diff --git a/radio/src/gui/128x64/model_setup.cpp b/radio/src/gui/128x64/model_setup.cpp
index 1a694a370..8e28cdb8a 100644
--- a/radio/src/gui/128x64/model_setup.cpp
+++ b/radio/src/gui/128x64/model_setup.cpp
@@ -1670,6 +1670,7 @@ void menuModelSetup(event_t event)
 
       }
       break;
+
 #if !defined(PCBXLITE)
       case ITEM_MODEL_EXTERNAL_MODULE_FREQ:
       {
diff --git a/radio/src/io/frsky_device_firmware_update.cpp b/radio/src/io/frsky_device_firmware_update.cpp
index 973c6d8dc..c2bb0adf1 100644
--- a/radio/src/io/frsky_device_firmware_update.cpp
+++ b/radio/src/io/frsky_device_firmware_update.cpp
@@ -73,7 +73,7 @@ void DeviceFirmwareUpdate::startup()
   switch(module) {
     case INTERNAL_MODULE:
 #if defined(INTMODULE_USART)
-      intmoduleSerialStart(57600);
+      intmoduleSerialStart(57600, true);
       break;
 #endif
 
diff --git a/radio/src/pulses/pulses.cpp b/radio/src/pulses/pulses.cpp
index eb8325a47..846161850 100755
--- a/radio/src/pulses/pulses.cpp
+++ b/radio/src/pulses/pulses.cpp
@@ -209,11 +209,7 @@ void setupPulsesPXXInternalModule()
 
 void setupPulsesPXXExternalModule()
 {
-#if defined(EXTMODULE_USART)
-  extmodulePulsesData.pxx_uart.setupFrame(EXTERNAL_MODULE);
-#elif !defined(INTMODULE_USART) && !defined(EXTMODULE_USART)
   extmodulePulsesData.pxx.setupFrame(EXTERNAL_MODULE);
-#endif
 }
 #endif
 
diff --git a/radio/src/pulses/pulses.h b/radio/src/pulses/pulses.h
index 086b00e42..61b46ee64 100644
--- a/radio/src/pulses/pulses.h
+++ b/radio/src/pulses/pulses.h
@@ -152,12 +152,9 @@ union InternalModulePulsesData {
 
 union ExternalModulePulsesData {
 #if defined(PXX1)
-  #if defined(INTMODULE_USART) || defined(EXTMODULE_USART)
-    UartPxx1Pulses pxx_uart;
-  #endif
   #if defined(PPM_PIN_SERIAL)
     SerialPxx1Pulses pxx;
-  #elif !defined(INTMODULE_USART) || !defined(EXTMODULE_USART)
+  #else
     PwmPxx1Pulses pxx;
   #endif
 #endif
diff --git a/radio/src/pulses/pxx1.cpp b/radio/src/pulses/pxx1.cpp
index 568f9b38b..37d53e771 100644
--- a/radio/src/pulses/pxx1.cpp
+++ b/radio/src/pulses/pxx1.cpp
@@ -22,38 +22,38 @@
 #include "pulses/pxx1.h"
 
