STM32H747I-DISCO SAI onboard Microphone DMA error

[Patryk_Kucia]

Post edited by ST moderator to be inline with the community rules especially with the code sharing. In next time please use </> button to paste your code. Please read this post: How to insert source code

HI 

I am having an issue with starting measurements using the on-board microphone. Everything has been configured based on the BSP code, but set up from scratch using CubeMX. The problem is that when I start the DMA Receive

if (HAL_SAI_Receive_DMA(&hsai_BlockA4, (uint8_t*)PDM_Buffer, PDM_BUF_SIZE) != HAL_OK)

{

printf("SAI RX start error!\r\n");

}

else

{

printf("SAI RX started OK");

}

//callbacks:

void HAL_SAI_RxHalfCpltCallback(SAI_HandleTypeDef *hsai)

{

printf("HAL_SAI_RxHalfCpltCallback\n");

}



void HAL_SAI_RxCpltCallback(SAI_HandleTypeDef *hsai)

{

printf("HAL_SAI_RxCpltCallback\n");

}



void HAL_SAI_ErrorCallback(SAI_HandleTypeDef *hsai)

{

printf("SAI error: 0x%08lx\n", hsai->ErrorCode);

}

I immediately get an interrupt reporting a DMA error (128 eror code in decimal).

I have already tried changing the clock frequencies, tried running it on a different core, and also tested with different data sizes, but none of this helped.

My config below: 

[Saket_Om]

Hello @Patryk_Kucia 

---

@Patryk_Kucia wrote:

I immediately get an interrupt reporting a DMA error (128 eror code in decimal).

---

Please could you specify which flag that generate this?

[Patryk_Kucia]

HI 
IDK if it's what you meant but i did it like this :

	void HAL_SAI_ErrorCallback(SAI_HandleTypeDef *hsai)
	{
		printf("SAI error: 0x%08lx\n", hsai->ErrorCode);
		  if (hsai->ErrorCode & HAL_SAI_ERROR_OVR)     printf(" -> Overrun error\n");
		  if (hsai->ErrorCode & HAL_SAI_ERROR_UDR)     printf(" -> Underrun error\n");
		  if (hsai->ErrorCode & HAL_SAI_ERROR_DMA)     printf(" -> DMA transfer error\n");
		  if (hsai->ErrorCode & HAL_SAI_ERROR_TIMEOUT) printf(" -> Timeout error\n");
	}

and got:

-> DMA transfer error

so i went deeper:

    if (hsai->ErrorCode & HAL_SAI_ERROR_DMA)
		    {
		        if (hsai->hdmarx != NULL)
		            printf(" -> DMA RX error: 0x%08lx\n", hsai->hdmarx->ErrorCode);
		        if (hsai->hdmatx != NULL)
		            printf(" -> DMA TX error: 0x%08lx\n", hsai->hdmatx->ErrorCode);
		    }

 and interestingly enough I got:

DMA TX error: 0x00000001

#define HAL_DMA_ERROR_TE (0x00000001U) /*!< Transfer error */

but why is there a sending error if I only want to save?

[Saket_Om]

Hello @Patryk_Kucia 

Could you please share your dma config?

[Patryk_Kucia]

and simply 

  if (HAL_SAI_Receive_DMA(&hsai_BlockA4, (uint8_t*)PDM_Buffer, PDM_BUF_SIZE) != HAL_OK)
  {
      printf("SAI RX start error!\r\n");
  }
  else
  {
      printf("SAI RX started OK\n");
  }