UART DMA transmission issue

[Foued_KH · Accepted solution]

Hello @LOnGr.1​ ,

DMA1_Stream6_IRQHandler() is an interrupt handler for DMA1 stream 6.It adds a process to clear the transmit completion flag if it is present.

If the flag is not cleared, the next transmission will not be performed.

void DMA1_Stream6_IRQHandler(void)
{
  /* USER CODE BEGIN DMA1_Stream6_IRQn 0 */
  if( LL_DMA_IsActiveFlag_TC6(DMA1) == 1){
    LL_DMA_ClearFlag_TC6(DMA1);
  }
  /* USER CODE END DMA1_Stream6_IRQn 0 */
 
  /* USER CODE BEGIN DMA1_Stream6_IRQn 1 */ /* USER CODE
 
  /* USER CODE END DMA1_Stream6_IRQn 1 */ /* USER CODE
}

Foued

[Foued_KH]

Hello @LOnGr.1​ ,

This works perfectly when using the HAL-function HAL_UART_Transmit_DMA().

Foued

[LOnGr.1]

Yes, I already used the HAL function before, here I am trying to do it with LL

[LOnGr.1]

Hi! Thank you for replying. I am not able to find the function to enable the DMA transfer complete interrupt in the UM (I assume that I have to enbale it).

[LOnGr.1]

Here is it

LL_DMA_EnableIT_TC(DMA_TypeDef *DMAx, uint32_t Stream)

[Foued_KH]

you can find this function inside : stm32fxx_it.c