 const uint16_t Pxx1CrcMixin::CRCTable[] = {
-        0x0000,0x1189,0x2312,0x329b,0x4624,0x57ad,0x6536,0x74bf,
-        0x8c48,0x9dc1,0xaf5a,0xbed3,0xca6c,0xdbe5,0xe97e,0xf8f7,
-        0x1081,0x0108,0x3393,0x221a,0x56a5,0x472c,0x75b7,0x643e,
-        0x9cc9,0x8d40,0xbfdb,0xae52,0xdaed,0xcb64,0xf9ff,0xe876,
-        0x2102,0x308b,0x0210,0x1399,0x6726,0x76af,0x4434,0x55bd,
-        0xad4a,0xbcc3,0x8e58,0x9fd1,0xeb6e,0xfae7,0xc87c,0xd9f5,
-        0x3183,0x200a,0x1291,0x0318,0x77a7,0x662e,0x54b5,0x453c,
-        0xbdcb,0xac42,0x9ed9,0x8f50,0xfbef,0xea66,0xd8fd,0xc974,
-        0x4204,0x538d,0x6116,0x709f,0x0420,0x15a9,0x2732,0x36bb,
-        0xce4c,0xdfc5,0xed5e,0xfcd7,0x8868,0x99e1,0xab7a,0xbaf3,
-        0x5285,0x430c,0x7197,0x601e,0x14a1,0x0528,0x37b3,0x263a,
-        0xdecd,0xcf44,0xfddf,0xec56,0x98e9,0x8960,0xbbfb,0xaa72,
-        0x6306,0x728f,0x4014,0x519d,0x2522,0x34ab,0x0630,0x17b9,
-        0xef4e,0xfec7,0xcc5c,0xddd5,0xa96a,0xb8e3,0x8a78,0x9bf1,
-        0x7387,0x620e,0x5095,0x411c,0x35a3,0x242a,0x16b1,0x0738,
-        0xffcf,0xee46,0xdcdd,0xcd54,0xb9eb,0xa862,0x9af9,0x8b70,
-        0x8408,0x9581,0xa71a,0xb693,0xc22c,0xd3a5,0xe13e,0xf0b7,
-        0x0840,0x19c9,0x2b52,0x3adb,0x4e64,0x5fed,0x6d76,0x7cff,
-        0x9489,0x8500,0xb79b,0xa612,0xd2ad,0xc324,0xf1bf,0xe036,
-        0x18c1,0x0948,0x3bd3,0x2a5a,0x5ee5,0x4f6c,0x7df7,0x6c7e,
-        0xa50a,0xb483,0x8618,0x9791,0xe32e,0xf2a7,0xc03c,0xd1b5,
-        0x2942,0x38cb,0x0a50,0x1bd9,0x6f66,0x7eef,0x4c74,0x5dfd,
-        0xb58b,0xa402,0x9699,0x8710,0xf3af,0xe226,0xd0bd,0xc134,
-        0x39c3,0x284a,0x1ad1,0x0b58,0x7fe7,0x6e6e,0x5cf5,0x4d7c,
-        0xc60c,0xd785,0xe51e,0xf497,0x8028,0x91a1,0xa33a,0xb2b3,
-        0x4a44,0x5bcd,0x6956,0x78df,0x0c60,0x1de9,0x2f72,0x3efb,
-        0xd68d,0xc704,0xf59f,0xe416,0x90a9,0x8120,0xb3bb,0xa232,
-        0x5ac5,0x4b4c,0x79d7,0x685e,0x1ce1,0x0d68,0x3ff3,0x2e7a,
-        0xe70e,0xf687,0xc41c,0xd595,0xa12a,0xb0a3,0x8238,0x93b1,
-        0x6b46,0x7acf,0x4854,0x59dd,0x2d62,0x3ceb,0x0e70,0x1ff9,
-        0xf78f,0xe606,0xd49d,0xc514,0xb1ab,0xa022,0x92b9,0x8330,
-        0x7bc7,0x6a4e,0x58d5,0x495c,0x3de3,0x2c6a,0x1ef1,0x0f78
+  0x0000,0x1189,0x2312,0x329b,0x4624,0x57ad,0x6536,0x74bf,
+  0x8c48,0x9dc1,0xaf5a,0xbed3,0xca6c,0xdbe5,0xe97e,0xf8f7,
+  0x1081,0x0108,0x3393,0x221a,0x56a5,0x472c,0x75b7,0x643e,
+  0x9cc9,0x8d40,0xbfdb,0xae52,0xdaed,0xcb64,0xf9ff,0xe876,
+  0x2102,0x308b,0x0210,0x1399,0x6726,0x76af,0x4434,0x55bd,
+  0xad4a,0xbcc3,0x8e58,0x9fd1,0xeb6e,0xfae7,0xc87c,0xd9f5,
+  0x3183,0x200a,0x1291,0x0318,0x77a7,0x662e,0x54b5,0x453c,
+  0xbdcb,0xac42,0x9ed9,0x8f50,0xfbef,0xea66,0xd8fd,0xc974,
+  0x4204,0x538d,0x6116,0x709f,0x0420,0x15a9,0x2732,0x36bb,
+  0xce4c,0xdfc5,0xed5e,0xfcd7,0x8868,0x99e1,0xab7a,0xbaf3,
+  0x5285,0x430c,0x7197,0x601e,0x14a1,0x0528,0x37b3,0x263a,
+  0xdecd,0xcf44,0xfddf,0xec56,0x98e9,0x8960,0xbbfb,0xaa72,
+  0x6306,0x728f,0x4014,0x519d,0x2522,0x34ab,0x0630,0x17b9,
+  0xef4e,0xfec7,0xcc5c,0xddd5,0xa96a,0xb8e3,0x8a78,0x9bf1,
+  0x7387,0x620e,0x5095,0x411c,0x35a3,0x242a,0x16b1,0x0738,
+  0xffcf,0xee46,0xdcdd,0xcd54,0xb9eb,0xa862,0x9af9,0x8b70,
+  0x8408,0x9581,0xa71a,0xb693,0xc22c,0xd3a5,0xe13e,0xf0b7,
+  0x0840,0x19c9,0x2b52,0x3adb,0x4e64,0x5fed,0x6d76,0x7cff,
+  0x9489,0x8500,0xb79b,0xa612,0xd2ad,0xc324,0xf1bf,0xe036,
+  0x18c1,0x0948,0x3bd3,0x2a5a,0x5ee5,0x4f6c,0x7df7,0x6c7e,
+  0xa50a,0xb483,0x8618,0x9791,0xe32e,0xf2a7,0xc03c,0xd1b5,
+  0x2942,0x38cb,0x0a50,0x1bd9,0x6f66,0x7eef,0x4c74,0x5dfd,
+  0xb58b,0xa402,0x9699,0x8710,0xf3af,0xe226,0xd0bd,0xc134,
+  0x39c3,0x284a,0x1ad1,0x0b58,0x7fe7,0x6e6e,0x5cf5,0x4d7c,
+  0xc60c,0xd785,0xe51e,0xf497,0x8028,0x91a1,0xa33a,0xb2b3,
+  0x4a44,0x5bcd,0x6956,0x78df,0x0c60,0x1de9,0x2f72,0x3efb,
+  0xd68d,0xc704,0xf59f,0xe416,0x90a9,0x8120,0xb3bb,0xa232,
+  0x5ac5,0x4b4c,0x79d7,0x685e,0x1ce1,0x0d68,0x3ff3,0x2e7a,
+  0xe70e,0xf687,0xc41c,0xd595,0xa12a,0xb0a3,0x8238,0x93b1,
+  0x6b46,0x7acf,0x4854,0x59dd,0x2d62,0x3ceb,0x0e70,0x1ff9,
+  0xf78f,0xe606,0xd49d,0xc514,0xb1ab,0xa022,0x92b9,0x8330,
+  0x7bc7,0x6a4e,0x58d5,0x495c,0x3de3,0x2c6a,0x1ef1,0x0f78
 };
 
