break;
 #endif
 
@@ -402,14 +400,14 @@ const char * FrskyDeviceFirmwareUpdate::uploadFileToHorusXJT(const char * filena
     return STR_DEVICE_NO_RESPONSE;
   }
 
-  IntmoduleSerialDriver.sendByte(0x81);
+  IntmoduleSerialDriver.sendByte(uart_ctx, 0x81);
   readBuffer(frame, 1, 100);
 
   if (!readBuffer(frame, 8, 100) || frame[0] != 0x02) {
       return STR_DEVICE_NO_RESPONSE;
   }
 
-  IntmoduleSerialDriver.sendByte(0x82);
+  IntmoduleSerialDriver.sendByte(uart_ctx, 0x82);
   readBuffer(frame, 1, 100);
 
   uint8_t index = 0;
@@ -427,7 +425,7 @@ const char * FrskyDeviceFirmwareUpdate::uploadFileToHorusXJT(const char * filena
         return STR_DEVICE_WRONG_REQUEST;
 
     if (count == 0) {
-      IntmoduleSerialDriver.sendByte(0xA1);
+      IntmoduleSerialDriver.sendByte(uart_ctx, 0xA1);
       RTOS_WAIT_MS(50);
       return nullptr;
     }
@@ -435,15 +433,15 @@ const char * FrskyDeviceFirmwareUpdate::uploadFileToHorusXJT(const char * filena
     if (count < 1024)
       memset(((uint8_t *)buffer) + count, 0, 1024 - count);
 
-    IntmoduleSerialDriver.sendByte(frame[0] + 0x80);
-    IntmoduleSerialDriver.sendByte(frame[1]);
+    IntmoduleSerialDriver.sendByte(uart_ctx, frame[0] + 0x80);
+    IntmoduleSerialDriver.sendByte(uart_ctx, frame[1]);
 
     uint16_t crc_16 = crc16(CRC_1189, (uint8_t *)buffer, 1024, crc16(CRC_1189, &frame[1], 1));
     for (size_t i = 0; i < sizeof(buffer); i++) {
-      IntmoduleSerialDriver.sendByte(((uint8_t *)buffer)[i]);
+      IntmoduleSerialDriver.sendByte(uart_ctx, ((uint8_t *)buffer)[i]);
     }
-    IntmoduleSerialDriver.sendByte(crc_16 >> 8);
-    IntmoduleSerialDriver.sendByte(crc_16);
+    IntmoduleSerialDriver.sendByte(uart_ctx, crc_16 >> 8);
+    IntmoduleSerialDriver.sendByte(uart_ctx, crc_16);
 
     index++;
   }
@@ -597,7 +595,7 @@ const char * FrskyChipFirmwareUpdate::waitAnswer(uint8_t & status)
   for (uint8_t i = 0; i < sizeof(buffer); i++) {
     uint32_t retry = 0;
     while (true) {
-      if (telemetryGetByte(&buffer[i])) {
+      if (sportGetByte(&buffer[i])) {
         if ((i == 0 && buffer[0] != 0x7F) ||
             (i == 1 && buffer[1] != 0xFE) ||
             (i == 10 && buffer[10] != 0x0D) ||
diff --git a/radio/src/io/frsky_firmware_update.h b/radio/src/io/frsky_firmware_update.h
index 3763a6a54..5fa129c29 100644
--- a/radio/src/io/frsky_firmware_update.h
+++ b/radio/src/io/frsky_firmware_update.h
@@ -137,6 +137,7 @@ class FrskyDeviceFirmwareUpdate {
     uint32_t address = 0;
     ModuleIndex module;
     uint8_t frame[12];
+    void* uart_ctx = nullptr;
 
     void startFrame(uint8_t command);
     void sendFrame();
diff --git a/radio/src/io/multi_firmware_update.cpp b/radio/src/io/multi_firmware_update.cpp
index 90d8dd9c2..5cff0fdd2 100644
--- a/radio/src/io/multi_firmware_update.cpp
+++ b/radio/src/io/multi_firmware_update.cpp
@@ -28,6 +28,8 @@
 #include "debug.h"
 #include "timers_driver.h"
 
+#include <memory>
+
 #if defined(LIBOPENUI)
   #include "libopenui.h"
 #else
@@ -50,24 +52,26 @@ class MultiFirmwareUpdateDriver
 {
   public:
     MultiFirmwareUpdateDriver() {}
-    const char * flashFirmware(FIL * file, const char * label, ProgressHandler progressHandler) const;
+    virtual ~MultiFirmwareUpdateDriver() {}
+    const char* flashFirmware(FIL* file, const char* label,
+                              ProgressHandler progressHandler);
 
   protected:
     virtual void moduleOn() const = 0;
-    virtual void init(bool inverted) const = 0;
+    virtual void init(bool inverted) = 0;
     virtual bool getByte(uint8_t & byte) const = 0;
     virtual void sendByte(uint8_t byte) const = 0;
     virtual void clear() const = 0;
-    virtual void deinit(bool inverted) const {}
+    virtual void deinit(bool inverted) {}
 
   private:
     bool getRxByte(uint8_t & byte) const;
     bool checkRxByte(uint8_t byte) const;
-    const char * waitForInitialSync(bool& inverted) const;
+    const char * waitForInitialSync(bool& inverted);
     const char * getDeviceSignature(uint8_t * signature) const;
     const char * loadAddress(uint32_t offset) const;
     const char * progPage(uint8_t * buffer, uint16_t size) const;
-    void leaveProgMode(bool inverted) const;
+    void leaveProgMode(bool inverted);
 };
 
 #if defined(INTERNAL_MODULE_MULTI)
@@ -78,8 +82,6 @@ static const etx_serial_init serialInitParams = {
   .stop_bits = ETX_StopBits_One,
   .word_length = ETX_WordLength_8,
   .rx_enable = true,
-  .rx_dma_buf = nullptr,
-  .rx_dma_buf_len = 0,
   .on_receive = intmoduleFifoReceive,
   .on_error = intmoduleFifoError,
 };
@@ -90,16 +92,18 @@ class MultiInternalUpdateDriver: public MultiFirmwareUpdateDriver
     MultiInternalUpdateDriver() {}
 
   protected:
+    void* uart_ctx = nullptr;
+  
     void moduleOn() const override
     {
       INTERNAL_MODULE_ON();
     }
 
-    void init(bool inverted) const override
+    void init(bool inverted) override
     {
       etx_serial_init params(serialInitParams);
       params.baudrate = 57600;
-      IntmoduleSerialDriver.init(&params);
+      uart_ctx = IntmoduleSerialDriver.init(&params);
     }
 
     bool getByte(uint8_t & byte) const override
@@ -109,7 +113,7 @@ class MultiInternalUpdateDriver: public MultiFirmwareUpdateDriver
 
     void sendByte(uint8_t byte) const override
     {
-      IntmoduleSerialDriver.sendByte(byte);
+      IntmoduleSerialDriver.sendByte(uart_ctx, byte);
     }
 
     void clear() const override
@@ -117,13 +121,13 @@ class MultiInternalUpdateDriver: public MultiFirmwareUpdateDriver
       intmoduleFifo.clear();
     }
 
-    void deinit(bool inverted) const override
+    void deinit(bool inverted) override
     {
+      IntmoduleSerialDriver.deinit(uart_ctx);
+      uart_ctx = nullptr;
       clear();
     }
 };
-
-static const MultiInternalUpdateDriver multiInternalUpdateDriver;
 #endif
 
 class MultiExternalUpdateDriver: public MultiFirmwareUpdateDriver
@@ -137,7 +141,7 @@ class MultiExternalUpdateDriver: public MultiFirmwareUpdateDriver
       EXTERNAL_MODULE_ON();
     }
 
-    void init(bool inverted) const override
+    void init(bool inverted) override
     {
 #if !defined(EXTMODULE_USART)
       GPIO_InitTypeDef GPIO_InitStructure;
@@ -157,7 +161,7 @@ class MultiExternalUpdateDriver: public MultiFirmwareUpdateDriver
 
     bool getByte(uint8_t & byte) const override
     {
-      return telemetryGetByte(&byte);
+      return sportGetByte(&byte);
     }
 
     void sendByte(uint8_t byte) const override
@@ -172,7 +176,7 @@ class MultiExternalUpdateDriver: public MultiFirmwareUpdateDriver
       telemetryClearFifo();
     }
 
-    void deinit(bool inverted) const override
+    void deinit(bool inverted) override
     {
       if (inverted)
         telemetryPortInvertedInit(0);
@@ -183,8 +187,6 @@ class MultiExternalUpdateDriver: public MultiFirmwareUpdateDriver
     }
 };
 
-static const MultiExternalUpdateDriver multiExternalUpdateDriver;
-
 class MultiExtSportUpdateDriver: public MultiFirmwareUpdateDriver
 {
   public:
@@ -196,14 +198,14 @@ class MultiExtSportUpdateDriver: public MultiFirmwareUpdateDriver
       EXTERNAL_MODULE_ON();
     }
 
-    void init(bool inverted) const override
+    void init(bool inverted) override
     {
       telemetryPortInit(57600, TELEMETRY_SERIAL_WITHOUT_DMA);
     }
 
     bool getByte(uint8_t & byte) const override
     {
-      return telemetryGetByte(&byte);
+      return sportGetByte(&byte);
     }
 
     void sendByte(uint8_t byte) const override
@@ -217,15 +219,13 @@ class MultiExtSportUpdateDriver: public MultiFirmwareUpdateDriver
       telemetryClearFifo();
     }
 
-    void deinit(bool inverted) const override
+    void deinit(bool inverted) override
     {
       telemetryPortInit(0, 0);
       clear();
     }
 };
 
-static const MultiExtSportUpdateDriver multiExtSportUpdateDriver;
-
 bool MultiFirmwareUpdateDriver::getRxByte(uint8_t & byte) const
 {
   uint16_t time;
@@ -251,7 +251,7 @@ bool MultiFirmwareUpdateDriver::checkRxByte(uint8_t byte) const
   return getRxByte(rxchar) ? rxchar == byte : false;
 }
 
-const char * MultiFirmwareUpdateDriver::waitForInitialSync(bool & inverted) const
+const char * MultiFirmwareUpdateDriver::waitForInitialSync(bool & inverted)
 {
   uint8_t byte;
   int retries = 200;
@@ -375,7 +375,7 @@ const char * MultiFirmwareUpdateDriver::progPage(uint8_t * buffer, uint16_t size
   return nullptr;
 }
 
-void MultiFirmwareUpdateDriver::leaveProgMode(bool inverted) const
+void MultiFirmwareUpdateDriver::leaveProgMode(bool inverted)
 {
   sendByte(STK_LEAVE_PROGMODE);
   sendByte(CRC_EOP);
@@ -385,7 +385,8 @@ void MultiFirmwareUpdateDriver::leaveProgMode(bool inverted) const
   deinit(inverted);
 }
 
-const char * MultiFirmwareUpdateDriver::flashFirmware(FIL * file, const char * label, ProgressHandler progressHandler) const
+const char* MultiFirmwareUpdateDriver::flashFirmware(
+    FIL* file, const char* label, ProgressHandler progressHandler)
 {
 #if defined(SIMU)
   for (uint16_t i = 0; i < 100; i++) {
@@ -616,13 +617,15 @@ bool MultiDeviceFirmwareUpdate::flashFirmware(const char * filename, ProgressHan
     }
   }
 
-  const MultiFirmwareUpdateDriver * driver = &multiExternalUpdateDriver;
+  std::unique_ptr<MultiFirmwareUpdateDriver> driver;
+  if (module == EXTERNAL_MODULE)
+    driver.reset(new MultiExternalUpdateDriver());
 #if defined(INTERNAL_MODULE_MULTI)
-  if (module == INTERNAL_MODULE)
-    driver = &multiInternalUpdateDriver;
+  else if (module == INTERNAL_MODULE)
+    driver.reset(new MultiInternalUpdateDriver());
 #endif
-  if (type == MULTI_TYPE_ELRS)
-    driver = &multiExtSportUpdateDriver;
+  else if (type == MULTI_TYPE_ELRS)
+    driver.reset(new MultiExtSportUpdateDriver());
 
   pausePulses();
 
diff --git a/radio/src/lua/api_general.cpp b/radio/src/lua/api_general.cpp
index e25ceee99..5d92ed46e 100644
--- a/radio/src/lua/api_general.cpp
+++ b/radio/src/lua/api_general.cpp
@@ -91,9 +91,49 @@
   { "EVT_"#xxx"_LONG", EVT_KEY_LONG(yyy) }, \
   { "EVT_"#xxx"_REPT", EVT_KEY_REPT(yyy) }
 
-#if defined(LUA) && !defined(CLI)
-Fifo<uint8_t, LUA_FIFO_SIZE> * luaRxFifo = nullptr;
-#endif
+// Note:
+// - luaRxFifo & luaReceiveData are used only for USB serial
+// - otherwise, the AUX serial buffer is used directly
+//
+static Fifo<uint8_t, LUA_FIFO_SIZE>* luaRxFifo = nullptr;
+
+static int luaRxFifoGetByte(void*, uint8_t* data)
+{
+  if (!luaRxFifo) return -1;
+  return luaRxFifo->pop(*data);
+}
+
+void luaReceiveData(uint8_t* buf, uint32_t len)
+{
+  if (!luaRxFifo) {
+    luaRxFifo = new Fifo<uint8_t, LUA_FIFO_SIZE>();
+    luaSetGetSerialByte(nullptr, luaRxFifoGetByte);
+  }
+    
+  if (luaRxFifo) {
+    while(len--) luaRxFifo->push(*buf++);
+  }
+}
+
+static void (*luaSendDataCb)(void*, uint8_t) = nullptr;
+static void* luaSendDataCtx = nullptr;
+
+void luaSetSendCb(void* ctx, void (*cb)(void*, uint8_t))
+{
+  luaSendDataCb = nullptr;
+  luaSendDataCtx = ctx;
+  luaSendDataCb = cb;
+}
+
+static int (*luaGetSerialByte)(void*, uint8_t*) = nullptr;
+static void* luaGetSerialByteCtx = nullptr;
+
+void luaSetGetSerialByte(void* ctx, int (*fct)(void*, uint8_t*))
+{
+  luaGetSerialByte = nullptr;
+  luaGetSerialByteCtx = ctx;
+  luaGetSerialByte = fct;
+}
 
 /*luadoc
 @function getVersion()
@@ -1882,22 +1922,23 @@ Set baudrate for serial port(s) affected to LUA
 */
 static int luaSetSerialBaudrate(lua_State * L)
 {
-#if defined(AUX_SERIAL) || defined(AUX2_SERIAL)
-  unsigned int baudrate = luaL_checkunsigned(L, 1);
-#endif
+// #if defined(AUX_SERIAL) || defined(AUX2_SERIAL)
+//   unsigned int baudrate = luaL_checkunsigned(L, 1);
+// #endif
 
-#if defined(AUX_SERIAL)
-  if (auxSerialMode == UART_MODE_LUA) {
-    auxSerialStop();
-    auxSerialSetup(baudrate, false);
-  }
-#endif
-#if defined(AUX2_SERIAL)
-  if (aux2SerialMode == UART_MODE_LUA) {
-    aux2SerialStop();
-    aux2SerialSetup(baudrate, false);
-  }
-#endif
+// TODO: add some callbacks for serial settings
+// #if defined(AUX_SERIAL)
+//   if (auxSerialMode == UART_MODE_LUA) {
+//     auxSerialStop();
+//     auxSerialSetup(baudrate, false);
+//   }
+// #endif
+// #if defined(AUX2_SERIAL)
+//   if (aux2SerialMode == UART_MODE_LUA) {
+//     aux2SerialStop();
+//     aux2SerialSetup(baudrate, false);
+//   }
+// #endif
   return 1;
 }
 
@@ -1917,30 +1958,15 @@ static int luaSerialWrite(lua_State * L)
   if (!str || len < 1)
     return 0;
 
-#if defined(USB_SERIAL)
-  if (getSelectedUsbMode() == USB_SERIAL_MODE) {
+  auto _sendCb = luaSendDataCb;
+  auto _ctx = luaSendDataCtx;
+
+  if (_sendCb) {
     size_t wr_len = len;
     const char* p = str;
-    while(wr_len--) usbSerialPutc(*p++);
+    while(wr_len--) _sendCb(_ctx, *p++);
   }
-#endif
-
-#if defined(AUX_SERIAL)
-  if (auxSerialMode == UART_MODE_LUA) {
-    size_t wr_len = len;
-    const char* p = str;
-    while(wr_len--) auxSerialPutc(*p++);
-  }
-#endif
-
-#if defined(AUX2_SERIAL)
-  if (aux2SerialMode == UART_MODE_LUA) {
-    size_t wr_len = len;
-    const char* p = str;
-    while(wr_len--) aux2SerialPutc(*p++);
-  }
-#endif
-
+  
   return 0;
 }
 
@@ -1962,34 +1988,29 @@ static int luaSerialRead(lua_State * L)
 #if defined(LUA) && !defined(CLI)
   int num = luaL_optunsigned(L, 1, 0);
 
