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 a9c4aaea2..48b4150e0 100644
--- a/radio/src/targets/common/arm/stm32/aux_serial_driver.cpp
+++ b/radio/src/targets/common/arm/stm32/aux_serial_driver.cpp
@@ -141,6 +141,24 @@ static void* auxSerialInit(const etx_serial_init* params)
   return aux_serial_init(&auxSerialState, params);
 }
 
+void (*aux1RxCb)(uint8_t*, uint32_t);
+
+static void aux1_on_rx_byte(uint8_t data)
+{
+  if (aux1RxCb) aux1RxCb(&data, 1);
+}
+
+void aux1SetRxCb(void*, void (*cb)(uint8_t*, uint32_t))
+{
+  aux1RxCb = cb;
+  if (aux1RxCb) {
+    auxSerialCb.on_receive = aux1_on_rx_byte;
+    stm32_usart_deinit_rx_dma(&auxUSART);
+  } else {
+    auxSerialCb.on_receive = nullptr;
+  }
+}
+
 const etx_serial_driver_t AuxSerialDriver = {
   .init = auxSerialInit,
   .deinit = aux_serial_deinit,
@@ -149,7 +167,7 @@ const etx_serial_driver_t AuxSerialDriver = {
   .waitForTxCompleted = aux_wait_tx_completed,
   .getByte = aux_get_byte,
   .getBaudrate = nullptr,
-  .setReceiveCb = nullptr,
+  .setReceiveCb = aux1SetRxCb,
   .setBaudrateCb = nullptr,
 };
 
@@ -202,15 +220,33 @@ static uint8_t aux2SerialOnSend(uint8_t* data)
 
 static etx_serial_callbacks_t aux2SerialCb = {
   .on_send = aux2SerialOnSend,
-  .on_receive = nullptr,
+  .on_receive = nullptr, // TODO: clear on DeInit
   .on_error = nullptr,
 };
 
-void* aux2SerialInit(const etx_serial_init* params)
+static void* aux2SerialInit(const etx_serial_init* params)
 {
   return aux_serial_init(&aux2SerialState, params);
 }
 
+void (*aux2RxCb)(uint8_t*, uint32_t);
+
+static void aux2_on_rx_byte(uint8_t data)
+{
+  if (aux2RxCb) aux2RxCb(&data, 1);
+}
+
+void aux2SetRxCb(void*, void (*cb)(uint8_t*, uint32_t))
+{
+  aux2RxCb = cb;
+  if (aux2RxCb) {
+    aux2SerialCb.on_receive = aux2_on_rx_byte;
+    stm32_usart_deinit_rx_dma(&aux2USART);
+  } else {
+    aux2SerialCb.on_receive = nullptr;
+  }
+}
+
 extern "C" void AUX2_SERIAL_USART_IRQHandler(void)
 {
   DEBUG_INTERRUPT(INT_SER2);
@@ -225,7 +261,7 @@ const etx_serial_driver_t Aux2SerialDriver = {
   .waitForTxCompleted = aux_wait_tx_completed,
   .getByte = aux_get_byte,
   .getBaudrate = nullptr,
-  .setReceiveCb = nullptr,
+  .setReceiveCb = aux2SetRxCb,
   .setBaudrateCb = nullptr,
 };
 
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 5ac82b0b8..e31819c54 100644
--- a/radio/src/targets/common/arm/stm32/stm32_usart_driver.cpp
+++ b/radio/src/targets/common/arm/stm32/stm32_usart_driver.cpp
@@ -24,6 +24,8 @@
 
 void stm32_usart_init_rx_dma(const stm32_usart_t* usart, void* buffer, uint32_t length)
 {
+  if (!usart->rxDMA) return;
+
   // Disable IRQ based RX
   LL_USART_DisableIT_RXNE(usart->USARTx);
 
@@ -49,6 +51,18 @@ void stm32_usart_init_rx_dma(const stm32_usart_t* usart, void* buffer, uint32_t
   LL_DMA_EnableStream(usart->rxDMA, usart->rxDMA_Stream);
 }
 
+void stm32_usart_deinit_rx_dma(const stm32_usart_t* usart)
+{
+  if (!usart->rxDMA) return;
+
+  LL_DMA_DeInit(usart->rxDMA, usart->rxDMA_Stream);
+
+  // Enable IRQ based RX
+  LL_USART_EnableIT_RXNE(usart->USARTx);
+  NVIC_SetPriority(usart->IRQn, usart->IRQ_Prio);
+  NVIC_EnableIRQ(usart->IRQn);
+}
+
 void stm32_usart_init(const stm32_usart_t* usart, const etx_serial_init* params)
 {
   LL_USART_DeInit(usart->USARTx);
@@ -118,6 +132,9 @@ void stm32_usart_init(const stm32_usart_t* usart, const etx_serial_init* params)
 
 void stm32_usart_deinit(const stm32_usart_t* usart)
 {
+  if (usart->rxDMA) {
+    LL_DMA_DeInit(usart->rxDMA, usart->rxDMA_Stream);
+  }
   if (usart->txDMA) {
     LL_DMA_DeInit(usart->txDMA, usart->txDMA_Stream);
   }
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 1671d49b4..17f0cc6e0 100644
--- a/radio/src/targets/common/arm/stm32/stm32_usart_driver.h
+++ b/radio/src/targets/common/arm/stm32/stm32_usart_driver.h
@@ -50,6 +50,7 @@ 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_deinit_rx_dma(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);