 template <class PxxTransport>
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 3cfdb2377..15d1f2f13 100755
--- a/radio/src/targets/common/arm/stm32/intmodule_serial_driver.cpp
+++ b/radio/src/targets/common/arm/stm32/intmodule_serial_driver.cpp
@@ -30,10 +30,10 @@ void intmoduleStop()
 
 void intmodulePxxStart()
 {
-  // shouldn't be used anymore
+  intmoduleSerialStart(INTMODULE_USART_PXX_BAUDRATE, false);
 }
 
-void intmoduleSerialStart(uint32_t baudrate)
+void intmoduleSerialStart(uint32_t baudrate, uint8_t rxEnable)
 {
   INTERNAL_MODULE_ON();
 
@@ -66,11 +66,12 @@ void intmoduleSerialStart(uint32_t baudrate)
   USART_Init(INTMODULE_USART, &USART_InitStructure);
   USART_Cmd(INTMODULE_USART, ENABLE);
 
-  intmoduleFifo.clear();
-
-  USART_ITConfig(INTMODULE_USART, USART_IT_RXNE, ENABLE);
-  NVIC_SetPriority(INTMODULE_USART_IRQn, 6);
-  NVIC_EnableIRQ(INTMODULE_USART_IRQn);
+  if (rxEnable) {
+    intmoduleFifo.clear();
+    USART_ITConfig(INTMODULE_USART, USART_IT_RXNE, ENABLE);
+    NVIC_SetPriority(INTMODULE_USART_IRQn, 6);
+    NVIC_EnableIRQ(INTMODULE_USART_IRQn);
+  }
 }
 