-  if (!luaRxFifo) {
-    // TODO:
-    // - check which serial port has been assigned this function
-    // - set the receive callback on that serial port
-    //
-    luaRxFifo = new Fifo<uint8_t, LUA_FIFO_SIZE>();
-    if (!luaRxFifo) {
-      lua_pushlstring(L, "", 0);
-      return 1;
-    }
-  }
   uint8_t str[LUA_FIFO_SIZE];
   uint8_t *p = str;
-  while (luaRxFifo->pop(*p)) {
-    p++;  // increment only when pop was successful
-    if (p - str >= LUA_FIFO_SIZE) {
-      // buffer full
-      break;
-    }
-    if (num == 0) {
-      if (*(p - 1) == '\n' || *(p - 1) == '\r') {
-        // found newline
+
+  auto _getByte = luaGetSerialByte;
+  auto _ctx = luaGetSerialByteCtx;
+
+  if (_getByte) {
+    while (_getByte(_ctx, p) > 0) {
+      p++;  // increment only when pop was successful
+      if (p - str >= LUA_FIFO_SIZE) {
+        // buffer full
+        break;
+      }
+      if (num == 0) {
+        if (*(p - 1) == '\n' || *(p - 1) == '\r') {
+          // found newline
+          break;
+        }
+      }
+      else if (p - str >= num) {
+        // requested number of characters reached
         break;
       }
-    }
-    else if (p - str >= num) {
-      // requested number of characters reached
-      break;
     }
   }
   lua_pushlstring(L, (const char*)str, p - str);
diff --git a/radio/src/lua/lua_api.h b/radio/src/lua/lua_api.h
index 28a88aa7a..4506c4b2f 100644
--- a/radio/src/lua/lua_api.h
+++ b/radio/src/lua/lua_api.h
@@ -48,10 +48,11 @@ extern "C" {
   #endif
 #endif
 
-#if !defined(CLI) || defined(AUX2_SERIAL)
+// LUA serial connection
 #define LUA_FIFO_SIZE 256
-extern Fifo<uint8_t, LUA_FIFO_SIZE> * luaRxFifo;
-#endif
+void luaReceiveData(uint8_t* buf, uint32_t len);
+void luaSetSendCb(void* ctx, void (*cb)(void*, uint8_t));
+void luaSetGetSerialByte(void* ctx, int (*fct)(void*, uint8_t*));
 
 extern lua_State * lsScripts;
 
diff --git a/radio/src/main.cpp b/radio/src/main.cpp
index fda115218..b562d58c7 100644
--- a/radio/src/main.cpp
+++ b/radio/src/main.cpp
@@ -26,6 +26,10 @@
   #include "libopenui.h"
 #endif
 
+#if defined(CLI)
+  #include "cli.h"
+#endif
+
 uint8_t currentSpeakerVolume = 255;
 uint8_t requiredSpeakerVolume = 255;
 uint8_t currentBacklightBright = 0;
@@ -153,6 +157,22 @@ void handleUsbConnection()
         opentxClose(false);
         usbPluggedIn();
       }
+#if defined(USB_SERIAL)
+      else if (getSelectedUsbMode() == USB_SERIAL_MODE) {
+        // TODO: query USB serial mode
+        //  -> for now, only CLI / DEBUG / LUA
+#if defined(CLI)
+        cliSetSendCb(nullptr, usbSerialPutc);
+        usbSerialSetReceiveDataCb(cliReceiveData);
+#elif defined(DEBUG)
+        dbgSerialSetSendCb(nullptr, usbSerialPutc);
+        usbSerialSetReceiveDataCb(nullptr);
+#elif defined(LUA)
+        luaSetSendCb(nullptr, usbSerialPutc);
+        usbSerialSetReceiveDataCb(luaReceiveData);
+#endif
+      }
+#endif
 
       usbStart();
       TRACE("USB started");
diff --git a/radio/src/opentx.cpp b/radio/src/opentx.cpp
index fdf5d543b..987dad94c 100644
--- a/radio/src/opentx.cpp
+++ b/radio/src/opentx.cpp
@@ -1869,14 +1869,8 @@ void opentxInit()
 #endif
 #endif  // #if !defined(EEPROM)
 
-#if defined(AUX_SERIAL)
-  auxSerialInit(g_eeGeneral.auxSerialMode, modelTelemetryProtocol());
-#endif
-
-#if defined(AUX2_SERIAL)
-  aux2SerialInit(g_eeGeneral.aux2SerialMode, modelTelemetryProtocol());
-#endif
-
+  initSerialPorts();
+  
   currentSpeakerVolume = requiredSpeakerVolume = g_eeGeneral.speakerVolume + VOLUME_LEVEL_DEF;
   currentBacklightBright = requiredBacklightBright = g_eeGeneral.backlightBright;
 #if !defined(SOFTWARE_VOLUME)
diff --git a/radio/src/pulses/afhds2.cpp b/radio/src/pulses/afhds2.cpp
index 93b1bebdf..b8be70990 100644
--- a/radio/src/pulses/afhds2.cpp
+++ b/radio/src/pulses/afhds2.cpp
@@ -45,8 +45,6 @@ const etx_serial_init afhds2SerialInitParams = {
     .stop_bits = ETX_StopBits_One,
     .word_length = ETX_WordLength_8,
     .rx_enable = true,
-    .rx_dma_buf = nullptr,
-    .rx_dma_buf_len = 0,
     .on_receive = intmoduleFifoReceive,
     .on_error = intmoduleFifoError,
 };
@@ -69,11 +67,9 @@ static void* afhds2Init(uint8_t module)
 
 static void afhds2DeInit(void* context)
 {
-  (void)context;
-
   INTERNAL_MODULE_OFF();
   intmoduleFifo.clear();
-  IntmoduleSerialDriver.deinit();
+  IntmoduleSerialDriver.deinit(context);
 
   // mixer setup
   mixerSchedulerSetPeriod(INTERNAL_MODULE, 0);
@@ -97,11 +93,9 @@ static void afhds2SetupPulses(void* context, int16_t* channels, uint8_t nChannel
 
 static void afhds2SendPulses(void* context)
 {
-  (void)context;
-
   uint8_t* data = (uint8_t*)intmodulePulsesData.flysky.pulses;
   uint16_t size = intmodulePulsesData.flysky.ptr - data;
-  IntmoduleSerialDriver.sendBuffer(data, size);
+  IntmoduleSerialDriver.sendBuffer(context, data, size);
 }
 
 const etx_module_driver_t Afhds2InternalDriver = {
diff --git a/radio/src/pulses/crossfire.cpp b/radio/src/pulses/crossfire.cpp
index a176e8ccd..5d1e9df4d 100644
--- a/radio/src/pulses/crossfire.cpp
+++ b/radio/src/pulses/crossfire.cpp
@@ -134,8 +134,6 @@ static const etx_serial_init intmoduleCrossfireInitParams = {
   .stop_bits = ETX_StopBits_One,
   .word_length = ETX_WordLength_8,
   .rx_enable = true,
-  .rx_dma_buf = nullptr,
-  .rx_dma_buf_len = 0,
   .on_receive = intmoduleCRSF_rx,
   .on_error = nullptr,
 };
@@ -177,9 +175,7 @@ static void crossfireSetupPulsesInternal(void* context, int16_t* channels, uint8
 
 static void crossfireSendPulsesInternal(void* context)
 {
-  (void)context;
-
-  IntmoduleSerialDriver.sendBuffer(intmodulePulsesData.crossfire.pulses,
+  IntmoduleSerialDriver.sendBuffer(context, intmodulePulsesData.crossfire.pulses,
                                    intmodulePulsesData.crossfire.length);
 }
 
diff --git a/radio/src/pulses/multi.cpp b/radio/src/pulses/multi.cpp
index d1190be5a..ff75960d4 100644
--- a/radio/src/pulses/multi.cpp
+++ b/radio/src/pulses/multi.cpp
@@ -60,8 +60,6 @@ etx_serial_init multiSerialInitParams = {
     .stop_bits = ETX_StopBits_Two,
     .word_length = ETX_WordLength_9,
     .rx_enable = true,
-    .rx_dma_buf = nullptr,
-    .rx_dma_buf_len = 0,
     .on_receive = intmoduleFifoReceive,
     .on_error = intmoduleFifoError,
 };
@@ -260,7 +258,7 @@ static void* multiInit(uint8_t module)
   // serial port setup
   intmodulePulsesData.multi.initFrame();
   intmoduleFifo.clear();
-  IntmoduleSerialDriver.init(&multiSerialInitParams);
+  void* uart_ctx = IntmoduleSerialDriver.init(&multiSerialInitParams);
 
   // mixer setup
   mixerSchedulerSetPeriod(INTERNAL_MODULE, MULTIMODULE_PERIOD);
@@ -276,16 +274,14 @@ static void* multiInit(uint8_t module)
   TRACE("counter = %d", moduleState[INTERNAL_MODULE].counter);
 #endif
 
-  return nullptr;
+  return uart_ctx;
 }
 
 static void multiDeInit(void* context)
 {
-  (void)context;
-
   INTERNAL_MODULE_OFF();
   mixerSchedulerSetPeriod(INTERNAL_MODULE, 0);
-  IntmoduleSerialDriver.deinit();
+  IntmoduleSerialDriver.deinit(context);
 }
 
 static void multiSetupPulses(void* context, int16_t* channels, uint8_t nChannels)
@@ -301,8 +297,7 @@ static void multiSetupPulses(void* context, int16_t* channels, uint8_t nChannels
 
 static void multiSendPulses(void* context)
 {
-  (void)context;
-  IntmoduleSerialDriver.sendBuffer(intmodulePulsesData.multi.getData(),
+  IntmoduleSerialDriver.sendBuffer(context, intmodulePulsesData.multi.getData(),
                                    intmodulePulsesData.multi.getSize());
 }
 
diff --git a/radio/src/pulses/pulses.cpp b/radio/src/pulses/pulses.cpp
index c1732939a..4cd50f240 100755
--- a/radio/src/pulses/pulses.cpp
+++ b/radio/src/pulses/pulses.cpp
@@ -476,8 +476,8 @@ void enablePulsesExternalModule(uint8_t protocol)
 
 #if defined(PXX1) && defined(HARDWARE_EXTERNAL_MODULE_SIZE_SML)
     case PROTOCOL_CHANNELS_PXX1_SERIAL:
-      extmodulePxx1SerialStart();
-      mixerSchedulerSetPeriod(EXTERNAL_MODULE, EXTMODULE_PXX1_SERIAL_PERIOD);
+      externalModuleContext = Pxx1ExternalSerialDriver.init(EXTERNAL_MODULE);
+      externalModuleDriver = &Pxx1ExternalSerialDriver;
       break;
 #endif
 
@@ -522,12 +522,8 @@ void enablePulsesExternalModule(uint8_t protocol)
 
 #if defined(MULTIMODULE)
     case PROTOCOL_CHANNELS_MULTIMODULE:
-#if defined(PCBSKY9X)
-      extmoduleSerialStart(MULTIMODULE_BAUDRATE, MULTIMODULE_PERIOD * 2000, true);
-#else
       extmoduleSerialStart();
       mixerSchedulerSetPeriod(EXTERNAL_MODULE, MULTIMODULE_PERIOD);
-#endif
       getMultiModuleStatus(EXTERNAL_MODULE).failsafeChecked = false;
       getMultiModuleStatus(EXTERNAL_MODULE).flags = 0;
 #if defined(MULTI_PROTOLIST)
@@ -558,6 +554,7 @@ void enablePulsesExternalModule(uint8_t protocol)
 
 #if defined(AFHDS3)
     case PROTOCOL_CHANNELS_AFHDS3:
+      // convert to serial module interface
       extmodulePulsesData.afhds3.init(EXTERNAL_MODULE);
       extmoduleSerialStart();
       mixerSchedulerSetPeriod(EXTERNAL_MODULE, AFHDS3_COMMAND_TIMEOUT * 1000 /* us */);
@@ -591,12 +588,6 @@ bool setupPulsesExternalModule(uint8_t protocol)
       return true;
 #endif
 
-#if defined(PXX1) && defined(HARDWARE_EXTERNAL_MODULE_SIZE_SML)
-    case PROTOCOL_CHANNELS_PXX1_SERIAL:
-      extmodulePulsesData.pxx_uart.setupFrame(EXTERNAL_MODULE);
-      return true;
-#endif
-
 #if defined(SBUS)
     case PROTOCOL_CHANNELS_SBUS:
       setupPulsesSbus();
@@ -681,13 +672,6 @@ void extmoduleSendNextFrame()
       break;
 #endif
 
-#if defined(PXX1) && defined(HARDWARE_EXTERNAL_MODULE_SIZE_SML)
-    case PROTOCOL_CHANNELS_PXX1_SERIAL:
-      ExtmoduleSerialDriver.sendBuffer(extmodulePulsesData.pxx_uart.getData(),
-                                       extmodulePulsesData.pxx_uart.getSize());
-      break;
-#endif
-
 #if defined(AFHDS3)
     case PROTOCOL_CHANNELS_AFHDS3:
 #if defined(EXTMODULE_USART) && defined(EXTMODULE_TX_INVERT_GPIO)
diff --git a/radio/src/pulses/pxx1.cpp b/radio/src/pulses/pxx1.cpp
index bb592760b..833cb53b2 100644
--- a/radio/src/pulses/pxx1.cpp
+++ b/radio/src/pulses/pxx1.cpp
@@ -231,17 +231,13 @@ static const etx_serial_init pxx1SerialInit = {
   .stop_bits = ETX_StopBits_One,
   .word_length = ETX_WordLength_8,
   .rx_enable = false,
-  .rx_dma_buf = nullptr,
-  .rx_dma_buf_len = 0,
   .on_receive = intmoduleFifoReceive,
   .on_error = intmoduleFifoError,
 };
 
 static void* pxx1InitInternal(uint8_t module)
 {
-  (void)module;
-
-  IntmoduleSerialDriver.init(&pxx1SerialInit);
+  void* uart_ctx = IntmoduleSerialDriver.init(&pxx1SerialInit);
 
 #if defined(INTMODULE_HEARTBEAT)
   init_intmodule_heartbeat();
@@ -249,19 +245,17 @@ static void* pxx1InitInternal(uint8_t module)
   mixerSchedulerSetPeriod(INTERNAL_MODULE, INTMODULE_PXX1_SERIAL_PERIOD);
   INTERNAL_MODULE_ON();
 
-  return nullptr;
+  return uart_ctx;
 }
 
 static void pxx1DeInitInternal(void* context)
 {
-  (void)context;
-
   INTERNAL_MODULE_OFF();
   mixerSchedulerSetPeriod(INTERNAL_MODULE, 0);
 #if defined(INTMODULE_HEARTBEAT)
   stop_intmodule_heartbeat();
 #endif
-  IntmoduleSerialDriver.deinit();
+  IntmoduleSerialDriver.deinit(context);
 }
 
 static void pxx1SetupPulsesInternal(void* context, int16_t* channels, uint8_t nChannels)
@@ -276,8 +270,7 @@ static void pxx1SetupPulsesInternal(void* context, int16_t* channels, uint8_t nC
 
 static void pxx1SendPulsesInternal(void* context)
 {
-  (void)context;
-  IntmoduleSerialDriver.sendBuffer(intmodulePulsesData.pxx_uart.getData(),
+  IntmoduleSerialDriver.sendBuffer(context, intmodulePulsesData.pxx_uart.getData(),
                                    intmodulePulsesData.pxx_uart.getSize());
 }
 
@@ -290,3 +283,60 @@ const etx_module_driver_t Pxx1InternalSerialDriver = {
 };
 
 #endif
+
+#if defined(EXTMODULE_USART) && defined(HARDWARE_EXTERNAL_MODULE_SIZE_SML)
+#include "extmodule_serial_driver.h"
+
+static const etx_serial_init pxx1ExtSerialInit = {
+  .baudrate = EXTMODULE_PXX1_SERIAL_BAUDRATE,
+  .parity = ETX_Parity_None,
+  .stop_bits = ETX_StopBits_One,
+  .word_length = ETX_WordLength_8,
+  .rx_enable = false,
+  .on_receive = extmoduleFifoReceive,
+  .on_error = extmoduleFifoError,
+};
+
+static void* pxx1InitExternal(uint8_t module)
+{
+  void* uart_ctx = ExtmoduleSerialDriver.init(&pxx1ExtSerialInit);
+
+  mixerSchedulerSetPeriod(EXTERNAL_MODULE, EXTMODULE_PXX1_SERIAL_PERIOD);
+  EXTERNAL_MODULE_ON();
+
+  return uart_ctx;
+}
+
+static void pxx1DeInitExternal(void* context)
+{
+  EXTERNAL_MODULE_OFF();
+  mixerSchedulerSetPeriod(EXTERNAL_MODULE, 0);
+  ExtmoduleSerialDriver.deinit(context);
+}
+
+static void pxx1SetupPulsesExternal(void* context, int16_t* channels, uint8_t nChannels)
+{
+  (void)context;
+
+  // TODO:
+  (void)channels;
+  (void)nChannels;
+
+  extmodulePulsesData.pxx_uart.setupFrame(EXTERNAL_MODULE);
+}
+
+static void pxx1SendPulsesExternal(void* context)
+{
+  ExtmoduleSerialDriver.sendBuffer(context, extmodulePulsesData.pxx_uart.getData(),
+                                   extmodulePulsesData.pxx_uart.getSize());
+}
+
+const etx_module_driver_t Pxx1ExternalSerialDriver = {
+  .protocol = PROTOCOL_CHANNELS_PXX1_SERIAL,
+  .init = pxx1InitExternal,
+  .deinit = pxx1DeInitExternal,
+  .setupPulses = pxx1SetupPulsesExternal,
+  .sendPulses = pxx1SendPulsesExternal,
+};
+
+#endif
diff --git a/radio/src/pulses/pxx1.h b/radio/src/pulses/pxx1.h
index 40d219d55..84b1259c6 100644
--- a/radio/src/pulses/pxx1.h
+++ b/radio/src/pulses/pxx1.h
@@ -168,6 +168,12 @@ typedef Pxx1Pulses<UartPxx1Transport> UartPxx1Pulses;
 typedef Pxx1Pulses<StandardPxx1Transport<PwmPxxBitTransport>> PwmPxx1Pulses;
 typedef Pxx1Pulses<StandardPxx1Transport<SerialPxxBitTransport>> SerialPxx1Pulses;
 
