diff --git a/radio/src/targets/common/arm/stm32/extmodule_driver.cpp b/radio/src/targets/common/arm/stm32/extmodule_driver.cpp
index daf9e5238..3119b7f3c 100644
--- a/radio/src/targets/common/arm/stm32/extmodule_driver.cpp
+++ b/radio/src/targets/common/arm/stm32/extmodule_driver.cpp
@@ -73,20 +73,8 @@ static void config_ppm_output(uint16_t ppm_delay, bool polarity)
   // AAR register defines duration of each pulse, it is
   // updated after every pulse in Update interrupt handler.
 
-  LL_TIM_OC_InitTypeDef ocInit;
-  LL_TIM_OC_StructInit(&ocInit);
-
-  ocInit.OCMode = LL_TIM_OCMODE_PWM1;
-  ocInit.OCState = LL_TIM_OCSTATE_ENABLE;
-
-  if (polarity) {
-    ocInit.OCPolarity = LL_TIM_OCPOLARITY_LOW;
-  } else {
-    ocInit.OCPolarity = LL_TIM_OCPOLARITY_HIGH;
-  }
-
-  ocInit.CompareValue = ppm_delay * 2;
-  stm32_pulse_config_output(&extmoduleTimer, &ocInit);  
+  stm32_pulse_config_output(&extmoduleTimer, !polarity, LL_TIM_OCMODE_PWM1,
+                            ppm_delay * 2);
 }
 
 void extmodulePpmStart(uint16_t ppm_delay, bool polarity)
@@ -114,28 +102,17 @@ void extmoduleSendNextFramePpm(void* pulses, uint16_t length,
 void extmodulePxx1PulsesStart()
 {
   EXTERNAL_MODULE_ON();
-
-  LL_TIM_OC_InitTypeDef ocInit;
-  LL_TIM_OC_StructInit(&ocInit);
-
-  ocInit.OCMode = LL_TIM_OCMODE_PWM1;
-  ocInit.OCState = LL_TIM_OCSTATE_ENABLE;
-  ocInit.OCPolarity = LL_TIM_OCPOLARITY_LOW;
-  ocInit.CompareValue = 9 * 2; // 9 uS
-
-  stm32_pulse_config_output(&extmoduleTimer, &ocInit);
-
+  stm32_pulse_config_output(&extmoduleTimer, false, LL_TIM_OCMODE_PWM1, 9 * 2);
   stm32_pulse_init(&extmoduleTimer);
 }
 
 void extmoduleSendNextFramePxx1(const void* pulses, uint16_t length)
 {
-  if (!stm32_pulse_if_not_running_disable(&extmoduleTimer))
-    return;
+  if (!stm32_pulse_if_not_running_disable(&extmoduleTimer)) return;
 
   // Start DMA request and re-enable timer
-  stm32_pulse_start_dma_req(&extmoduleTimer, pulses, length,
-                            LL_TIM_OCMODE_PWM1, 9 * 2);
+  stm32_pulse_start_dma_req(&extmoduleTimer, pulses, length, LL_TIM_OCMODE_PWM1,
+                            9 * 2);
 }
 #endif
 
@@ -144,16 +121,7 @@ void extmoduleSerialStart()
 {
   EXTERNAL_MODULE_ON();
   stm32_pulse_init(&extmoduleTimer);
-
-  LL_TIM_OC_InitTypeDef ocInit;
-  LL_TIM_OC_StructInit(&ocInit);
-
-  ocInit.OCMode = LL_TIM_OCMODE_TOGGLE;
-  ocInit.OCState = LL_TIM_OCSTATE_ENABLE;
-  ocInit.OCPolarity = LL_TIM_OCPOLARITY_HIGH;
-  ocInit.CompareValue = 0;
-
-  stm32_pulse_config_output(&extmoduleTimer, &ocInit);
+  stm32_pulse_config_output(&extmoduleTimer, true, LL_TIM_OCMODE_TOGGLE, 0);
 }
 
 void extmoduleSendNextFrameSoftSerial(const void* pulses, uint16_t length, bool polarity)
diff --git a/radio/src/targets/common/arm/stm32/stm32_pulse_driver.cpp b/radio/src/targets/common/arm/stm32/stm32_pulse_driver.cpp
index 6dbb5bde0..290f87352 100644
--- a/radio/src/targets/common/arm/stm32/stm32_pulse_driver.cpp
+++ b/radio/src/targets/common/arm/stm32/stm32_pulse_driver.cpp
@@ -67,9 +67,36 @@ void stm32_pulse_deinit(const stm32_pulse_timer_t* tim)
   LL_GPIO_Init(tim->GPIOx, &pinInit);
 }
 
-void stm32_pulse_config_output(const stm32_pulse_timer_t* tim, LL_TIM_OC_InitTypeDef* ocInit)
+void stm32_pulse_config_output(const stm32_pulse_timer_t* tim, bool polarity,
+                               uint32_t ocmode, uint32_t cmp_val)
 {
-  LL_TIM_OC_Init(tim->TIMx, tim->TIM_Channel, ocInit);
+  LL_TIM_OC_InitTypeDef ocInit;
+  LL_TIM_OC_StructInit(&ocInit);
+
+  ocInit.OCMode = ocmode;
+  ocInit.CompareValue = cmp_val;
+
+  if (tim->TIM_Channel != LL_TIM_CHANNEL_CH1N) {
+    ocInit.OCState = LL_TIM_OCSTATE_ENABLE;
+  } else {
+    ocInit.OCNState = LL_TIM_OCSTATE_ENABLE;
+    polarity = !polarity;
+  }
+
+  uint32_t ll_polarity;
+  if (polarity) {
+    ll_polarity = LL_TIM_OCPOLARITY_HIGH;
+  } else {
+    ll_polarity = LL_TIM_OCPOLARITY_LOW;
+  }
+
+  if (tim->TIM_Channel != LL_TIM_CHANNEL_CH1N) {
+    ocInit.OCPolarity = ll_polarity;
+  } else {
+    ocInit.OCNPolarity = ll_polarity;
+  }
+  
+  LL_TIM_OC_Init(tim->TIMx, tim->TIM_Channel, &ocInit);
   LL_TIM_OC_EnablePreload(tim->TIMx, tim->TIM_Channel);
 
   if (IS_TIM_BREAK_INSTANCE(tim->TIMx)) {
diff --git a/radio/src/targets/common/arm/stm32/stm32_pulse_driver.h b/radio/src/targets/common/arm/stm32/stm32_pulse_driver.h
index cce089da8..299ee6fec 100644
--- a/radio/src/targets/common/arm/stm32/stm32_pulse_driver.h
+++ b/radio/src/targets/common/arm/stm32/stm32_pulse_driver.h
@@ -43,7 +43,10 @@ struct stm32_pulse_timer_t {
 
 void stm32_pulse_init(const stm32_pulse_timer_t* tim);
 void stm32_pulse_deinit(const stm32_pulse_timer_t* tim);
-void stm32_pulse_config_output(const stm32_pulse_timer_t* tim, LL_TIM_OC_InitTypeDef* ocInit);
+
+void stm32_pulse_config_output(const stm32_pulse_timer_t* tim, bool polarity,
+                               uint32_t ocmode, uint32_t cmp_val);
+
 void stm32_pulse_set_polarity(const stm32_pulse_timer_t* tim, bool polarity);
 
 // return true if it could be disabled without interrupting a pulse train, false otherwise