 #define USART_FLAG_ERRORS (USART_FLAG_ORE | USART_FLAG_NE | USART_FLAG_FE | USART_FLAG_PE)
@@ -119,10 +120,17 @@ void intmoduleSendBuffer(const uint8_t * data, uint8_t size)
 
 void intmoduleSendNextFrame()
 {
+  switch(moduleSettings[INTERNAL_MODULE].protocol) {
 #if defined(PXX2)
-  if (moduleSettings[INTERNAL_MODULE].protocol == PROTOCOL_CHANNELS_PXX2) {
-    intmoduleSendBuffer(intmodulePulsesData.pxx2.getData(), intmodulePulsesData.pxx2.getSize());
-  }
+    case PROTOCOL_CHANNELS_PXX2:
+      intmoduleSendBuffer(intmodulePulsesData.pxx2.getData(), intmodulePulsesData.pxx2.getSize());
+      break;
 #endif
+#if defined(PXX1)
+    case PROTOCOL_CHANNELS_PXX1:
+      intmoduleSendBuffer(intmodulePulsesData.pxx_uart.getData(), intmodulePulsesData.pxx_uart.getSize());
+      break;
+#endif
+  }
 }
 
diff --git a/radio/src/targets/horus/board.h b/radio/src/targets/horus/board.h
index 22809098a..4cb9c7a6e 100644
--- a/radio/src/targets/horus/board.h
+++ b/radio/src/targets/horus/board.h
@@ -212,6 +212,7 @@ void disable_pxx(uint8_t module);
 void init_pxx2(uint8_t module);
 void disable_pxx2(uint8_t module);
 void init_serial(uint8_t module, uint32_t baudrate, uint32_t period_half_us);
+void intmoduleSerialStart(uint32_t baudrate, uint8_t rxEnable);
 void disable_serial(uint8_t module);
 void intmoduleSendNextFrame();
 void extmoduleSendNextFrame();
diff --git a/radio/src/targets/horus/pulses_driver.cpp b/radio/src/targets/horus/pulses_driver.cpp
index a92b65679..f70189cec 100644
--- a/radio/src/targets/horus/pulses_driver.cpp
+++ b/radio/src/targets/horus/pulses_driver.cpp
@@ -22,7 +22,7 @@
 
 void intmoduleStop();
 void intmodulePxxStart();
-void intmoduleSerialStart(uint32_t baudrate);
+void intmoduleSerialStart(uint32_t baudrate, uint8_t rxEnable);
 
 void extmoduleStop();
 void extmodulePpmStart();
@@ -48,7 +48,7 @@ void disable_ppm(uint8_t module)
 void init_pxx2(uint8_t module)
 {
   if (module == INTERNAL_MODULE)
-    intmoduleSerialStart(INTMODULE_USART_PXX_BAUDRATE);
+    intmoduleSerialStart(INTMODULE_USART_PXX_BAUDRATE, true);
   else
     extmodulePxx2Start();
 }
diff --git a/radio/src/targets/taranis/CMakeLists.txt b/radio/src/targets/taranis/CMakeLists.txt
index 1ec29efd5..3471ff424 100644
--- a/radio/src/targets/taranis/CMakeLists.txt
+++ b/radio/src/targets/taranis/CMakeLists.txt
@@ -122,7 +122,7 @@ elseif(PCB STREQUAL XLITE)
   set(GVAR_SCREEN model_gvars.cpp)
   set(STATUS_LEDS YES)
 elseif(PCB STREQUAL XLITES)
-  set(PXX_FREQUENCY "HIGH" CACHE STRING "PXX frequency (LOW / HIGH)")
+  set(PXX_FREQUENCY "HIGH")
   set(PWR_BUTTON "PRESS" CACHE STRING "Pwr button type (PRESS/SWITCH)")
   set(CPU_TYPE STM32F2)
   set(CPU_TYPE_FULL STM32F205xE)  # for size report
diff --git a/radio/src/targets/taranis/board.h b/radio/src/targets/taranis/board.h
index ae5c7bc5a..5150e1f89 100644
--- a/radio/src/targets/taranis/board.h
+++ b/radio/src/targets/taranis/board.h
@@ -21,6 +21,7 @@
 #ifndef _BOARD_H_
 #define _BOARD_H_
 
+#include <inttypes.h>
 #include "../definitions.h"
 #include "cpu_id.h"
 
@@ -180,7 +181,7 @@ void init_serial(uint8_t module, uint32_t baudrate, uint32_t period);
 void disable_serial(uint8_t module);
 void intmoduleStop();
 void intmodulePxxStart();
-void intmoduleSerialStart(uint32_t baudrate);
+void intmoduleSerialStart(uint32_t baudrate, uint8_t rxEnable);
 #if defined(TARANIS_INTERNAL_PPM)
 void intmodulePpmStart(void);
 #endif
diff --git a/radio/src/targets/taranis/extmodule_driver.cpp b/radio/src/targets/taranis/extmodule_driver.cpp
index 72da992ca..31fb234de 100644
--- a/radio/src/targets/taranis/extmodule_driver.cpp
+++ b/radio/src/targets/taranis/extmodule_driver.cpp
@@ -195,16 +195,18 @@ extern "C" void EXTMODULE_USART_IRQHandler(void)
   }
 }
 