+#if defined(INTMODULE_USART)
 extern const etx_module_driver_t Pxx1InternalSerialDriver;
+#endif
+
+#if defined(EXTMODULE_USART)
+extern const etx_module_driver_t Pxx1ExternalSerialDriver;
+#endif
 
 #endif
diff --git a/radio/src/pulses/pxx2.cpp b/radio/src/pulses/pxx2.cpp
index bab20cb05..6fe768266 100644
--- a/radio/src/pulses/pxx2.cpp
+++ b/radio/src/pulses/pxx2.cpp
@@ -36,8 +36,6 @@ const etx_serial_init pxx2SerialInitParams = {
     .stop_bits = ETX_StopBits_One,
     .word_length = ETX_WordLength_8,
     .rx_enable = true,
-    .rx_dma_buf = nullptr,
-    .rx_dma_buf_len = 0,
     .on_receive = intmoduleFifoReceive,
     .on_error = intmoduleFifoError,
 };
@@ -652,7 +650,7 @@ void Pxx2OtaUpdate::flashFirmware(const char * filename, ProgressHandler progres
 static void* pxx2InitInternal(uint8_t moduleType)
 {
   intmoduleFifo.clear();
-  IntmoduleSerialDriver.init(&pxx2SerialInitParams);
+  void* uart_ctx = IntmoduleSerialDriver.init(&pxx2SerialInitParams);
   resetAccessAuthenticationCount();
 
 #if defined(INTMODULE_HEARTBEAT)
@@ -662,13 +660,13 @@ static void* pxx2InitInternal(uint8_t moduleType)
   mixerSchedulerSetPeriod(INTERNAL_MODULE, PXX2_PERIOD);
   INTERNAL_MODULE_ON();
 
-  return nullptr;
+  return uart_ctx;
 }
 
 static void pxx2DeInitInternal(void* context)
 {
   INTERNAL_MODULE_OFF();
-  IntmoduleSerialDriver.deinit();
+  IntmoduleSerialDriver.deinit(context);
 #if defined(INTMODULE_HEARTBEAT)
   stop_intmodule_heartbeat();
 #endif
@@ -694,10 +692,8 @@ static void pxx2SetupPulsesInternal(void* context, int16_t* channels, uint8_t nC
 
 static void pxx2SendPulsesInternal(void* context)
 {
-  (void)context;
-
   if (pxx2InternalSendNextFrame) {
-    IntmoduleSerialDriver.sendBuffer(intmodulePulsesData.pxx2.getData(),
+    IntmoduleSerialDriver.sendBuffer(context, intmodulePulsesData.pxx2.getData(),
                                      intmodulePulsesData.pxx2.getSize());
   }
 }
@@ -721,8 +717,6 @@ static const etx_serial_init pxx2ExtSerialInitParams = {
   .stop_bits = ETX_StopBits_One,
   .word_length = ETX_WordLength_8,
   .rx_enable = true,
-  .rx_dma_buf = nullptr,
-  .rx_dma_buf_len = 0,
   .on_receive = extmoduleFifoReceive,
   .on_error = extmoduleFifoError,
 };
@@ -743,21 +737,19 @@ static void* pxx2InitExternal(uint8_t module)
 {
   etx_serial_init params(pxx2ExtSerialInitParams);
   params.baudrate = PXX2_HIGHSPEED_BAUDRATE;
-  ExtmoduleSerialDriver.init(&params);
+  void* uart_ctx = ExtmoduleSerialDriver.init(&params);
 
   mixerSchedulerSetPeriod(EXTERNAL_MODULE, PXX2_NO_HEARTBEAT_PERIOD);
   EXTERNAL_MODULE_ON();
 
-  return nullptr;
+  return uart_ctx;
 }
 
 static void pxx2DeInitExternal(void* context)
 {
-  (void)context;
-
   EXTERNAL_MODULE_OFF();
   mixerSchedulerSetPeriod(EXTERNAL_MODULE, 0);
-  ExtmoduleSerialDriver.deinit();
+  ExtmoduleSerialDriver.deinit(context);
 }
 
 static void pxx2SetupPulsesExternal(void* context, int16_t* channels, uint8_t nChannels)
@@ -768,8 +760,7 @@ static void pxx2SetupPulsesExternal(void* context, int16_t* channels, uint8_t nC
 
 static void pxx2SendPulsesExternal(void* context)
 {
-  (void)context;
-  ExtmoduleSerialDriver.sendBuffer(extmodulePulsesData.pxx2.getData(),
+  ExtmoduleSerialDriver.sendBuffer(context, extmodulePulsesData.pxx2.getData(),
                                    extmodulePulsesData.pxx2.getSize());
 }
 
diff --git a/radio/src/sbus.cpp b/radio/src/sbus.cpp
index 8ed40d1c0..1c61f9b74 100644
--- a/radio/src/sbus.cpp
+++ b/radio/src/sbus.cpp
@@ -36,14 +36,45 @@
 
 #define SBUS_CH_CENTER         0x3E0
 
+static int (*_sbusAuxGetByte)(void*, uint8_t*) = nullptr;
+static void* _sbusAuxGetByteCtx = nullptr;
+
+void sbusSetAuxGetByte(void* ctx, int (*fct)(void*, uint8_t*))
+{
+  _sbusAuxGetByte = nullptr;
+  _sbusAuxGetByteCtx = ctx;
+  _sbusAuxGetByte = fct;
+}
+
+int sbusAuxGetByte(uint8_t* byte)
+{
+  auto _getByte = _sbusAuxGetByte;
+  auto _ctx = _sbusAuxGetByteCtx;
+
+  if (_getByte) {
+    return _getByte(_ctx, byte);
+  }
+
+  return -1;
+}
+
+static int (*sbusGetByte)(uint8_t*) = nullptr;
+
+void sbusSetGetByte(int (*fct)(uint8_t*))
+{
+  sbusGetByte = fct;
+}
+
 // Range for pulses (ppm input) is [-512:+512]
 void processSbusFrame(uint8_t * sbus, int16_t * pulses, uint32_t size)
 {
-  if (size != SBUS_FRAME_SIZE || sbus[0] != SBUS_START_BYTE || sbus[SBUS_FRAME_SIZE-1] != SBUS_END_BYTE) {
-    return; // not a valid SBUS frame
+  if (size != SBUS_FRAME_SIZE || sbus[0] != SBUS_START_BYTE ||
+      sbus[SBUS_FRAME_SIZE - 1] != SBUS_END_BYTE) {
+    return;  // not a valid SBUS frame
   }
-  if ((sbus[SBUS_FLAGS_IDX] & (1<<SBUS_FAILSAFE_BIT)) || (sbus[SBUS_FLAGS_IDX] & (1<<SBUS_FRAMELOST_BIT))) {
-    return; // SBUS invalid frame or failsafe mode
+  if ((sbus[SBUS_FLAGS_IDX] & (1 << SBUS_FAILSAFE_BIT)) ||
+      (sbus[SBUS_FLAGS_IDX] & (1 << SBUS_FRAMELOST_BIT))) {
+    return;  // SBUS invalid frame or failsafe mode
   }
 
   sbus++; // skip start byte
@@ -65,31 +96,29 @@ void processSbusFrame(uint8_t * sbus, int16_t * pulses, uint32_t size)
 
 void processSbusInput()
 {
-#if !defined(SIMU)
   uint8_t rxchar;
   uint32_t active = 0;
   static uint8_t SbusIndex = 0;
   static uint16_t SbusTimer;
   static uint8_t SbusFrame[SBUS_FRAME_SIZE];
 
-  while (sbusGetByte(&rxchar)) {
+  auto _getByte = sbusGetByte;
+  while (_getByte && (_getByte(&rxchar) > 0)) {
     active = 1;
-    if (SbusIndex > SBUS_FRAME_SIZE-1) {
-      SbusIndex = SBUS_FRAME_SIZE-1;
+    if (SbusIndex > SBUS_FRAME_SIZE - 1) {
+      SbusIndex = SBUS_FRAME_SIZE - 1;
     }
     SbusFrame[SbusIndex++] = rxchar;
   }
   if (active) {
     SbusTimer = getTmr2MHz();
     return;
-  }
-  else {
+  } else {
     if (SbusIndex) {
-      if ((uint16_t) (getTmr2MHz() - SbusTimer) > SBUS_FRAME_GAP_DELAY) {
+      if ((uint16_t)(getTmr2MHz() - SbusTimer) > SBUS_FRAME_GAP_DELAY) {
         processSbusFrame(SbusFrame, ppmInput, SbusIndex);
         SbusIndex = 0;
       }
     }
   }
-#endif
 }
diff --git a/radio/src/sbus.h b/radio/src/sbus.h
index f6a1b4579..981a7c7ed 100644
--- a/radio/src/sbus.h
+++ b/radio/src/sbus.h
@@ -25,6 +25,17 @@
 #define SBUS_BAUDRATE         100000
 #define SBUS_FRAME_SIZE       25
 
+// Setup SBUS AUX serial input
+void sbusSetAuxGetByte(void* ctx, int (*fct)(void*, uint8_t*));
+
+// SBUS AUX serial getter:
+//  if set, it will fetch data from the handler set
+//  with sbusSetAuxGetByte()
+int sbusAuxGetByte(uint8_t* byte);
+
+// Setup general SBUS input source
+void sbusSetGetByte(int (*fct)(uint8_t*));
+
 void processSbusInput();
 
 #endif // _SBUS_H_
diff --git a/radio/src/serial.cpp b/radio/src/serial.cpp
index 0df948283..8c9460f65 100644
--- a/radio/src/serial.cpp
+++ b/radio/src/serial.cpp
@@ -24,42 +24,279 @@
 #include <stdarg.h>
 #include <stdio.h>
 #include "aux_serial_driver.h"
+#include "hal/serial_port.h"
 
 #define PRINTF_BUFFER_SIZE    128
 
-void serialPutc(char c) {
-#if !defined(BOOT) && defined(USB_SERIAL)
-  if (getSelectedUsbMode() == USB_SERIAL_MODE)
-    usbSerialPutc(c);
-#endif
-#if defined(AUX_SERIAL)
-  if (auxSerialTracesEnabled())
-    auxSerialPutc(c);
-#endif
-#if defined(AUX2_SERIAL)
-  if (aux2SerialTracesEnabled())
-    aux2SerialPutc(c);
-#endif
+static void (*dbg_serial_putc)(void*, uint8_t) = nullptr;
+static void* dbg_serial_ctx = nullptr;
+
+void dbgSerialSetSendCb(void* ctx, void (*cb)(void*, uint8_t))
+{
+  dbg_serial_putc = nullptr;
+  dbg_serial_ctx = ctx;
+  dbg_serial_putc = cb;
 }
 
-void serialPrintf(const char * format, ...)
+extern "C" void dbgSerialPutc(char c)
+{
+  auto _putc = dbg_serial_putc;
+  auto _ctx = dbg_serial_ctx;
+  if (_putc) _putc(_ctx, c);
+}
+
+extern "C" void dbgSerialPrintf(const char * format, ...)
 {
   va_list arglist;
   char tmp[PRINTF_BUFFER_SIZE+1];
 
+  // no need to do anything if we don't have an output
+  if (!dbg_serial_putc) return;
+  
   va_start(arglist, format);
   vsnprintf(tmp, PRINTF_BUFFER_SIZE, format, arglist);
   tmp[PRINTF_BUFFER_SIZE] = '\0';
   va_end(arglist);
 
   const char *t = tmp;
-  while (*t) {
-    serialPutc(*t++);
+  while (*t && dbg_serial_putc) {
+    dbg_serial_putc(dbg_serial_ctx, *t++);
   }
 }
 
-void serialCrlf()
+extern "C" void dbgSerialCrlf()
 {
-  serialPutc('\r');
-  serialPutc('\n');
+  dbgSerialPutc('\r');
+  dbgSerialPutc('\n');
+}
+
+static int getAuxSerialMode(uint8_t port_nr)
+{
+#if !defined(BOOT)
+  if (port_nr == 0) {
+    return g_eeGeneral.auxSerialMode;
+  }
+
+// TODO: change in datastruct_private.h
+#if defined(PCBHORUS) || defined(PCBNV14)
+  if (port_nr == 1) {
+    return g_eeGeneral.aux2SerialMode;
+  }
+#endif
+#endif
+
+  return UART_MODE_NONE;
+}
+
+struct AuxSerialPortState
+{
+  uint8_t                  mode;
+  const etx_serial_port_t* port;
+  void*                    usart_ctx;
+};
+
+static AuxSerialPortState auxSerialPortStates[MAX_AUX_SERIAL];
+
+static AuxSerialPortState* auxGetPortState(int port_nr)
+{
+  if (port_nr >= MAX_AUX_SERIAL) return nullptr;
+  return &auxSerialPortStates[port_nr];
+}
+
+// TODO: replace serialSetupCallBacks & serialSetupPort
+//       with usage based handlers.
+//
+static void serialSetCallBacks(int mode, void* ctx, const etx_serial_port_t* port)
+{
+  void (*sendByte)(void*, uint8_t) = nullptr;
+  int (*getByte)(void*, uint8_t*) = nullptr;
+
+  if (port) {
+    sendByte = port->uart->sendByte;
+    getByte = port->uart->getByte;
+  }
+  
+  switch(mode) {
+#if defined(DEBUG)
+  case UART_MODE_DEBUG:
+    // TODO: should we handle 2 outputs?
+    dbgSerialSetSendCb(ctx, sendByte);
+    (void)getByte;
+    break;
+#endif
+
+#if !defined(BOOT)
+#if defined(LUA)
+  case UART_MODE_LUA:
+    luaSetSendCb(ctx, sendByte);
+    luaSetGetSerialByte(ctx, getByte);
+    break;
+#endif
+
+#if defined(SBUS_TRAINER)
+  case UART_MODE_SBUS_TRAINER:
+    sbusSetAuxGetByte(ctx, getByte);
+    break;
+#endif
+
+  case UART_MODE_TELEMETRY:
+    telemetrySetGetByte(ctx, getByte);
+    break;
+
+  case UART_MODE_TELEMETRY_MIRROR:
+    telemetrySetMirrorCb(ctx, sendByte);
+    break;
+#endif
+  }
+}
+
+static void serialSetupPort(int mode, etx_serial_init& params, bool& power_required)
+{
+  switch (mode) {
+
+#if defined(DEBUG) || defined(CLI)
+  case UART_MODE_DEBUG:
+    params.baudrate = DEBUG_BAUDRATE;
+    break;
+#endif
+
+#if !defined(BOOT)
+  case UART_MODE_TELEMETRY_MIRROR:
+    // TODO: query telemetry baudrate / add setting for module
+    power_required = true;
+#if defined(CROSSFIRE)
+    if (modelTelemetryProtocol() == PROTOCOL_TELEMETRY_CROSSFIRE) {
+      params.baudrate = CROSSFIRE_TELEM_MIRROR_BAUDRATE;
+      break;
+    }
+#endif
+    params.baudrate = FRSKY_TELEM_MIRROR_BAUDRATE;
+    break;
+
+  case UART_MODE_TELEMETRY:
+    if (modelTelemetryProtocol() == PROTOCOL_TELEMETRY_FRSKY_D_SECONDARY) {
+      params.baudrate = FRSKY_D_BAUDRATE;
+      params.rx_enable = true;
+      power_required = true;
+    }
+    break;
+
+  case UART_MODE_SBUS_TRAINER:
+    params.baudrate = SBUS_BAUDRATE;
+    params.word_length = ETX_WordLength_9;
+    params.parity = ETX_Parity_Even;
+    params.stop_bits = ETX_StopBits_Two;
+    params.rx_enable = true;
+    power_required = true;
+    break;
+
+#if defined(LUA)
+  case UART_MODE_LUA:
+    params.baudrate = LUA_DEFAULT_BAUDRATE;
+    params.rx_enable = true;
+    power_required = true;
+    break;
+#endif
+#endif
+  }
+}
+
+void serialInit(int port_nr, int mode)
+{
+  if (port_nr >= MAX_AUX_SERIAL) return;
+  
+  auto state = auxGetPortState(port_nr);
+  if (!state) return;
+
+  auto port = auxSerialGetPort(port_nr);
+  if (!port) return;
+  
+  if (state->port) {
+    auto drv = state->port->uart;
+    if (drv->deinit) {
+      drv->deinit(state->usart_ctx);
+    }
+    if (state->mode != 0) {
+      // Clear callbacks
+      serialSetCallBacks(mode, nullptr, nullptr);
+    }
+    memset(state, 0, sizeof(AuxSerialPortState));
+  }
+
+  etx_serial_init params = {
+    .baudrate = 0,
+    .parity = ETX_Parity_None,
+    .stop_bits = ETX_StopBits_One,
+    .word_length = ETX_WordLength_8,
+    .rx_enable = false,
+    .on_receive = nullptr,
+    .on_error = nullptr,
+  };
+
+  bool power_required = false;
+  serialSetupPort(mode, params, power_required);
+    
+  if (params.baudrate != 0) {
+    state->mode = mode;
+    state->port = port;
+    state->usart_ctx = port->uart->init(&params);
+
+    // Set power on/off
+    if (port->set_pwr) {
+      port->set_pwr(power_required);
+    }
+
+    // Update callbacks once the port is setup
+    serialSetCallBacks(mode, state->usart_ctx, state->port);
+  }
+}
+
+void initSerialPorts()
+{
+  memset(auxSerialPortStates, 0, sizeof(auxSerialPortStates));
+  
+  for (int port_nr = 0; port_nr < MAX_AUX_SERIAL; port_nr++) {
+    auto mode = getAuxSerialMode(port_nr);
+    serialInit(port_nr, mode);
+  }
+}
+
+uint8_t serialGetMode(int port_nr)
+{
+  auto state = auxGetPortState(port_nr);
+  if (!state) return UART_MODE_NONE;
+  return state->mode;
+}
+
+uint8_t serialTracesEnabled(int port_nr)
+{
+#if defined(DEBUG)
+  return serialGetMode(port_nr) == UART_MODE_DEBUG;
+#else
+  return false;
+#endif
+}
+
+void serialStop(int port_nr)
+{
+  auto state = auxGetPortState(port_nr);
+  if (!state) return;
+
+  if (state->port) {
+    auto drv = state->port->uart;
+    if (drv && drv->deinit) {
+      drv->deinit(state->usart_ctx);
+    }
+    memset(state, 0, sizeof(AuxSerialPortState));
+  }
+}
+
+void serialPutc(int port_nr, uint8_t c)
+{
+  auto state = auxGetPortState(port_nr);
+  if (!state) return;
+
+  if (state->port) {
+    state->port->uart->sendByte(state->usart_ctx, c);
+  }  
 }
diff --git a/radio/src/serial.h b/radio/src/serial.h
index 4e596016c..a9e8133bf 100644
--- a/radio/src/serial.h
+++ b/radio/src/serial.h
@@ -22,19 +22,52 @@
 #ifndef _SERIAL_H_
 #define _SERIAL_H_
 
+#include <stdint.h>
+
+#define MAX_AUX_SERIAL 2
+
+void    initSerialPorts();
+uint8_t serialGetMode(int port_nr);
+uint8_t serialTracesEnabled(int port_nr);
+void    serialInit(int port_nr, int mode);
+void    serialStop(int port_nr);
+void    serialPutc(int port_nr, uint8_t c);
+
+#if defined(AUX_SERIAL)
+#define auxSerialSbusInit()      serialInit(0, UART_MODE_SBUS_TRAINER)
+#define auxSerialGetMode()       serialGetMode(0)
+#define auxSerialTracesEnabled() serialTracesEnabled(0)
+#define auxSerialStop()          serialStop(0)
+#define auxSerialPutc(c)         serialPutc(0, (c))
+#endif
+
+#if defined(AUX2_SERIAL)
+#define aux2SerialSbusInit()      serialInit(1, UART_MODE_SBUS_TRAINER)
+#define aux2SerialGetMode()       serialGetMode(1)
+#define aux2SerialTracesEnabled() serialTracesEnabled(1)
+#define aux2SerialStop()          serialStop(1)
+#define aux2SerialPutc(c)         serialPutc(1, (c))
+#endif
+
+//
+// Functions used by debug.h
+//
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-void serialPutc(char c);
-void serialPrintf(const char *format, ...);
-void serialCrlf();
+void dbgSerialPutc(char c);
+void dbgSerialPrintf(const char *format, ...);
+void dbgSerialCrlf();
 
 #ifdef __cplusplus
 }
 #endif
 
-#define serialPrint(...) do { serialPrintf(__VA_ARGS__); serialCrlf(); } while(0)
+#define dbgSerialPrint(...) do { dbgSerialPrintf(__VA_ARGS__); dbgSerialCrlf(); } while(0)
+
+// Debug serial callback
+void dbgSerialSetSendCb(void* ctx, void (*cb)(void*, uint8_t));
 
 #endif // _SERIAL_H_
 
diff --git a/radio/src/targets/common/arm/stm32/CMakeLists.txt b/radio/src/targets/common/arm/stm32/CMakeLists.txt
index 242b3176c..eae3fdbbd 100644
--- a/radio/src/targets/common/arm/stm32/CMakeLists.txt
+++ b/radio/src/targets/common/arm/stm32/CMakeLists.txt
@@ -29,7 +29,6 @@ set(STM32USB_SRC
 set(FIRMWARE_TARGET_SRC
   ${FIRMWARE_TARGET_SRC}
   ../common/arm/stm32/rtc_driver.cpp
-  ${AUX_SERIAL_DRIVER}
   ../common/arm/stm32/delays_driver.cpp
   ../common/arm/stm32/usb_bsp.c
   ../common/arm/stm32/usbd_desc.c
@@ -40,6 +39,18 @@ set(FIRMWARE_TARGET_SRC
   ../common/arm/stm32/usbd_hid_joystick.c
   )
 
+if(AUX_SERIAL OR AUX2_SERIAL)
+  set(FIRMWARE_TARGET_SRC ${FIRMWARE_TARGET_SRC}
+    ../common/arm/stm32/aux_serial_driver.cpp
+    )
+  if(AUX_SERIAL)
+    add_definitions(-DAUX_SERIAL)
+  endif()
+  if(AUX2_SERIAL)
+    add_definitions(-DAUX2_SERIAL)
+  endif()
+endif()
+
 if(DEBUG OR CLI OR USB_SERIAL)
   set(STM32USB_SRC
     ${STM32USB_SRC}
@@ -70,7 +81,6 @@ endif()
 
 set(FIRMWARE_SRC
   ${FIRMWARE_SRC}
-  serial.cpp
   syscalls.c
   )
 
diff --git a/radio/src/targets/common/arm/stm32/aux_serial_driver.cpp b/radio/src/targets/common/arm/stm32/aux_serial_driver.cpp
index 2c5909d5f..141a896fb 100644
--- a/radio/src/targets/common/arm/stm32/aux_serial_driver.cpp
+++ b/radio/src/targets/common/arm/stm32/aux_serial_driver.cpp
@@ -26,8 +26,71 @@
 #include "targets/horus/board.h"
 #include "aux_serial_driver.h"
 
+#include "fifo.h"
+#include "dmafifo.h"
+
+typedef DMAFifo<32> AuxSerialRxFifo;
+
+struct AuxSerialState
+{
+  Fifo<uint8_t, 512>*  txFifo;
+  AuxSerialRxFifo*     rxFifo;
+
+  const stm32_usart_t* usart;
+};
+
+static void* aux_serial_init(struct AuxSerialState* st, const etx_serial_init* params)
+{
+  stm32_usart_init(st->usart, params);
+  
+  if (params->rx_enable && st->usart->rxDMA && !params->on_receive) {
+    st->rxFifo->clear();
+    stm32_usart_init_rx_dma(st->usart, st->rxFifo->buffer(), st->rxFifo->size());
+  }
+
+  return st;
+}
+
+static void aux_serial_putc(void* ctx, uint8_t c)
+{
+  AuxSerialState* st = (AuxSerialState*)ctx;
+  if (st->txFifo->isFull()) return;
+  st->txFifo->push(c);
+
+  // Send is based on IRQ, so that this
+  // only enables the corresponding IRQ
+  stm32_usart_send_buffer(st->usart, &c, 1);
+}
+
+static void aux_serial_send_buffer(void* ctx, const uint8_t* data, uint8_t size)
+{
+  while(size > 0) {
+    aux_serial_putc(ctx, *data++);
+    size--;
+  }
+}
+
+static void aux_wait_tx_completed(void* ctx)
+{
+  // TODO
+  (void)ctx;
+}
+
+static int aux_get_byte(void* ctx, uint8_t* data)
+{
+  AuxSerialState* st = (AuxSerialState*)ctx;
+  if (!st->rxFifo) return -1;
+  return st->rxFifo->pop(*data);
+}
+
+void aux_serial_deinit(void* ctx)
+{
+  AuxSerialState* st = (AuxSerialState*)ctx;
+  stm32_usart_deinit(st->usart);
+}
+
 #if defined(AUX_SERIAL)
-uint8_t auxSerialMode = UART_MODE_COUNT;  // Prevent debug output before port is setup
+
 Fifo<uint8_t, 512> auxSerialTxFifo;
 
 #if defined(AUX_SERIAL_DMA_Stream_RX)
@@ -65,166 +128,53 @@ const stm32_usart_t auxUSART = {
 #endif
 };
 
-static bool auxSerialOnSend(uint8_t& data)
+AuxSerialState auxSerialState = {
+    .txFifo = &auxSerialTxFifo,
+    .rxFifo = &auxSerialRxFifo,
+    .usart = &auxUSART,
+};
+
+// TODO: grab context to get buffer
+static bool auxSerialOnSend(uint8_t* data)
 {
-  return auxSerialTxFifo.pop(data);
+  return auxSerialTxFifo.pop(*data);
 }
 
+// TODO: add to state
 static etx_serial_callbacks_t auxSerialCb = {
   .on_send = auxSerialOnSend,
   .on_receive = nullptr,
   .on_error = nullptr,
 };
 
-void auxSerialSetup(unsigned int baudrate, bool rx_enable, uint8_t word_length,
-                    uint8_t parity, uint8_t stop_bits)
+static void* auxSerialInit(const etx_serial_init* params)
 {
-#if defined(AUX_SERIAL_PWR_GPIO)
-  LL_GPIO_InitTypeDef pinInit;
-  LL_GPIO_StructInit(&pinInit);
-  pinInit.Pin = AUX_SERIAL_PWR_GPIO_PIN;
-  pinInit.Mode = LL_GPIO_MODE_OUTPUT;
-  pinInit.Pull = LL_GPIO_PULL_UP;
-  LL_GPIO_Init(AUX_SERIAL_PWR_GPIO, &pinInit);
-#endif
-
-#if defined(AUX_SERIAL_TX_INVERT_GPIO_PIN) // NV14
-  // TODO
-  GPIO_InitStructure.GPIO_Pin = AUX_SERIAL_TX_INVERT_GPIO_PIN;
-  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
-  GPIO_Init(AUX_SERIAL_TX_INVERT_GPIO, &GPIO_InitStructure);
-  GPIO_ResetBits(AUX_SERIAL_TX_INVERT_GPIO, AUX_SERIAL_TX_INVERT_GPIO_PIN);
-#endif
-
-#if defined(AUX_SERIAL_RX_INVERT_GPIO_PIN) // NV14
-  // TODO
-  GPIO_InitStructure.GPIO_Pin = AUX_SERIAL_RX_INVERT_GPIO_PIN;
-  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
-  GPIO_Init(AUX_SERIAL_RX_INVERT_GPIO, &GPIO_InitStructure);
-  GPIO_ResetBits(AUX_SERIAL_RX_INVERT_GPIO, AUX_SERIAL_RX_INVERT_GPIO_PIN);
-#endif
-
-  etx_serial_init serialInit = {
-    .baudrate = baudrate,
-    .parity = parity,
-    .stop_bits = stop_bits,
-    .word_length = word_length,
-    .rx_enable = rx_enable,
-    .rx_dma_buf = nullptr,
-    .rx_dma_buf_len = 0,
-    .on_receive = nullptr, // TODO
-    .on_error = nullptr,   // TODO
-  };
-
-#if defined(AUX_SERIAL_DMA_Stream_RX)
-  if (rx_enable) {
-    auxSerialRxFifo.clear();
-    serialInit.rx_dma_buf = auxSerialRxFifo.buffer();
-    serialInit.rx_dma_buf_len = auxSerialRxFifo.size();
-  }
-#endif
-  
-  stm32_usart_init(&auxUSART, &serialInit);
+  return aux_serial_init(&auxSerialState, params);
 }
 
+const etx_serial_driver_t AuxSerialDriver = {
+    .init = auxSerialInit,
+    .deinit = aux_serial_deinit,
+    .sendByte = aux_serial_putc,
+    .sendBuffer = aux_serial_send_buffer,
+    .waitForTxCompleted = aux_wait_tx_completed,
+    .getByte = aux_get_byte,
+    .setReceiveCb = nullptr,
+    .setOnErrorCb = nullptr,
+};
+
 extern "C" void AUX_SERIAL_USART_IRQHandler(void)
 {
   DEBUG_INTERRUPT(INT_SER2);
   stm32_usart_isr(&auxUSART, &auxSerialCb);
 }
 
-void auxSerialPutc(uint8_t c)
-{
-  if (auxSerialTxFifo.isFull()) return;
-  auxSerialTxFifo.push(c);
-  stm32_usart_send_buffer(&auxUSART, &c, 1);
-}
-
-void auxSerialStop()
-{
-  stm32_usart_deinit(&auxUSART);
-}
-
-static void serialPushLua(uint8_t data)
-{
-  // TODO: this should be set by LUA instead of
-  //       including some LUA header here.
-  //
-  // if (luaRxFifo)
-  //   luaRxFifo->push(data);
-}
-
-void auxSerialInit(unsigned int mode, unsigned int protocol)
-{
-  auxSerialStop();
-
-  auxSerialMode = mode;
-  auxSerialCb.on_receive = nullptr;
-
-  switch (mode) {
-    case UART_MODE_TELEMETRY_MIRROR:
-      // TODO: add a setting for the telemetry protocol ???
-      // -> how do we know the baudrate?
-#if defined(CROSSFIRE)
-      if (protocol == PROTOCOL_TELEMETRY_CROSSFIRE) {
-        auxSerialSetup(CROSSFIRE_TELEM_MIRROR_BAUDRATE, false);
-        AUX_SERIAL_POWER_ON();
-        break;
-      }
-#endif
-      auxSerialSetup(FRSKY_TELEM_MIRROR_BAUDRATE, false);
-      AUX_SERIAL_POWER_ON();
-      break;
-
-#if defined(DEBUG) || defined(CLI)
-    case UART_MODE_DEBUG:
-      auxSerialSetup(DEBUG_BAUDRATE, false);
-      AUX_SERIAL_POWER_OFF();
-      break;
-#endif
-
-    case UART_MODE_TELEMETRY:
-      if (protocol == PROTOCOL_TELEMETRY_FRSKY_D_SECONDARY) {
-        auxSerialSetup(FRSKY_D_BAUDRATE, true);
-        AUX_SERIAL_POWER_ON();
-      }
-      break;
-
-    case UART_MODE_SBUS_TRAINER:
-      auxSerialSetup(
-          SBUS_BAUDRATE, true, ETX_WordLength_9, ETX_Parity_Even,
-          ETX_StopBits_Two);  // USART_WordLength_9b due to parity bit
-      AUX_SERIAL_POWER_ON();
-      break;
-
-#if defined(LUA)
-    case UART_MODE_LUA:
-      auxSerialSetup(LUA_DEFAULT_BAUDRATE, false);
-      auxSerialCb.on_receive = serialPushLua;
-      AUX_SERIAL_POWER_ON();
-      break;
-#endif
-  }
-}
-
-void auxSerialSbusInit()
-{
-  auxSerialInit(UART_MODE_SBUS_TRAINER, 0);
-}
-
-uint8_t auxSerialTracesEnabled()
-{
-#if defined(DEBUG)
-  return (auxSerialMode == UART_MODE_DEBUG);
-#else
-  return false;
-#endif
-}
 #endif // AUX_SERIAL
 
 #if defined(AUX2_SERIAL)
-uint8_t aux2SerialMode = UART_MODE_COUNT;  // Prevent debug output before port is setup
+
 Fifo<uint8_t, 512> aux2SerialTxFifo;
+
 AuxSerialRxFifo aux2SerialRxFifo __DMA (AUX2_SERIAL_DMA_Stream_RX);
 
 const LL_GPIO_InitTypeDef aux2USARTPinInit = {
@@ -250,9 +200,15 @@ const stm32_usart_t aux2USART = {
   .rxDMA_Channel = AUX2_SERIAL_DMA_Channel_RX,
 };
 