-void extmodulePxxStart()
-{
-  extmoduleInvertedSerialStart(EXTMODULE_USART_PXX_BAUDRATE);
-}
-
 void extmodulePxx2Start()
 {
   extmoduleInvertedSerialStart(EXTMODULE_USART_PXX_BAUDRATE);
 }
 #else
+void extmodulePxx2Start()
+{
+  // TODO just enable the S.PORT line (or let telemetry init do it)
+}
+#endif
+
+#if defined(PXX1)
 void extmodulePxxStart()
 {
   EXTERNAL_MODULE_ON();
@@ -239,90 +241,72 @@ void extmodulePxxStart()
   NVIC_EnableIRQ(EXTMODULE_TIMER_CC_IRQn);
   NVIC_SetPriority(EXTMODULE_TIMER_CC_IRQn, 7);
 }
-
-void extmodulePxx2Start()
-{
-  // TODO just enable the S.PORT line (or let telemetry init do it)
-}
 #endif
 
 void extmoduleSendNextFrame()
 {
-  if (moduleSettings[EXTERNAL_MODULE].protocol == PROTOCOL_CHANNELS_PPM) {
-    EXTMODULE_TIMER->CCR1 = GET_MODULE_PPM_DELAY(EXTERNAL_MODULE) * 2;
-    EXTMODULE_TIMER->CCER = EXTMODULE_TIMER_OUTPUT_ENABLE | (GET_MODULE_PPM_POLARITY(EXTERNAL_MODULE) ? EXTMODULE_TIMER_OUTPUT_POLARITY : 0); //     // we are using complementary output so logic has to be reversed here
-    EXTMODULE_TIMER->CCR2 = *(extmodulePulsesData.ppm.ptr - 1) - 4000; // 2mS in advance
-    EXTMODULE_TIMER_DMA_STREAM->CR &= ~DMA_SxCR_EN; // Disable DMA
-    EXTMODULE_TIMER_DMA_STREAM->CR |= EXTMODULE_TIMER_DMA_CHANNEL | DMA_SxCR_DIR_0 | DMA_SxCR_MINC | DMA_SxCR_PSIZE_0 | DMA_SxCR_MSIZE_0 | DMA_SxCR_PL_0 | DMA_SxCR_PL_1;
-    EXTMODULE_TIMER_DMA_STREAM->PAR = CONVERT_PTR_UINT(&EXTMODULE_TIMER->ARR);
-    EXTMODULE_TIMER_DMA_STREAM->M0AR = CONVERT_PTR_UINT(extmodulePulsesData.ppm.pulses);
-    EXTMODULE_TIMER_DMA_STREAM->NDTR = extmodulePulsesData.ppm.ptr - extmodulePulsesData.ppm.pulses;
-    EXTMODULE_TIMER_DMA_STREAM->CR |= DMA_SxCR_EN | DMA_SxCR_TCIE; // Enable DMA
-  }
+  switch(moduleSettings[EXTERNAL_MODULE].protocol) {
+    case PROTOCOL_CHANNELS_PPM:
+      EXTMODULE_TIMER->CCR1 = GET_MODULE_PPM_DELAY(EXTERNAL_MODULE) * 2;
+      EXTMODULE_TIMER->CCER = EXTMODULE_TIMER_OUTPUT_ENABLE | (GET_MODULE_PPM_POLARITY(EXTERNAL_MODULE) ? EXTMODULE_TIMER_OUTPUT_POLARITY : 0); //     // we are using complementary output so logic has to be reversed here
+      EXTMODULE_TIMER->CCR2 = *(extmodulePulsesData.ppm.ptr - 1) - 4000; // 2mS in advance
+      EXTMODULE_TIMER_DMA_STREAM->CR &= ~DMA_SxCR_EN; // Disable DMA
+      EXTMODULE_TIMER_DMA_STREAM->CR |= EXTMODULE_TIMER_DMA_CHANNEL | DMA_SxCR_DIR_0 | DMA_SxCR_MINC | DMA_SxCR_PSIZE_0 | DMA_SxCR_MSIZE_0 | DMA_SxCR_PL_0 | DMA_SxCR_PL_1;
+      EXTMODULE_TIMER_DMA_STREAM->PAR = CONVERT_PTR_UINT(&EXTMODULE_TIMER->ARR);
+      EXTMODULE_TIMER_DMA_STREAM->M0AR = CONVERT_PTR_UINT(extmodulePulsesData.ppm.pulses);
+      EXTMODULE_TIMER_DMA_STREAM->NDTR = extmodulePulsesData.ppm.ptr - extmodulePulsesData.ppm.pulses;
+      EXTMODULE_TIMER_DMA_STREAM->CR |= DMA_SxCR_EN | DMA_SxCR_TCIE; // Enable DMA
+      break;
+
 #if defined(PXX1)
-  else if (moduleSettings[EXTERNAL_MODULE].protocol == PROTOCOL_CHANNELS_PXX1) {
-#if defined(EXTMODULE_USART)
-    DMA_InitTypeDef DMA_InitStructure;