-static bool aux2SerialOnSend(uint8_t& data)
+AuxSerialState aux2SerialState = {
+    .txFifo = &aux2SerialTxFifo,
+    .rxFifo = &aux2SerialRxFifo,
+    .usart = &aux2USART,
+};
+
+static bool aux2SerialOnSend(uint8_t* data)
 {
-  return aux2SerialTxFifo.pop(data);
+  return aux2SerialTxFifo.pop(*data);
 }
 
 static etx_serial_callbacks_t aux2SerialCb = {
@@ -261,35 +217,9 @@ static etx_serial_callbacks_t aux2SerialCb = {
   .on_error = nullptr,
 };
 
-void aux2SerialSetup(unsigned int baudrate, bool rx_enable, uint8_t word_length,
-                     uint8_t parity, uint8_t stop_bits)
+void* aux2SerialInit(const etx_serial_init* params)
 {
-  etx_serial_init serialInit = {
-    .baudrate = baudrate,
-    .parity = parity,
-    .stop_bits = stop_bits,
-    .word_length = word_length,
-    .rx_enable = rx_enable,
-    .rx_dma_buf = nullptr,
-    .rx_dma_buf_len = 0,
-    .on_receive = nullptr, // TODO
-    .on_error = nullptr,   // TODO
-  };
-
-  if (rx_enable) {
-    aux2SerialRxFifo.clear();
-    serialInit.rx_dma_buf = aux2SerialRxFifo.buffer();
-    serialInit.rx_dma_buf_len = aux2SerialRxFifo.size();
-  }
-
-  stm32_usart_init(&aux2USART, &serialInit);
-  
-// #if defined(AUX2_SERIAL_PWR_GPIO)
-//   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
-//   GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
-//   GPIO_InitStructure.GPIO_Pin = AUX2_SERIAL_PWR_GPIO_PIN;
-//   GPIO_Init(AUX2_SERIAL_PWR_GPIO, &GPIO_InitStructure);
-// #endif
+  return aux_serial_init(&aux2SerialState, params);
 }
 
 extern "C" void AUX2_SERIAL_USART_IRQHandler(void)
@@ -298,81 +228,15 @@ extern "C" void AUX2_SERIAL_USART_IRQHandler(void)
   stm32_usart_isr(&aux2USART, &aux2SerialCb);
 }
 
-void aux2SerialPutc(uint8_t c)
-{
-  if (aux2SerialTxFifo.isFull()) return;
-  aux2SerialTxFifo.push(c);
-  stm32_usart_send_buffer(&aux2USART, &c, 1);
-}
-
-void aux2SerialStop()
-{
-  stm32_usart_deinit(&aux2USART);
-}
-
-void aux2SerialInit(unsigned int mode, unsigned int protocol)
-{
-  aux2SerialStop();
-
-  aux2SerialMode = mode;
-  aux2SerialCb.on_receive = nullptr;
-
-  switch (mode) {
-    case UART_MODE_TELEMETRY_MIRROR:
-#if defined(CROSSFIRE)
-      if (protocol == PROTOCOL_TELEMETRY_CROSSFIRE) {
-        aux2SerialSetup(CROSSFIRE_TELEM_MIRROR_BAUDRATE, false);
-        AUX2_SERIAL_POWER_ON();
-        break;
-      }
-#endif
-      aux2SerialSetup(FRSKY_TELEM_MIRROR_BAUDRATE, false);
-      AUX2_SERIAL_POWER_ON();
-      break;
-
-#if defined(DEBUG) || defined(CLI)
-    case UART_MODE_DEBUG:
-      aux2SerialSetup(DEBUG_BAUDRATE, false);
-      AUX2_SERIAL_POWER_OFF();
-      break;
-#endif
-
-    case UART_MODE_TELEMETRY:
-      if (protocol == PROTOCOL_TELEMETRY_FRSKY_D_SECONDARY) {
-        aux2SerialSetup(FRSKY_D_BAUDRATE, true);
-        AUX2_SERIAL_POWER_ON();
-      }
-      break;
-
-    case UART_MODE_SBUS_TRAINER:
-      aux2SerialSetup(
-          SBUS_BAUDRATE, true, ETX_WordLength_9, ETX_Parity_Even,
-          ETX_StopBits_Two);  // 2 stop bits requires USART_WordLength_9b
-      AUX2_SERIAL_POWER_ON();
-      break;
-
-#if defined(LUA)
-    case UART_MODE_LUA:
-      aux2SerialSetup(LUA_DEFAULT_BAUDRATE, false);
-      aux2SerialCb.on_receive = serialPushLua;
-      AUX2_SERIAL_POWER_ON();
-      break;
-#endif
-  }
-}
-
-void aux2SerialSbusInit()
-{
-  aux2SerialInit(UART_MODE_SBUS_TRAINER, 0);
-}
-
-uint8_t aux2SerialTracesEnabled()
-{
-#if defined(DEBUG)
-  return (aux2SerialMode == UART_MODE_DEBUG);
-#else
-  return false;
-#endif
-}
+const etx_serial_driver_t Aux2SerialDriver = {
+    .init = aux2SerialInit,
+    .deinit = aux_serial_deinit,
+    .sendByte = aux_serial_putc,
+    .sendBuffer = aux_serial_send_buffer,
+    .waitForTxCompleted = aux_wait_tx_completed,
+    .getByte = aux_get_byte,
+    .setReceiveCb = nullptr,
+    .setOnErrorCb = nullptr,
+};
 
 #endif // AUX2_SERIAL
diff --git a/radio/src/targets/common/arm/stm32/aux_serial_driver.h b/radio/src/targets/common/arm/stm32/aux_serial_driver.h
index 3dd733d0d..6debae13f 100644
--- a/radio/src/targets/common/arm/stm32/aux_serial_driver.h
+++ b/radio/src/targets/common/arm/stm32/aux_serial_driver.h
@@ -24,28 +24,12 @@
 #include "hal/serial_driver.h"
 
 #if defined(AUX_SERIAL)
-extern uint8_t auxSerialMode;
-void auxSerialSetup(unsigned int baudrate, bool rx_enable,
-                    uint8_t word_length = ETX_WordLength_8,
-                    uint8_t parity = ETX_Parity_None,
-                    uint8_t stop_bits = ETX_StopBits_One);
-void auxSerialInit(unsigned int mode, unsigned int protocol);
-void auxSerialPutc(uint8_t c);
-void auxSerialSbusInit();
-void auxSerialStop();
-uint8_t auxSerialTracesEnabled();
+
+extern const etx_serial_driver_t AuxSerialDriver;
 #endif
 
 #if defined(AUX2_SERIAL)
-extern uint8_t aux2SerialMode;
-void aux2SerialSetup(unsigned int baudrate, bool rx_enable,
-                    uint8_t word_length = ETX_WordLength_8,
-                    uint8_t parity = ETX_Parity_None,
-                    uint8_t stop_bits = ETX_StopBits_One);
-void aux2SerialInit(unsigned int mode, unsigned int protocol);
-void aux2SerialPutc(uint8_t c);
-void aux2SerialSbusInit();
-void aux2SerialStop();
-uint8_t aux2SerialTracesEnabled();
+
+extern const etx_serial_driver_t Aux2SerialDriver;
 #endif
 
diff --git a/radio/src/targets/common/arm/stm32/bootloader/CMakeLists.txt b/radio/src/targets/common/arm/stm32/bootloader/CMakeLists.txt
index bd8403077..64ba5f989 100644
--- a/radio/src/targets/common/arm/stm32/bootloader/CMakeLists.txt
+++ b/radio/src/targets/common/arm/stm32/bootloader/CMakeLists.txt
@@ -144,6 +144,7 @@ if(PCB STREQUAL X10 OR PCB STREQUAL X12S OR PCB STREQUAL NV14)
       ../../../../../${STM32LIB_DIR}/STM32F4xx_StdPeriph_Driver/src/stm32f4xx_usart.c
       ../../../../../serial.cpp
       ../../../../../targets/common/arm/stm32/aux_serial_driver.cpp
+      ../../../../../targets/common/arm/stm32/stm32_usart_driver.cpp
       )
   endif()
 else()
diff --git a/radio/src/targets/common/arm/stm32/bootloader/boot.cpp b/radio/src/targets/common/arm/stm32/bootloader/boot.cpp
index 6697f8edd..2dbe723bc 100644
--- a/radio/src/targets/common/arm/stm32/bootloader/boot.cpp
+++ b/radio/src/targets/common/arm/stm32/bootloader/boot.cpp
@@ -244,12 +244,9 @@ int main()
 #endif
 
   delaysInit(); // needed for lcdInit()
-
-#if defined(DEBUG) && defined(AUX_SERIAL)
-  auxSerialInit(UART_MODE_DEBUG, 0); // default serial mode (None if DEBUG not defined)
-#endif
-#if defined(DEBUG) && defined(AUX2_SERIAL)
-  aux2SerialInit(UART_MODE_DEBUG, 0); // default serial mode (None if DEBUG not defined)
+  
+#if defined(DEBUG)
+  initSerialPorts();
 #endif
 
   __enable_irq();
diff --git a/radio/src/targets/common/arm/stm32/extmodule_serial_driver.cpp b/radio/src/targets/common/arm/stm32/extmodule_serial_driver.cpp
index edd277928..648b6464b 100644
--- a/radio/src/targets/common/arm/stm32/extmodule_serial_driver.cpp
+++ b/radio/src/targets/common/arm/stm32/extmodule_serial_driver.cpp
@@ -49,8 +49,6 @@ static const etx_serial_init extmoduleSerialParams = {
   .stop_bits = ETX_StopBits_One,
   .word_length = ETX_WordLength_8,
   .rx_enable = true,
-  .rx_dma_buf = nullptr,
-  .rx_dma_buf_len = 0,
   .on_receive = extmoduleFifoReceive,
   .on_error = extmoduleFifoError,
 };
@@ -78,9 +76,9 @@ static const stm32_usart_t extmoduleUSART = {
   .rxDMA_Channel = 0,
 };
 
-static void extmoduleSerialStart(const etx_serial_init* params)
+static void* extmoduleSerialStart(const etx_serial_init* params)
 {
-  if (!params) return;
+  if (!params) return nullptr;
     
   extmodule_driver.on_receive = params->on_receive;
   extmodule_driver.on_error = params->on_error;
@@ -88,6 +86,8 @@ static void extmoduleSerialStart(const etx_serial_init* params)
   // UART config
   stm32_usart_init(&extmoduleUSART, params);
   extmoduleFifo.clear();
+
+  return nullptr;
 }
 
 void extmoduleInvertedSerialStart(uint32_t baudrate)
@@ -108,7 +108,7 @@ void extmodulePxx1SerialStart()
 }
 #endif
 
-void extmoduleSerialStop()
+void extmoduleSerialStop(void*)
 {
   stm32_usart_deinit(&extmoduleUSART);
 
@@ -117,18 +117,18 @@ void extmoduleSerialStop()
   extmodule_driver.on_error = nullptr;
 }
 
-static void extmoduleSendByte(uint8_t byte)
+static void extmoduleSendByte(void*, uint8_t byte)
 {
   stm32_usart_send_byte(&extmoduleUSART, byte);
 }
 
-static void extmoduleSendBuffer(const uint8_t * data, uint8_t size)
+static void extmoduleSendBuffer(void*, const uint8_t * data, uint8_t size)
 {
   if (size == 0) return;
   stm32_usart_send_buffer(&extmoduleUSART, data, size);
 }
 
-static void extmoduleWaitForTxCompleted()
+static void extmoduleWaitForTxCompleted(void*)
 {
   stm32_usart_wait_for_tx_dma(&extmoduleUSART);
 }
diff --git a/radio/src/targets/common/arm/stm32/f4/CMakeLists.txt b/radio/src/targets/common/arm/stm32/f4/CMakeLists.txt
index 9b7c61bb0..761c7e671 100644
--- a/radio/src/targets/common/arm/stm32/f4/CMakeLists.txt
+++ b/radio/src/targets/common/arm/stm32/f4/CMakeLists.txt
@@ -20,6 +20,7 @@ target_include_directories(stm32cube_ll PRIVATE
   ${THIRDPARTY_DIR}/CMSIS/Include)
 
 set(FIRMWARE_SRC ${FIRMWARE_SRC} $<TARGET_OBJECTS:stm32cube_ll>)
+set(BOOTLOADER_SRC ${BOOTLOADER_SRC} $<TARGET_OBJECTS:stm32cube_ll>)
 
 # StdPeriph library
 set(STM32LIB_DIR ${THIRDPARTY_DIR}/STM32F4xx_DSP_StdPeriph_Lib_V1.8.0/Libraries)
diff --git a/radio/src/targets/common/arm/stm32/intmodule_serial_driver.cpp b/radio/src/targets/common/arm/stm32/intmodule_serial_driver.cpp
index 126cb58d4..7e487e2a9 100755
--- a/radio/src/targets/common/arm/stm32/intmodule_serial_driver.cpp
+++ b/radio/src/targets/common/arm/stm32/intmodule_serial_driver.cpp
@@ -28,13 +28,13 @@
 ModuleFifo intmoduleFifo;
 
 #if !defined(INTMODULE_DMA_STREAM)
-uint8_t * intmoduleTxBufferData;
-volatile uint8_t intmoduleTxBufferRemaining;
+static uint8_t * intmoduleTxBufferData;
+static volatile uint8_t intmoduleTxBufferRemaining;
 
-bool intmoduleTxBufferSend(uint8_t& data)
+bool intmoduleTxBufferSend(uint8_t* data)
 {
   if (intmoduleTxBufferRemaining) {
-    data = *(intmoduleTxBufferData++);
+    *data = *(intmoduleTxBufferData++);
     intmoduleTxBufferRemaining--;
     return true;
   }
@@ -96,9 +96,15 @@ void intmoduleStop()
   intmodule_driver.on_error = nullptr;
 }
 
-void intmoduleSerialStart(const etx_serial_init* params)
+static void intmoduleStop(void* ctx)
 {
-  if (!params) return;
+  (void)ctx;
+  intmoduleStop();
+}
+
+void* intmoduleSerialStart(const etx_serial_init* params)
+{
+  if (!params) return nullptr;
 
   // TODO: sanity check parameters
   //  - the UART seems to block when initialised with baudrate = 0
@@ -108,6 +114,7 @@ void intmoduleSerialStart(const etx_serial_init* params)
   intmodule_driver.on_error = params->on_error;
 
   stm32_usart_init(&intmoduleUSART, params);
+  return nullptr;
 }
 
 #define USART_FLAG_ERRORS (USART_FLAG_ORE | USART_FLAG_NE | USART_FLAG_FE | USART_FLAG_PE)
@@ -116,13 +123,15 @@ extern "C" void INTMODULE_USART_IRQHandler(void)
   stm32_usart_isr(&intmoduleUSART, &intmodule_driver);
 }
 
-void intmoduleSendByte(uint8_t byte)
+void intmoduleSendByte(void* ctx, uint8_t byte)
 {
+  (void)ctx;
   stm32_usart_send_byte(&intmoduleUSART, byte);
 }
 
-void intmoduleSendBuffer(const uint8_t * data, uint8_t size)
+void intmoduleSendBuffer(void* ctx, const uint8_t * data, uint8_t size)
 {
+  (void)ctx;
   if (size == 0)
     return;
 
@@ -133,8 +142,9 @@ void intmoduleSendBuffer(const uint8_t * data, uint8_t size)
   stm32_usart_send_buffer(&intmoduleUSART, data, size);
 }
 
-void intmoduleWaitForTxCompleted()
+void intmoduleWaitForTxCompleted(void* ctx)
 {
+  (void)ctx;
 #if defined(INTMODULE_DMA_STREAM)
   stm32_usart_wait_for_tx_dma(&intmoduleUSART);
 #else
diff --git a/radio/src/targets/common/arm/stm32/stm32_usart_driver.cpp b/radio/src/targets/common/arm/stm32/stm32_usart_driver.cpp
index aa29225b9..5ac82b0b8 100644
--- a/radio/src/targets/common/arm/stm32/stm32_usart_driver.cpp
+++ b/radio/src/targets/common/arm/stm32/stm32_usart_driver.cpp
@@ -22,8 +22,16 @@
 #include "stm32_usart_driver.h"
 #include <string.h>
 
-static void stm32_usart_init_rx_dma(const stm32_usart_t* usart, void* buffer, uint32_t length)
+void stm32_usart_init_rx_dma(const stm32_usart_t* usart, void* buffer, uint32_t length)
 {
+  // Disable IRQ based RX
+  LL_USART_DisableIT_RXNE(usart->USARTx);
+
+  // In case TX DMA is used, disable the ISR completely
+  if (usart->txDMA) {
+    NVIC_DisableIRQ(usart->IRQn);
+  }
+
   LL_DMA_InitTypeDef dmaInit;
   LL_DMA_StructInit(&dmaInit);
   dmaInit.Channel = usart->rxDMA_Channel;
@@ -47,6 +55,8 @@ void stm32_usart_init(const stm32_usart_t* usart, const etx_serial_init* params)
   LL_GPIO_Init(usart->GPIOx, (LL_GPIO_InitTypeDef*)usart->pinInit);
   
   LL_USART_InitTypeDef usartInit;
+  LL_USART_StructInit(&usartInit);
+
   usartInit.BaudRate = params->baudrate;
 
   uint32_t parity = LL_USART_PARITY_NONE;
@@ -96,14 +106,8 @@ void stm32_usart_init(const stm32_usart_t* usart, const etx_serial_init* params)
 
   // Enable RX IRQ
   if (params->rx_enable) {
-    if (usart->rxDMA) {
-      // RX DMA
-      stm32_usart_init_rx_dma(usart, params->rx_dma_buf,
-                              params->rx_dma_buf_len);
-    } else {
-      // IRQ based RX
-      LL_USART_EnableIT_RXNE(usart->USARTx);
-    }
+    // IRQ based RX
+    LL_USART_EnableIT_RXNE(usart->USARTx);
   }
 
   if (!usart->txDMA || (params->rx_enable && !usart->rxDMA)) {
@@ -159,7 +163,7 @@ void stm32_usart_send_buffer(const stm32_usart_t* usart, const uint8_t * data, u
     return;
   } else {
     // Please note that we don't use the buffer:
-    // it should set internally by the driver user
+    // it should be set internally by the driver user
     // and each byte is returned individually by on_send()
     LL_USART_EnableIT_TXE(usart->USARTx);
   }
@@ -204,7 +208,7 @@ void stm32_usart_isr(const stm32_usart_t* usart, etx_serial_callbacks_t* cb)
   uint32_t status = LL_USART_ReadReg(usart->USARTx, SR);
 
   // Receive: do it first as it is more time critical
-  if (LL_USART_IsEnabledIT_TXE(usart->USARTx)) {
+  if (LL_USART_IsEnabledIT_RXNE(usart->USARTx)) {
 
     // Drain RX
     while (status & (LL_USART_SR_RXNE | USART_FLAG_ERRORS)) {
@@ -229,7 +233,7 @@ void stm32_usart_isr(const stm32_usart_t* usart, etx_serial_callbacks_t* cb)
   if (LL_USART_IsEnabledIT_TXE(usart->USARTx) && (status & LL_USART_SR_TXE)) {
 
     uint8_t data;
-    if (cb->on_send && cb->on_send(data)) {
+    if (cb->on_send && cb->on_send(&data)) {
       LL_USART_TransmitData8(usart->USARTx, data);
     } else {
       LL_USART_DisableIT_TXE(usart->USARTx);
diff --git a/radio/src/targets/common/arm/stm32/stm32_usart_driver.h b/radio/src/targets/common/arm/stm32/stm32_usart_driver.h
index d1a0d7eed..1671d49b4 100644
--- a/radio/src/targets/common/arm/stm32/stm32_usart_driver.h
+++ b/radio/src/targets/common/arm/stm32/stm32_usart_driver.h
@@ -48,10 +48,10 @@ struct stm32_usart_t {
 };
 
 void stm32_usart_init(const stm32_usart_t* usart, const etx_serial_init* params);
+void stm32_usart_init_rx_dma(const stm32_usart_t* usart, void* buffer, uint32_t length);
 void stm32_usart_deinit(const stm32_usart_t* usart);
 void stm32_usart_send_byte(const stm32_usart_t* usart, uint8_t byte);
 void stm32_usart_send_buffer(const stm32_usart_t* usart, const uint8_t * data, uint32_t size);
 void stm32_usart_wait_for_tx_dma(const stm32_usart_t* usart);
 void stm32_usart_isr(const stm32_usart_t* usart, etx_serial_callbacks_t* cb);
 
-
diff --git a/radio/src/targets/common/arm/stm32/usb_driver.h b/radio/src/targets/common/arm/stm32/usb_driver.h
index cf86cbea1..a12d319c7 100644
--- a/radio/src/targets/common/arm/stm32/usb_driver.h
+++ b/radio/src/targets/common/arm/stm32/usb_driver.h
@@ -51,7 +51,7 @@ int  getSelectedUsbMode();
 void setSelectedUsbMode(int mode);
 
 uint32_t usbSerialFreeSpace();
-void     usbSerialPutc(uint8_t c);
+void     usbSerialPutc(void*, uint8_t c);
 
 uint32_t usbSerialBaudRate(void);
 
diff --git a/radio/src/targets/common/arm/stm32/usbd_cdc.cpp b/radio/src/targets/common/arm/stm32/usbd_cdc.cpp
index 3879d74e7..2a005a221 100644
--- a/radio/src/targets/common/arm/stm32/usbd_cdc.cpp
+++ b/radio/src/targets/common/arm/stm32/usbd_cdc.cpp
@@ -94,6 +94,7 @@ static uint16_t VCP_Init(void)
   cdcConnected = true;
   ctrlLineStateCb = NULL;
   baudRateCb = NULL;
+
   return USBD_OK;
 }
 
@@ -205,7 +206,7 @@ uint32_t usbSerialFreeSpace()
          1;
 }
 
-void usbSerialPutc(uint8_t c)
+void usbSerialPutc(void*, uint8_t c)
 {
   /*
     Apparently there is no reliable way to tell if the
@@ -253,21 +254,8 @@ void usbSerialPutc(uint8_t c)
   */
 static uint16_t VCP_DataRx (uint8_t* Buf, uint32_t Len)
 {
-  if (receiveDataCb)
-    receiveDataCb(Buf, Len);
-  
-// #if defined(CLI)
-//   // pass data to CLI
-//   cliReceiveData(Buf, Len);
-// #elif defined(LUA)  
-//   // copy data to the LUA FIFO
-//   if (luaRxFifo) {
-//     for (uint32_t i = 0; i < Len; i++) {
-//       luaRxFifo->push(Buf[i]);
-//     }
-//   }
-// #endif
-
+  auto _rxCb = receiveDataCb;
+  if (_rxCb) _rxCb(Buf, Len);
   return USBD_OK;
 }
 
diff --git a/radio/src/targets/horus/CMakeLists.txt b/radio/src/targets/horus/CMakeLists.txt
index 870b2f89e..8229e8845 100644
--- a/radio/src/targets/horus/CMakeLists.txt
+++ b/radio/src/targets/horus/CMakeLists.txt
@@ -245,16 +245,6 @@ if(BLUETOOTH)
   add_definitions(-DHARDWARE_TRAINER_BLUETOOTH)
 endif()
 
-if (AUX_SERIAL)
-  add_definitions(-DAUX_SERIAL)
-  set(AUX_SERIAL_DRIVER ../common/arm/stm32/aux_serial_driver.cpp)
-endif()
-
-if (AUX2_SERIAL)
-  add_definitions(-DAUX2_SERIAL)
-  set(AUX_SERIAL_DRIVER ../common/arm/stm32/aux_serial_driver.cpp)
-endif()
-
 if (SBUS_TRAINER)
   add_definitions(-DSBUS_TRAINER)
   set(SRC
@@ -266,7 +256,6 @@ endif()
 set(FIRMWARE_TARGET_SRC
   ${FIRMWARE_TARGET_SRC}
   ${LCD_DRIVER}
-  ${AUX_SERIAL_DRIVER}
   ${FLYSKY_HALL_STICKS_DRIVER}
   ${IMU_LSM6DS33_DRIVER}
   ${TOUCH_DRIVER}
diff --git a/radio/src/targets/horus/board.cpp b/radio/src/targets/horus/board.cpp
index fccc3036a..8dbc178fb 100644
--- a/radio/src/targets/horus/board.cpp
+++ b/radio/src/targets/horus/board.cpp
@@ -19,13 +19,21 @@
  * GNU General Public License for more details.
  */
 
+#include "stm32_hal_ll.h"
 #include "opentx.h"
 
 #include "hal/adc_driver.h"
-#include "../common/arm/stm32/timers_driver.h"
+#include "hal/serial_driver.h"
+#include "hal/serial_port.h"
+
+#include "timers_driver.h"
+
+#if defined(AUX_SERIAL) || defined(AUX2_SERIAL)
+#include "aux_serial_driver.h"
+#endif
 
 #if !defined(PCBX12S)
-  #include "../common/arm/stm32/stm32_hal_adc.h"
+  #include "stm32_hal_adc.h"
   #define ADC_DRIVER stm32_hal_adc_driver
 #else
   #include "x12s_adc_driver.h"
@@ -58,30 +66,6 @@ void watchdogInit(unsigned int duration)
   IWDG->KR = 0xCCCC;      // start
 }
 
-#if defined(AUX_SERIAL_PWR_GPIO)
-void auxSerialPowerOn()
-{
-  GPIO_SetBits(AUX_SERIAL_PWR_GPIO, AUX_SERIAL_PWR_GPIO_PIN);
-}
-
-void auxSerialPowerOff()
-{
-  GPIO_ResetBits(AUX_SERIAL_PWR_GPIO, AUX_SERIAL_PWR_GPIO_PIN);
-}
-#endif
-#if defined(AUX2_SERIAL_PWR_GPIO)
-void aux2SerialPowerOn()
-{
-  GPIO_SetBits(AUX2_SERIAL_PWR_GPIO, AUX2_SERIAL_PWR_GPIO_PIN);
-}
-
-void aux2SerialPowerOff()
-{
-  GPIO_ResetBits(AUX2_SERIAL_PWR_GPIO, AUX2_SERIAL_PWR_GPIO_PIN);
-}
-#endif
-
-
 #if HAS_SPORT_UPDATE_CONNECTOR()
 void sportUpdateInit()
 {
@@ -193,12 +177,7 @@ void boardInit()
 
   __enable_irq();
 
-#if defined(DEBUG) && defined(AUX_SERIAL)
-  auxSerialInit(UART_MODE_DEBUG, 0); // default serial mode (None if DEBUG not defined)
-#endif
-#if defined(DEBUG) && defined(AUX2_SERIAL)
-  aux2SerialInit(UART_MODE_DEBUG, 0); // default serial mode (None if DEBUG not defined)
-#endif
+  initSerialPorts();
 
   TRACE("\nHorus board started :)");
   TRACE("RCC->CSR = %08x", RCC->CSR);
@@ -359,3 +338,64 @@ bool isBacklightEnabled()
     return true;
   return boardBacklightOn;
 }
+
+static void _aux_pwr(GPIO_TypeDef *GPIOx, uint32_t pin, uint8_t on)
+{
+  LL_GPIO_InitTypeDef pinInit;
+  LL_GPIO_StructInit(&pinInit);
+  pinInit.Pin = pin;
+  pinInit.Mode = LL_GPIO_MODE_OUTPUT;
+  pinInit.Pull = LL_GPIO_PULL_UP;
+  LL_GPIO_Init(GPIOx, &pinInit);
+
+  if (on) {
+    LL_GPIO_SetOutputPin(GPIOx, pin);
+  } else {
+    LL_GPIO_ResetOutputPin(GPIOx, pin);
+  }
+}
+
+#if defined(AUX_SERIAL)
+void set_aux_pwr(uint8_t on)
+{
+#if defined(AUX_SERIAL_PWR_GPIO)
+  _aux_pwr(AUX_SERIAL_PWR_GPIO, AUX_SERIAL_PWR_GPIO_PIN, on);
+#endif
+}
+
+const etx_serial_port_t auxSerialPort = {
+  &AuxSerialDriver,
+  set_aux_pwr,
+};
+#define AUX_SERIAL_PORT &auxSerialPort
+#else
+#define AUX_SERIAL_PORT nullptr
+#endif
+
+#if defined(AUX2_SERIAL)
+void set_aux2_pwr(uint8_t on)
+{
+#if defined(AUX2_SERIAL_PWR_GPIO)
+  _aux_pwr(AUX2_SERIAL_PWR_GPIO, AUX2_SERIAL_PWR_GPIO_PIN, on);
+#endif
+}
+
+const etx_serial_port_t aux2SerialPort = {
+  &Aux2SerialDriver,
+  set_aux2_pwr,
+};
+#define AUX2_SERIAL_PORT &aux2SerialPort
+#else
+#define AUX2_SERIAL_PORT nullptr
+#endif // AUX2_SERIAL
+
+static const etx_serial_port_t* serialPorts[MAX_AUX_SERIAL] = {
+  AUX_SERIAL_PORT,
+  AUX2_SERIAL_PORT,
+};
+
+const etx_serial_port_t* auxSerialGetPort(int port_nr)
+{
+  if (port_nr >= MAX_AUX_SERIAL) return nullptr;
+  return serialPorts[port_nr];
+}
diff --git a/radio/src/targets/horus/board.h b/radio/src/targets/horus/board.h
index 936da58b6..038d8693f 100644
--- a/radio/src/targets/horus/board.h
+++ b/radio/src/targets/horus/board.h
@@ -26,6 +26,7 @@
 #include "opentx_constants.h"
 #include "board_common.h"
 #include "hal.h"
+#include "hal/serial_port.h"
 
 #include "watchdog_driver.h"
 
@@ -198,9 +199,6 @@ void stop_trainer_ppm();
 void init_trainer_capture();
 void stop_trainer_capture();
 
-// SBUS
-int sbusGetByte(uint8_t * byte);
-
 // Keys driver
 enum EnumKeys
 {
@@ -623,7 +621,7 @@ void telemetryPortSetDirectionInput();
 void telemetryPortSetDirectionOutput();
 void sportSendByte(uint8_t byte);
 void sportSendBuffer(const uint8_t * buffer, uint32_t count);
-bool telemetryGetByte(uint8_t * byte);
+bool sportGetByte(uint8_t * byte);
 void telemetryClearFifo();
 extern uint32_t telemetryErrors;
 
@@ -654,32 +652,8 @@ void sportUpdatePowerInit();
   #define DEBUG_BAUDRATE                  115200
   #define LUA_DEFAULT_BAUDRATE            115200
 #endif
-#if defined(AUX_SERIAL)
-#define auxSerialTelemetryInit(protocol) auxSerialInit(UART_MODE_TELEMETRY, protocol)
-void auxSerialPowerOn();
-void auxSerialPowerOff();
-#if defined(AUX_SERIAL_PWR_GPIO)
-#define AUX_SERIAL_POWER_ON()             auxSerialPowerOn()
-#define AUX_SERIAL_POWER_OFF()            auxSerialPowerOff()
-#else
-#define AUX_SERIAL_POWER_ON()
-#define AUX_SERIAL_POWER_OFF()
-#endif
-#endif
 
-// Aux2 serial port driver
-#if defined(AUX2_SERIAL)
-#define aux2SerialTelemetryInit(protocol) aux2SerialInit(UART_MODE_TELEMETRY, protocol)
-void aux2SerialPowerOn();
-void aux2SerialPowerOff();
-#if defined(AUX2_SERIAL_PWR_GPIO)
-#define AUX2_SERIAL_POWER_ON()            aux2SerialPowerOn()
-#define AUX2_SERIAL_POWER_OFF()           aux2SerialPowerOff()
-#else
-#define AUX2_SERIAL_POWER_ON()
-#define AUX2_SERIAL_POWER_OFF()
-#endif
-#endif
+const etx_serial_port_t* auxSerialGetPort(int port_nr);
 
 // Haptic driver
 void hapticInit();
@@ -711,14 +685,4 @@ void bluetoothWriteWakeup();
 uint8_t bluetoothIsWriting();
 void bluetoothDisable();
 
-#if defined(__cplusplus)
-#include "fifo.h"
-#include "dmafifo.h"
-extern DMAFifo<512> telemetryFifo;
-typedef DMAFifo<32> AuxSerialRxFifo;
-extern AuxSerialRxFifo auxSerialRxFifo;
-extern AuxSerialRxFifo aux2SerialRxFifo;
-extern volatile uint32_t externalModulePort;
-#endif
-
 #endif // _BOARD_H_
diff --git a/radio/src/targets/horus/flyskyHallStick_driver.cpp b/radio/src/targets/horus/flyskyHallStick_driver.cpp
index 43ae99448..a2889b2b5 100644
--- a/radio/src/targets/horus/flyskyHallStick_driver.cpp
+++ b/radio/src/targets/horus/flyskyHallStick_driver.cpp
@@ -22,6 +22,9 @@
 #include "opentx.h"
 #include "flyskyHallStick_driver.h"
 
+#include "fifo.h"
+#include "dmafifo.h"
+
 DMAFifo<HALLSTICK_BUFF_SIZE> hallDMAFifo __DMA (FLYSKY_HALL_DMA_Stream_RX);
 Fifo<uint8_t, HALLSTICK_BUFF_SIZE> hallStickTxFifo;
 unsigned char HallCmd[264] __DMA;
diff --git a/radio/src/targets/horus/telemetry_driver.cpp b/radio/src/targets/horus/telemetry_driver.cpp
index f04de051d..618b07873 100644
--- a/radio/src/targets/horus/telemetry_driver.cpp
+++ b/radio/src/targets/horus/telemetry_driver.cpp
@@ -21,6 +21,9 @@
 