-    DMA_DeInit(EXTMODULE_USART_DMA_STREAM);
-    DMA_InitStructure.DMA_Channel = EXTMODULE_USART_DMA_CHANNEL;
-    DMA_InitStructure.DMA_PeripheralBaseAddr = CONVERT_PTR_UINT(&EXTMODULE_USART->DR);
-    DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral;
-    DMA_InitStructure.DMA_Memory0BaseAddr = CONVERT_PTR_UINT(extmodulePulsesData.pxx_uart.getData());
-    DMA_InitStructure.DMA_BufferSize = extmodulePulsesData.pxx_uart.getSize();
-    DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
-    DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
-    DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
-    DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
-    DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
-    DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh;
-    DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;
-    DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;
-    DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
-    DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
-    DMA_Init(EXTMODULE_USART_DMA_STREAM, &DMA_InitStructure);
-    DMA_Cmd(EXTMODULE_USART_DMA_STREAM, ENABLE);
-    USART_DMACmd(EXTMODULE_USART, USART_DMAReq_Tx, ENABLE);
-    EXTMODULE_TIMER->DIER |= TIM_DIER_CC2IE;
-#else
-    EXTMODULE_TIMER->CCR2 = extmodulePulsesData.pxx.getLast() - 4000; // 2mS in advance
-    EXTMODULE_TIMER_DMA_STREAM->CR &= ~DMA_SxCR_EN; // Disable DMA
-    EXTMODULE_TIMER_DMA_STREAM->CR |= EXTMODULE_TIMER_DMA_CHANNEL | DMA_SxCR_DIR_0 | DMA_SxCR_MINC | DMA_SxCR_PSIZE_0 | DMA_SxCR_MSIZE_0 | DMA_SxCR_PL_0 | DMA_SxCR_PL_1;
-    EXTMODULE_TIMER_DMA_STREAM->PAR = CONVERT_PTR_UINT(&EXTMODULE_TIMER->ARR);
-    EXTMODULE_TIMER_DMA_STREAM->M0AR = CONVERT_PTR_UINT(extmodulePulsesData.pxx.getData());
-    EXTMODULE_TIMER_DMA_STREAM->NDTR = extmodulePulsesData.pxx.getSize();
-    EXTMODULE_TIMER_DMA_STREAM->CR |= DMA_SxCR_EN | DMA_SxCR_TCIE; // Enable DMA
-#endif
-  }
+    case PROTOCOL_CHANNELS_PXX1:
+      EXTMODULE_TIMER->CCR2 = extmodulePulsesData.pxx.getLast() - 4000; // 2mS in advance
+      EXTMODULE_TIMER_DMA_STREAM->CR &= ~DMA_SxCR_EN; // Disable DMA
+      EXTMODULE_TIMER_DMA_STREAM->CR |= EXTMODULE_TIMER_DMA_CHANNEL | DMA_SxCR_DIR_0 | DMA_SxCR_MINC | DMA_SxCR_PSIZE_0 | DMA_SxCR_MSIZE_0 | DMA_SxCR_PL_0 | DMA_SxCR_PL_1;
+      EXTMODULE_TIMER_DMA_STREAM->PAR = CONVERT_PTR_UINT(&EXTMODULE_TIMER->ARR);
+      EXTMODULE_TIMER_DMA_STREAM->M0AR = CONVERT_PTR_UINT(extmodulePulsesData.pxx.getData());
+      EXTMODULE_TIMER_DMA_STREAM->NDTR = extmodulePulsesData.pxx.getSize();
+      EXTMODULE_TIMER_DMA_STREAM->CR |= DMA_SxCR_EN | DMA_SxCR_TCIE; // Enable DMA
+      break;
 #endif
+
 #if defined(PXX2)
-  else if (moduleSettings[EXTERNAL_MODULE].protocol == PROTOCOL_CHANNELS_PXX2) {
-    #if defined(EXTMODULE_USART)
-      extmoduleSendBuffer(extmodulePulsesData.pxx2.getData(), extmodulePulsesData.pxx2.getSize());
-    #else
-      sportSendBuffer(extmodulePulsesData.pxx2.getData(), extmodulePulsesData.pxx2.getSize());
-    #endif
-  }
+    case PROTOCOL_CHANNELS_PXX2:
+      #if defined(EXTMODULE_USART)
+        extmoduleSendBuffer(extmodulePulsesData.pxx2.getData(), extmodulePulsesData.pxx2.getSize());
+      #else
+        sportSendBuffer(extmodulePulsesData.pxx2.getData(), extmodulePulsesData.pxx2.getSize());
+      #endif
+      break;
 #endif
+
 #if defined(DSM2)
-  else if (IS_DSM2_PROTOCOL(moduleSettings[EXTERNAL_MODULE].protocol) || IS_MULTIMODULE_PROTOCOL(moduleSettings[EXTERNAL_MODULE].protocol) || IS_SBUS_PROTOCOL(moduleSettings[EXTERNAL_MODULE].protocol)) {
-    if (IS_SBUS_PROTOCOL(moduleSettings[EXTERNAL_MODULE].protocol))
+    case PROTOCOL_CHANNELS_SBUS:
       EXTMODULE_TIMER->CCER = EXTMODULE_TIMER_OUTPUT_ENABLE | (GET_SBUS_POLARITY(EXTERNAL_MODULE) ? EXTMODULE_TIMER_OUTPUT_POLARITY : 0); // reverse polarity for Sbus if needed
-    EXTMODULE_TIMER->CCR2 = *(extmodulePulsesData.dsm2.ptr - 1) - 4000; // 2mS in advance
-    EXTMODULE_TIMER_DMA_STREAM->CR &= ~DMA_SxCR_EN; // Disable DMA
-    EXTMODULE_TIMER_DMA_STREAM->CR |= EXTMODULE_TIMER_DMA_CHANNEL | DMA_SxCR_DIR_0 | DMA_SxCR_MINC | DMA_SxCR_PSIZE_0 | DMA_SxCR_MSIZE_0 | DMA_SxCR_PL_0 | DMA_SxCR_PL_1;
-    EXTMODULE_TIMER_DMA_STREAM->PAR = CONVERT_PTR_UINT(&EXTMODULE_TIMER->ARR);
-    EXTMODULE_TIMER_DMA_STREAM->M0AR = CONVERT_PTR_UINT(extmodulePulsesData.dsm2.pulses);
-    EXTMODULE_TIMER_DMA_STREAM->NDTR = extmodulePulsesData.dsm2.ptr - extmodulePulsesData.dsm2.pulses;
-    EXTMODULE_TIMER_DMA_STREAM->CR |= DMA_SxCR_EN | DMA_SxCR_TCIE; // Enable DMA
-  }
+      // no break
+    case PROTOCOL_CHANNELS_DSM2_LP45:
+    case PROTOCOL_CHANNELS_DSM2_DSM2:
+    case PROTOCOL_CHANNELS_DSM2_DSMX:
+    case PROTOCOL_CHANNELS_MULTIMODULE:
+      EXTMODULE_TIMER->CCR2 = *(extmodulePulsesData.dsm2.ptr - 1) - 4000; // 2mS in advance
+      EXTMODULE_TIMER_DMA_STREAM->CR &= ~DMA_SxCR_EN; // Disable DMA
+      EXTMODULE_TIMER_DMA_STREAM->CR |= EXTMODULE_TIMER_DMA_CHANNEL | DMA_SxCR_DIR_0 | DMA_SxCR_MINC | DMA_SxCR_PSIZE_0 | DMA_SxCR_MSIZE_0 | DMA_SxCR_PL_0 | DMA_SxCR_PL_1;
+      EXTMODULE_TIMER_DMA_STREAM->PAR = CONVERT_PTR_UINT(&EXTMODULE_TIMER->ARR);
+      EXTMODULE_TIMER_DMA_STREAM->M0AR = CONVERT_PTR_UINT(extmodulePulsesData.dsm2.pulses);
+      EXTMODULE_TIMER_DMA_STREAM->NDTR = extmodulePulsesData.dsm2.ptr - extmodulePulsesData.dsm2.pulses;
+      EXTMODULE_TIMER_DMA_STREAM->CR |= DMA_SxCR_EN | DMA_SxCR_TCIE; // Enable DMA
+      break;
 #endif
+
 #if defined(CROSSFIRE)
-  else if (moduleSettings[EXTERNAL_MODULE].protocol == PROTOCOL_CHANNELS_CROSSFIRE) {
-    sportSendBuffer(extmodulePulsesData.crossfire.pulses, extmodulePulsesData.crossfire.length);
-  }
+    case PROTOCOL_CHANNELS_CROSSFIRE:
+      sportSendBuffer(extmodulePulsesData.crossfire.pulses, extmodulePulsesData.crossfire.length);
+      break;
 #endif
-  else {
-    EXTMODULE_TIMER->DIER |= TIM_DIER_CC2IE;
+
+    default:
+      EXTMODULE_TIMER->DIER |= TIM_DIER_CC2IE;
+      break;
   }
 }
 
diff --git a/radio/src/targets/taranis/intmodule_pulses_driver.cpp b/radio/src/targets/taranis/intmodule_pulses_driver.cpp
index 5150fe296..49144f288 100644
--- a/radio/src/targets/taranis/intmodule_pulses_driver.cpp
+++ b/radio/src/targets/taranis/intmodule_pulses_driver.cpp
@@ -65,7 +65,7 @@ void intmoduleSendNextFrame()
   }
 }
 
-void intmoduleSerialStart(uint32_t baudrate)
+void intmoduleSerialStart(uint32_t baudrate, uint8_t rxEnable)
 {
   // nothing, the pulses will be sent through telemetry port
 }
diff --git a/radio/src/targets/taranis/pulses_driver.cpp b/radio/src/targets/taranis/pulses_driver.cpp
index 1dd39fc43..11f483c07 100644
--- a/radio/src/targets/taranis/pulses_driver.cpp
+++ b/radio/src/targets/taranis/pulses_driver.cpp
@@ -39,7 +39,7 @@ void disable_pxx(uint8_t module)
 void init_pxx2(uint8_t module)
 {
   if (module == INTERNAL_MODULE)
-    intmoduleSerialStart(INTMODULE_USART_PXX_BAUDRATE);
+    intmoduleSerialStart(INTMODULE_USART_PXX_BAUDRATE, true);
   else
     extmodulePxx2Start();
 }
diff --git a/radio/src/tasks.cpp b/radio/src/tasks.cpp
index 4488cb1ac..a058196b7 100644
--- a/radio/src/tasks.cpp
+++ b/radio/src/tasks.cpp
@@ -73,16 +73,22 @@ bool isForcePowerOffRequested()
   return false;
 }
 
-bool isProtocolSynchronous(uint8_t protocol)
+bool isModuleSynchronous(uint8_t module)
 {
-  return (protocol == PROTOCOL_CHANNELS_PXX2 || protocol == PROTOCOL_CHANNELS_CROSSFIRE || protocol == PROTOCOL_CHANNELS_NONE);
+  uint8_t protocol = moduleSettings[module].protocol;
+  if (protocol == PROTOCOL_CHANNELS_PXX2 || protocol == PROTOCOL_CHANNELS_CROSSFIRE || protocol == PROTOCOL_CHANNELS_NONE)
+    return true;
+#if defined(INTMODULE_USART)
+  if (protocol == PROTOCOL_CHANNELS_PXX1 && module == INTERNAL_MODULE)
+    return true;
+#endif
+  return false;
 }
 
 void sendSynchronousPulses()
 {
   for (uint8_t module = 0; module < NUM_MODULES; module++) {
-    uint8_t protocol = moduleSettings[module].protocol;
-    if (isProtocolSynchronous(protocol) && setupPulses(module)) {
+    if (isModuleSynchronous(module) && setupPulses(module)) {
       if (module == INTERNAL_MODULE)
         intmoduleSendNextFrame();
       else
@@ -184,7 +190,7 @@ void scheduleNextMixerCalculation(uint8_t module, uint16_t period_ms)
 {
   // Schedule next mixer calculation time,
 
-  if (isProtocolSynchronous(moduleSettings[module].protocol)) {
+  if (isModuleSynchronous(module)) {
     nextMixerTime[module] += period_ms / RTOS_MS_PER_TICK;
     if (nextMixerTime[module] < RTOS_GET_TIME()) {
       // we are late ... let's add some small delay