 #include "opentx.h"
 
+#include "fifo.h"
+#include "dmafifo.h"
+
 Fifo<uint8_t, TELEMETRY_FIFO_SIZE> telemetryNoDMAFifo;
 uint32_t telemetryErrors = 0;
 
@@ -415,7 +418,7 @@ extern "C" void TELEMETRY_TIMER_IRQHandler()
 }
 
 // TODO we should have telemetry in an higher layer, functions above should move to a sport_driver.cpp
-bool telemetryGetByte(uint8_t * byte)
+bool sportGetByte(uint8_t * byte)
 {
 #if defined(PCBX12S)
   if (telemetryFifoMode & TELEMETRY_SERIAL_WITHOUT_DMA)
diff --git a/radio/src/targets/horus/trainer_driver.cpp b/radio/src/targets/horus/trainer_driver.cpp
index cf3355f2c..6f49e02e7 100644
--- a/radio/src/targets/horus/trainer_driver.cpp
+++ b/radio/src/targets/horus/trainer_driver.cpp
@@ -142,22 +142,3 @@ extern "C" void TRAINER_TIMER_IRQHandler()
     }
   }
 }
-
-int sbusGetByte(uint8_t * byte)
-{
-  switch (currentTrainerMode) {
-#if defined(AUX_SERIAL) || defined(AUX2_SERIAL)
-    case TRAINER_MODE_MASTER_BATTERY_COMPARTMENT:
-#if defined(AUX_SERIAL)
-      if (auxSerialMode == UART_MODE_SBUS_TRAINER)
-        return auxSerialRxFifo.pop(*byte);
-#endif
-#if defined(AUX2_SERIAL)
-      if (aux2SerialMode == UART_MODE_SBUS_TRAINER)
-        return aux2SerialRxFifo.pop(*byte);
-#endif
-#endif
-    default:
-      return false;
-  }
-}
diff --git a/radio/src/targets/nv14/board.cpp b/radio/src/targets/nv14/board.cpp
index 0eeea7b87..bcede129f 100644
--- a/radio/src/targets/nv14/board.cpp
+++ b/radio/src/targets/nv14/board.cpp
@@ -23,8 +23,8 @@
 #include "touch.h"
 
 #include "hal/adc_driver.h"
-#include "../common/arm/stm32/stm32_hal_adc.h"
-#include "../common/arm/stm32/timers_driver.h"
+#include "stm32_hal_adc.h"
+#include "timers_driver.h"
 
 #if defined(__cplusplus) && !defined(SIMU)
 extern "C" {
@@ -242,3 +242,8 @@ void boardOff()
 
   }
 }
+
+const etx_serial_port_t* auxSerialGetPort(int port_nr)
+{
+  return nullptr;
+}
diff --git a/radio/src/targets/nv14/board.h b/radio/src/targets/nv14/board.h
index 41c63a037..a9b730e95 100644
--- a/radio/src/targets/nv14/board.h
+++ b/radio/src/targets/nv14/board.h
@@ -26,6 +26,7 @@
 #include "opentx_constants.h"
 #include "board_common.h"
 #include "hal.h"
+#include "hal/serial_port.h"
 
 #if !defined(LUA_EXPORT_GENERATION)
 #include "stm32f4xx_sdio.h"
@@ -390,9 +391,8 @@ bool pwrPressed();
 #endif
 uint32_t pwrPressedDuration();;
   
-#define AUX_SERIAL_POWER_ON()
-#define AUX_SERIAL_POWER_OFF()
-
+const etx_serial_port_t* auxSerialGetPort(int port_nr);
+  
 // LCD driver
 #define LCD_W                           320
 #define LCD_H                           480
@@ -483,7 +483,7 @@ void telemetryPortInit(uint32_t baudrate, uint8_t mode);
 void telemetryPortSetDirectionOutput();
 void telemetryPortSetDirectionInput();
 void sportSendBuffer(const uint8_t * buffer, uint32_t count);
-bool telemetryGetByte(uint8_t * byte);
+bool sportGetByte(uint8_t * byte);
 void telemetryClearFifo();
 void sportSendByte(uint8_t byte);
 extern uint32_t telemetryErrors;
@@ -507,27 +507,10 @@ void hapticOn(uint32_t pwmPercent);
 //#define AUX_SERIAL
 #define DEBUG_BAUDRATE                  115200
 #define LUA_DEFAULT_BAUDRATE            115200
-#define auxSerialTelemetryInit(protocol) auxSerialInit(UART_MODE_TELEMETRY, protocol)
-
-#if defined(AUX_SERIAL_PWR_GPIO)
-#define AUX_SERIAL_POWER_ON()            auxSerialPowerOn()
-#define AUX_SERIAL__POWER_OFF()          auxSerialPowerOff()
-#else
-#define AUX_SERIAL_POWER_ON()
-#define AUX_SERIAL__POWER_OFF()
-#endif
 
 extern uint8_t currentTrainerMode;
 void checkTrainerSettings();
 
-#if defined(__cplusplus)
-#include "fifo.h"
-#include "dmafifo.h"
-extern DMAFifo<512> telemetryFifo;
-typedef Fifo<uint8_t, 32> AuxSerialRxFifo;
-extern AuxSerialRxFifo auxSerialRxFifo;
-#endif
-
 // Touch panel driver
 bool touchPanelEventOccured();
 struct TouchState touchPanelRead();
diff --git a/radio/src/targets/nv14/telemetry_driver.cpp b/radio/src/targets/nv14/telemetry_driver.cpp
index 53936f914..b94ce7abc 100644
--- a/radio/src/targets/nv14/telemetry_driver.cpp
+++ b/radio/src/targets/nv14/telemetry_driver.cpp
@@ -215,7 +215,7 @@ extern "C" void TELEMETRY_USART_IRQHandler(void)
 }
 
 // TODO we should have telemetry in an higher layer, functions above should move to a sport_driver.cpp
-bool telemetryGetByte(uint8_t * byte)
+bool sportGetByte(uint8_t * byte)
 {
 #if defined(PCBX12S)
   if (telemetryFifoMode & TELEMETRY_SERIAL_WITHOUT_DMA)
diff --git a/radio/src/targets/simu/module_drivers.cpp b/radio/src/targets/simu/module_drivers.cpp
index ec3bf5d96..d369d3324 100644
--- a/radio/src/targets/simu/module_drivers.cpp
+++ b/radio/src/targets/simu/module_drivers.cpp
@@ -63,11 +63,12 @@ void stop_trainer_module_sbus() {}
 void init_intmodule_heartbeat() {}
 void stop_intmodule_heartbeat() {}
 
-static void init(const etx_serial_init*) {}
-static void deinit() {}
-static void sendByte(uint8_t) {}
-static void sendBuffer(const uint8_t*, uint8_t) {}
-static void waitForTxCompleted() {}
+static void* init(const etx_serial_init*) { return nullptr; }
+static void deinit(void*) {}
+static void sendByte(void*, uint8_t) {}
+static void sendBuffer(void*, const uint8_t*, uint8_t) {}
+static void waitForTxCompleted(void*) {}
+static int getByte(void*,uint8_t*) { return -1; }
 
 const etx_serial_driver_t IntmoduleSerialDriver = {
     .init = init,
@@ -75,6 +76,7 @@ const etx_serial_driver_t IntmoduleSerialDriver = {
     .sendByte = sendByte,
     .sendBuffer = sendBuffer,
     .waitForTxCompleted = waitForTxCompleted,
+    .getByte = getByte,
     .setReceiveCb = nullptr,
     .setOnErrorCb = nullptr,
 };
@@ -85,6 +87,7 @@ const etx_serial_driver_t ExtmoduleSerialDriver = {
     .sendByte = sendByte,
     .sendBuffer = sendBuffer,
     .waitForTxCompleted = waitForTxCompleted,
+    .getByte = getByte,
     .setReceiveCb = nullptr,
     .setOnErrorCb = nullptr,
 };
diff --git a/radio/src/targets/simu/simpgmspace.cpp b/radio/src/targets/simu/simpgmspace.cpp
index 4b2f60aae..d4a60c29c 100644
--- a/radio/src/targets/simu/simpgmspace.cpp
+++ b/radio/src/targets/simu/simpgmspace.cpp
@@ -429,7 +429,7 @@ void telemetryPortInit(uint32_t baudrate, uint8_t mode)
 {
 }
 
-bool telemetryGetByte(uint8_t * byte)
+bool sportGetByte(uint8_t * byte)
 {
   return false;
 }
@@ -732,6 +732,7 @@ void disableSpeaker()
 }
 #endif
 
+int trainerModuleSbusGetByte(unsigned char*) { return 0; }
 
 void rtcInit()
 {
@@ -751,60 +752,7 @@ void usbSerialPutc(uint8_t c)
 }
 #endif
 
-#if defined(AUX_SERIAL)
-#if defined(AUX_SERIAL_DMA_Stream_RX)
-AuxSerialRxFifo auxSerialRxFifo(nullptr);
-#else
-AuxSerialRxFifo auxSerialRxFifo;
-#endif
-uint8_t auxSerialMode;
-
-void auxSerialSetup(unsigned int baudrate, bool dma, uint8_t length, uint8_t parity, uint8_t stop)
-{
-}
-
-void auxSerialInit(unsigned int mode, unsigned int protocol)
-{
-}
-
-void auxSerialPutc(uint8_t c)
-{
-}
-
-void auxSerialSbusInit()
-{
-}
-
-void auxSerialStop()
-{
-}
-#endif
-
-#if defined(AUX2_SERIAL)
-AuxSerialRxFifo aux2SerialRxFifo(nullptr);
-uint8_t aux2SerialMode;
-
-void aux2SerialSetup(unsigned int baudrate, bool dma, uint8_t length, uint8_t parity, uint8_t stop)
-{
-}
-
-void aux2SerialInit(unsigned int mode, unsigned int protocol)
-{
-}
-
-void aux2SerialPutc(uint8_t c)
-{
-}
-
-void aux2SerialSbusInit()
-{
-}
-
-void aux2SerialStop()
-{
-}
-#endif
-
+const etx_serial_port_t* auxSerialGetPort(int port_nr) { return nullptr; }
 
 #if defined(HARDWARE_TOUCH)
 struct TouchState simTouchState = {};
diff --git a/radio/src/targets/taranis/CMakeLists.txt b/radio/src/targets/taranis/CMakeLists.txt
index f4fca7089..564ba8a9b 100644
--- a/radio/src/targets/taranis/CMakeLists.txt
+++ b/radio/src/targets/taranis/CMakeLists.txt
@@ -31,7 +31,7 @@ if(PCB STREQUAL X9E)
     top_lcd_driver.cpp
     startup_stm32f40_41xxx.s
     )
-  set(AUX_SERIAL_DRIVER ../common/arm/stm32/aux_serial_driver.cpp)
+  set(AUX_SERIAL ON)
   if(STICKS STREQUAL HORUS)
     add_definitions(-DHORUS_STICKS)
   endif()
@@ -90,7 +90,7 @@ elseif(PCB STREQUAL X9D+)
     set(CPU_TYPE_FULL STM32F205xE)  # for size report
     add_definitions(-DSTM32F205xx)
     set(LINKER_SCRIPT targets/taranis/stm32f2_flash.ld)
-    set(AUX_SERIAL_DRIVER ../common/arm/stm32/aux_serial_driver.cpp)
+    set(AUX_SERIAL ON)
     set(STATUS_LEDS NO)
   endif()
 elseif(PCB STREQUAL X9D)
@@ -110,7 +110,7 @@ elseif(PCB STREQUAL X9D)
   set(BITMAPS_TARGET taranis_bitmaps)
   set(FONTS_TARGET taranis_fonts)
   set(LCD_DRIVER lcd_driver_aspi.cpp)
-  set(AUX_SERIAL_DRIVER ../common/arm/stm32/aux_serial_driver.cpp)
+  set(AUX_SERIAL ON)
   set(GVAR_SCREEN model_gvars.cpp)
   set(STATUS_LEDS NO)
   add_definitions(-DMANUFACTURER_FRSKY)
@@ -207,7 +207,7 @@ elseif(PCB STREQUAL X7)
     set(LUA_EXPORT lua_export_zorro)
     set(BLUETOOTH NO)
     set(USB_CHARGER YES)
-    set(AUX_SERIAL_DRIVER ../common/arm/stm32/aux_serial_driver.cpp)
+    set(AUX_SERIAL ON)
     add_definitions(-DRADIO_ZORRO)
     add_definitions(-DEEPROM_VARIANT=0x4006)
     add_definitions(-DMANUFACTURER_RADIOMASTER)
diff --git a/radio/src/targets/taranis/board.cpp b/radio/src/targets/taranis/board.cpp
index 5d4ab4ecc..bcc4a1658 100644
--- a/radio/src/targets/taranis/board.cpp
+++ b/radio/src/targets/taranis/board.cpp
@@ -26,6 +26,10 @@
 
 #include "../common/arm/stm32/timers_driver.h"
 
+#if defined(AUX_SERIAL)
+#include "aux_serial_driver.h"
+#endif
+
 #if defined(__cplusplus)
 extern "C" {
 #endif
@@ -223,10 +227,7 @@ void boardInit()
   i2cInit();
   usbInit();
 
-#if defined(DEBUG) && defined(AUX_SERIAL_GPIO)
-  auxSerialInit(0, 0); // default serial mode (None if DEBUG not defined)
-  TRACE("\nTaranis board started :)");
-#endif
+  initSerialPorts();
 
 #if defined(HAPTIC)
   hapticInit();
@@ -415,3 +416,26 @@ void initJackDetect(void)
   GPIO_Init(JACK_DETECT_GPIO, &GPIO_InitStructure);
 }
 #endif
+
+#if defined(AUX_SERIAL)
+const etx_serial_port_t auxSerialPort = {
+  &AuxSerialDriver,
+  nullptr
+};
+#define AUX_SERIAL_PORT &auxSerialPort
+#else
+#define AUX_SERIAL_PORT nullptr
+#endif
+
+#define AUX2_SERIAL_PORT nullptr
+
+static const etx_serial_port_t* serialPorts[MAX_AUX_SERIAL] = {
+  AUX_SERIAL_PORT,
+  AUX2_SERIAL_PORT,
+};
+
+const etx_serial_port_t* auxSerialGetPort(int port_nr)
+{
+  if (port_nr >= MAX_AUX_SERIAL) return nullptr;
+  return serialPorts[port_nr];
+}
diff --git a/radio/src/targets/taranis/board.h b/radio/src/targets/taranis/board.h
index a1d6d1f35..550bb9892 100644
--- a/radio/src/targets/taranis/board.h
+++ b/radio/src/targets/taranis/board.h
@@ -27,6 +27,7 @@
 #include "opentx_constants.h"
 #include "board_common.h"
 #include "hal.h"
+#include "hal/serial_port.h"
 
 #include "watchdog_driver.h"
 
@@ -164,26 +165,20 @@ uint32_t isBootloaderStart(const uint8_t * buffer);
   #define init_trainer_capture()
   #define stop_trainer_capture()
 #endif
+
 #if defined(TRAINER_MODULE_CPPM)
   void init_trainer_module_cppm();
   void stop_trainer_module_cppm();
-#else
-  #define init_trainer_module_cppm()
-  #define stop_trainer_module_cppm()
 #endif
+
 #if defined(TRAINER_MODULE_SBUS)
   void init_trainer_module_sbus();
   void stop_trainer_module_sbus();
-#else
-  #define init_trainer_module_sbus()
-  #define stop_trainer_module_sbus()
+  int trainerModuleSbusGetByte(uint8_t* byte);
 #endif
 
 void check_telemetry_exti();
 
-// SBUS
-int sbusGetByte(uint8_t * byte);
-
 // Keys driver
 enum EnumKeys
 {
@@ -775,7 +770,7 @@ void sportSendByte(uint8_t byte);
 void sportSendByteLoop(uint8_t byte);
 void sportStopSendByteLoop();
 void sportSendBuffer(const uint8_t * buffer, uint32_t count);
-bool telemetryGetByte(uint8_t * byte);
+bool sportGetByte(uint8_t * byte);
 void telemetryClearFifo();
 extern uint32_t telemetryErrors;
 
@@ -860,15 +855,10 @@ void hapticOff();
   void hapticOn();
 #endif
 
-// Aux serial port driver
-#if defined(AUX_SERIAL_GPIO)
 #define DEBUG_BAUDRATE                  115200
 #define LUA_DEFAULT_BAUDRATE            115200
-#define AUX_SERIAL
-#define auxSerialTelemetryInit(protocol) auxSerialInit(UART_MODE_TELEMETRY, protocol)
-#define AUX_SERIAL_POWER_ON()
-#define AUX_SERIAL_POWER_OFF()
-#endif
+
+const etx_serial_port_t* auxSerialGetPort(int port_nr);
 
 // BT driver
 #define BLUETOOTH_BOOTLOADER_BAUDRATE   230400
diff --git a/radio/src/targets/taranis/hal.h b/radio/src/targets/taranis/hal.h
index 3a0e81a79..61b3daa1c 100644
--- a/radio/src/targets/taranis/hal.h
+++ b/radio/src/targets/taranis/hal.h
@@ -1929,14 +1929,14 @@
   #define TRAINER_MODULE_CPPM_TIMER_IRQn          TRAINER_TIMER_IRQn
   #define TRAINER_MODULE_CPPM_GPIO_AF             GPIO_AF_TIM3
   // Trainer SBUS input on heartbeat pin
-  #define TRAINER_MODULE_SBUS
-  #define TRAINER_MODULE_SBUS_GPIO_AF             GPIO_AF_USART6
-  #define TRAINER_MODULE_SBUS_USART               USART6
-  #define TRAINER_MODULE_SBUS_GPIO                INTMODULE_HEARTBEAT_GPIO
-  #define TRAINER_MODULE_SBUS_GPIO_PIN            INTMODULE_HEARTBEAT_GPIO_PIN
-  #define TRAINER_MODULE_SBUS_GPIO_PinSource      INTMODULE_HEARTBEAT_EXTI_PinSource
-  #define TRAINER_MODULE_SBUS_DMA_STREAM          DMA2_Stream1
-  #define TRAINER_MODULE_SBUS_DMA_CHANNEL         DMA_Channel_5
+  // #define TRAINER_MODULE_SBUS
+  // #define TRAINER_MODULE_SBUS_GPIO_AF             GPIO_AF_USART6
+  // #define TRAINER_MODULE_SBUS_USART               USART6
+  // #define TRAINER_MODULE_SBUS_GPIO                INTMODULE_HEARTBEAT_GPIO
+  // #define TRAINER_MODULE_SBUS_GPIO_PIN            INTMODULE_HEARTBEAT_GPIO_PIN
+  // #define TRAINER_MODULE_SBUS_GPIO_PinSource      INTMODULE_HEARTBEAT_EXTI_PinSource
+  // #define TRAINER_MODULE_SBUS_DMA_STREAM          DMA2_Stream1
+  // #define TRAINER_MODULE_SBUS_DMA_CHANNEL         DMA_Channel_5
 #else
   // TODO: replace SBUS trainer with S.PORT pin
   #define TRAINER_MODULE_RCC_AHB1Periph           0
diff --git a/radio/src/targets/taranis/telemetry_driver.cpp b/radio/src/targets/taranis/telemetry_driver.cpp
index 8709dfbb6..f634c5b21 100644
--- a/radio/src/targets/taranis/telemetry_driver.cpp
+++ b/radio/src/targets/taranis/telemetry_driver.cpp
@@ -393,22 +393,12 @@ extern "C" void TELEMETRY_TIMER_IRQHandler()
   telemetryPortInvertedRxBit();
 }
 
-// TODO we should have telemetry in an higher layer, functions above should move to a sport_driver.cpp
-bool telemetryGetByte(uint8_t * byte)
+// TODO: we should have telemetry in an higher layer,
+//       functions above should move to a sport_driver.cpp
+//
+bool sportGetByte(uint8_t * byte)
 {
-#if defined(AUX_SERIAL)
-  if (telemetryProtocol == PROTOCOL_TELEMETRY_FRSKY_D_SECONDARY) {
-    if (auxSerialMode == UART_MODE_TELEMETRY)
-      return auxSerialRxFifo.pop(*byte);
-    else
-      return false;
-  }
-  else {
-    return telemetryFifo.pop(*byte);
-  }
-#else
   return telemetryFifo.pop(*byte);
-#endif
 }
 
 void telemetryClearFifo()
diff --git a/radio/src/targets/taranis/trainer_driver.cpp b/radio/src/targets/taranis/trainer_driver.cpp
index a78d9c906..919c38240 100644
--- a/radio/src/targets/taranis/trainer_driver.cpp
+++ b/radio/src/targets/taranis/trainer_driver.cpp
@@ -21,10 +21,6 @@
 
 #include "opentx.h"
 
-#if defined(TRAINER_MODULE_SBUS_USART)
-DMAFifo<32> trainerSbusFifo __DMA (TRAINER_MODULE_SBUS_DMA_STREAM);
-#endif
-
 void trainerSendNextFrame();
 
 #if defined(TRAINER_GPIO)
@@ -267,7 +263,11 @@ void stop_trainer_module_cppm()
 }
 #endif
 
+// TODO: use external module serial driver
 #if defined(TRAINER_MODULE_SBUS)
+
+static DMAFifo<32> trainerSbusFifo __DMA (TRAINER_MODULE_SBUS_DMA_STREAM);
+
 void init_trainer_module_sbus()
 {
   EXTERNAL_MODULE_ON();
@@ -328,22 +328,9 @@ void stop_trainer_module_sbus()
     EXTERNAL_MODULE_OFF();
   }
 }
-#endif
 
-#if defined(SBUS_TRAINER)
-int sbusGetByte(uint8_t * byte)
+int trainerModuleSbusGetByte(uint8_t* byte)
 {
-  switch (currentTrainerMode) {
-#if defined(TRAINER_MODULE_SBUS_USART)
-    case TRAINER_MODE_MASTER_SBUS_EXTERNAL_MODULE:
-      return trainerSbusFifo.pop(*byte);
-#endif
-#if defined(AUX_SERIAL_USART)
-    case TRAINER_MODE_MASTER_BATTERY_COMPARTMENT:
-      return auxSerialRxFifo.pop(*byte);
-#endif
-    default:
-      return false;
-  }
+  return trainerSbusFifo.pop(*byte);
 }
 #endif
diff --git a/radio/src/telemetry/crossfire.cpp b/radio/src/telemetry/crossfire.cpp
index 257a18faa..ef30d580f 100644
--- a/radio/src/telemetry/crossfire.cpp
+++ b/radio/src/telemetry/crossfire.cpp
@@ -293,17 +293,7 @@ void processCrossfireTelemetryData(uint8_t data, uint8_t module)
   uint8_t * rxBuffer = getTelemetryRxBuffer(module);
   uint8_t &rxBufferCount = getTelemetryRxBufferCount(module);
 
-#if defined(AUX_SERIAL)
-  if (g_eeGeneral.auxSerialMode == UART_MODE_TELEMETRY_MIRROR) {
-    auxSerialPutc(data);
-  }
-#endif
-
-#if defined(AUX2_SERIAL)
-  if (g_eeGeneral.aux2SerialMode == UART_MODE_TELEMETRY_MIRROR) {
-    aux2SerialPutc(data);
-  }
-#endif
+  telemetryMirrorSend(data);
 
   if (rxBufferCount == 0 && data != RADIO_ADDRESS && data != UART_SYNC) {
     TRACE("[XF] address 0x%02X error", data);
diff --git a/radio/src/telemetry/crossfire.h b/radio/src/telemetry/crossfire.h
index 59d9524a5..044cd3415 100644
--- a/radio/src/telemetry/crossfire.h
+++ b/radio/src/telemetry/crossfire.h
@@ -116,6 +116,7 @@ const uint8_t CROSSFIRE_FRAME_PERIODS[] = {
   4,
   4,
   4,
+  4,
 };
 #if SPORT_MAX_BAUDRATE < 400000
   // index 0 (115200) is the default 0 value
diff --git a/radio/src/telemetry/frsky.cpp b/radio/src/telemetry/frsky.cpp
index 6f0b0e6b1..a2d1e798e 100644
--- a/radio/src/telemetry/frsky.cpp
+++ b/radio/src/telemetry/frsky.cpp
@@ -24,17 +24,7 @@
 
 void processFrskyTelemetryData(uint8_t data)
 {
-
-#if defined(AUX_SERIAL)
-  if (g_eeGeneral.auxSerialMode == UART_MODE_TELEMETRY_MIRROR) {
-    auxSerialPutc(data);
-  }
-#endif
-#if defined(AUX2_SERIAL)
-  if (g_eeGeneral.aux2SerialMode == UART_MODE_TELEMETRY_MIRROR) {
-    aux2SerialPutc(data);
-  }
-#endif
+  telemetryMirrorSend(data);
 
   if (pushFrskyTelemetryData(data)) {
     if (IS_FRSKY_SPORT_PROTOCOL()) {
diff --git a/radio/src/telemetry/ghost.cpp b/radio/src/telemetry/ghost.cpp
index 525ea3642..879eeaaf0 100755
--- a/radio/src/telemetry/ghost.cpp
+++ b/radio/src/telemetry/ghost.cpp
@@ -322,17 +322,7 @@ void processGhostTelemetryFrame()
 
 void processGhostTelemetryData(uint8_t data)
 {
-#if defined(AUX_SERIAL)
-  if (g_eeGeneral.auxSerialMode == UART_MODE_TELEMETRY_MIRROR) {
-    auxSerialPutc(data);
-  }
-#endif
-
-#if defined(AUX2_SERIAL)
-  if (g_eeGeneral.aux2SerialMode == UART_MODE_TELEMETRY_MIRROR) {
-    aux2SerialPutc(data);
-  }
-#endif
+  telemetryMirrorSend(data);
 
   if (telemetryRxBufferCount == 0 && data != GHST_ADDR_RADIO) {
     TRACE("[GH] address 0x%02X error", data);
diff --git a/radio/src/telemetry/multi.cpp b/radio/src/telemetry/multi.cpp
index c43edfd5f..c4f3a1c6f 100644
--- a/radio/src/telemetry/multi.cpp
+++ b/radio/src/telemetry/multi.cpp
@@ -257,7 +257,7 @@ static void processMultiSyncPacket(const uint8_t * data, uint8_t module)
 
   status.update(refreshRate, inputLag);
 #if defined(DEBUG)
-  serialPrint("MP ADJ: R %d, L %04d", refreshRate, inputLag);
+  dbgSerialPrint("MP ADJ: R %d, L %04d", refreshRate, inputLag);
 #endif
 }
 
@@ -351,18 +351,8 @@ static void processMultiTelemetryPaket(const uint8_t * packet, uint8_t module)
   uint8_t len = packet[1];
   const uint8_t * data = packet + 2;
 
-#if defined(AUX_SERIAL)
-  if (g_eeGeneral.auxSerialMode == UART_MODE_TELEMETRY_MIRROR) {
-    for (uint8_t c = 0; c < len + 2; c++)
-      auxSerialPutc(packet[c]);
-  }
-#endif
-#if defined(AUX2_SERIAL)
-  if (g_eeGeneral.aux2SerialMode == UART_MODE_TELEMETRY_MIRROR) {
-    for (uint8_t c = 0; c < len + 2; c++)
-      aux2SerialPutc(packet[c]);
-  }
-#endif
+  for (uint8_t c = 0; c < len + 2; c++)
+    telemetryMirrorSend(packet[c]);
 
   // Switch type
   switch (type) {
diff --git a/radio/src/telemetry/telemetry.cpp b/radio/src/telemetry/telemetry.cpp
index bc65bc6a7..670d94c5d 100644
--- a/radio/src/telemetry/telemetry.cpp
+++ b/radio/src/telemetry/telemetry.cpp
@@ -42,8 +42,8 @@ TelemetryData telemetryData;
 uint8_t telemetryProtocol = 255;
 
 #if defined(INTERNAL_MODULE_SERIAL_TELEMETRY)
-uint8_t intTelemetryRxBuffer[TELEMETRY_RX_PACKET_SIZE];
-uint8_t intTelemetryRxBufferCount;
+static uint8_t intTelemetryRxBuffer[TELEMETRY_RX_PACKET_SIZE];
+static uint8_t intTelemetryRxBufferCount;
 #endif
 
 uint8_t * getTelemetryRxBuffer(uint8_t moduleIdx)
@@ -64,6 +64,48 @@ uint8_t &getTelemetryRxBufferCount(uint8_t moduleIdx)
   return telemetryRxBufferCount;
 }
 
+static int (*_telemetryGetByte)(void*, uint8_t*) = nullptr;
+static void* _telemetryGetByteCtx = nullptr;
+
+void telemetrySetGetByte(void* ctx, int (*fct)(void*, uint8_t*))
+{
+  _telemetryGetByte = nullptr;
+  _telemetryGetByteCtx = ctx;
+  _telemetryGetByte = fct;
+}
+
+static bool telemetryGetByte(uint8_t* data)
+{
+  auto _getByte = _telemetryGetByte;
+  auto _ctx = _telemetryGetByteCtx;
+
+  if (_getByte) {
+    return _getByte(_ctx, data);
+  }
+
+  return sportGetByte(data);
+}
+
+static void (*telemetryMirrorSendByte)(void*, uint8_t) = nullptr;
+static void* telemetryMirrorSendByteCtx = nullptr;
+
+void telemetrySetMirrorCb(void* ctx, void (*fct)(void*, uint8_t))
+{
+  telemetryMirrorSendByte = nullptr;
+  telemetryMirrorSendByteCtx = ctx;
+  telemetryMirrorSendByte = fct;
+}
+
+void telemetryMirrorSend(uint8_t data)
+{
+  auto _sendByte = telemetryMirrorSendByte;
+  auto _ctx = telemetryMirrorSendByteCtx;
+
+  if (_sendByte) {
+    _sendByte(_ctx, data);
+  }
+}
+
 void processTelemetryData(uint8_t data)
 {
 #if defined(CROSSFIRE)
@@ -427,7 +469,8 @@ void telemetryInit(uint8_t protocol)
 #if defined(AUX_SERIAL)
   else if (protocol == PROTOCOL_TELEMETRY_FRSKY_D_SECONDARY) {
     telemetryPortInit(0, TELEMETRY_SERIAL_DEFAULT);
-    auxSerialTelemetryInit(PROTOCOL_TELEMETRY_FRSKY_D_SECONDARY);
+    // Note: this is done in initSerialPorts()
+    //auxSerialTelemetryInit(PROTOCOL_TELEMETRY_FRSKY_D_SECONDARY);
   }
 #endif
 
diff --git a/radio/src/telemetry/telemetry.h b/radio/src/telemetry/telemetry.h
index d5edb5386..a3c2c84f3 100644
--- a/radio/src/telemetry/telemetry.h
+++ b/radio/src/telemetry/telemetry.h
@@ -75,10 +75,17 @@ constexpr uint8_t TELEMETRY_TIMEOUT10ms = 100; // 1 second
 extern uint8_t telemetryRxBuffer[TELEMETRY_RX_PACKET_SIZE];
 extern uint8_t telemetryRxBufferCount;
 
-//TODO: use module scoped buffers instead
 uint8_t* getTelemetryRxBuffer(uint8_t moduleIdx);
 uint8_t& getTelemetryRxBufferCount(uint8_t moduleIdx);
 
+// Set alternative telemetry input
+void telemetrySetGetByte(void* ctx, int (*fct)(void*, uint8_t*));
+
+// Set telemetry mirror callback
+void telemetrySetMirrorCb(void* ctx, void (*fct)(void*, uint8_t));
+
+// Mirror telemetry byte
+void telemetryMirrorSend(uint8_t data);
 
 #define TELEMETRY_AVERAGE_COUNT        3
 
diff --git a/radio/src/trainer.cpp b/radio/src/trainer.cpp
index 4840ebc9c..73cd2504d 100644
--- a/radio/src/trainer.cpp
+++ b/radio/src/trainer.cpp
@@ -69,20 +69,14 @@ void stopTrainer()
 
 #if defined(TRAINER_MODULE_SBUS)
     case TRAINER_MODE_MASTER_SBUS_EXTERNAL_MODULE:
+      sbusSetGetByte(nullptr);
       stop_trainer_module_sbus();
       break;
 #endif
 
 #if defined(TRAINER_BATTERY_COMPARTMENT)
     case TRAINER_MODE_MASTER_BATTERY_COMPARTMENT:
-#if defined(AUX_SERIAL)
-      if (g_eeGeneral.auxSerialMode == UART_MODE_SBUS_TRAINER)
-        auxSerialStop();
-#endif
-#if defined(AUX2_SERIAL)
-      if (g_eeGeneral.aux2SerialMode == UART_MODE_SBUS_TRAINER)
-        aux2SerialStop();
-#endif
+      sbusSetGetByte(nullptr);
       break;
 #endif
   }
@@ -115,26 +109,14 @@ void checkTrainerSettings()
 #if defined(TRAINER_MODULE_SBUS)
       case TRAINER_MODE_MASTER_SBUS_EXTERNAL_MODULE:
         init_trainer_module_sbus();
+        sbusSetGetByte(trainerModuleSbusGetByte);
         break;
 #endif
 
 #if defined(TRAINER_BATTERY_COMPARTMENT)
       case TRAINER_MODE_MASTER_BATTERY_COMPARTMENT:
-#if defined(AUX_SERIAL)
-        if (g_eeGeneral.auxSerialMode == UART_MODE_SBUS_TRAINER) {
-          auxSerialSbusInit();
-          break;
-        }
-#endif
-
-#if defined(AUX2_SERIAL)
-        if (g_eeGeneral.aux2SerialMode == UART_MODE_SBUS_TRAINER) {
-          aux2SerialSbusInit();
-          break;
-        }
-#endif
-
-        // no break
+        sbusSetGetByte(sbusAuxGetByte);
+        break;
 #endif
 
       case TRAINER_MODE_MASTER_TRAINER_JACK: