DMA with SAI

[DYann.1]

Hello,

I would like to use DMA with SAI but I am having difficulty writing the code. Can you check if my code is correct and why I cannot retrieve the RX values ?

  /* USER CODE BEGIN 2 */

  HAL_SAI_RegisterCallback(&hsai_BlockA1, HAL_SAI_RX_HALFCOMPLETE_CB_ID, HAL_SAI_RxHalfCpltCallback);
  HAL_SAI_RegisterCallback(&hsai_BlockA1, HAL_SAI_RX_COMPLETE_CB_ID, HAL_SAI_RxCpltCallback);
  fresult= HAL_SAI_Init(&hsai_BlockA1);
  if (fresult != HAL_OK)
  	{
  	return HAL_ERROR;
  	}
  fresult = HAL_SAI_Receive_DMA(&hsai_BlockA1, (uint8_t *)playbuf_RX, (sizeof(playbuf_RX))/4);

  HAL_SAI_RegisterCallback(&hsai_BlockB1, HAL_SAI_TX_HALFCOMPLETE_CB_ID, HAL_SAI_TxHalfCpltCallback);
  HAL_SAI_RegisterCallback(&hsai_BlockB1, HAL_SAI_TX_COMPLETE_CB_ID, HAL_SAI_TxCpltCallback);
  fresult= HAL_SAI_Init(&hsai_BlockB1);
  if (fresult != HAL_OK)
	{
  	return HAL_ERROR;
	}

  fresult = HAL_SAI_Transmit_DMA(&hsai_BlockB1, (uint8_t *)playbuf , (sizeof(playbuf))/4);

With CubeMX I have configured 2 DMAs.

One to send the data and the other to read the data again.
I think I'm missing something for the callback but I don't know how to use it to retrieve the values.

Thank you for your helps. 

Regards.

[DYann.1]

---

@LCE wrote:

Congratulations!

But how did you configure the SAI in RX?

---

I configure SAI_RX via CubeMX and nothing else and the code is :

  HAL_SAI_RegisterCallback(&hsai_BlockA1, HAL_SAI_RX_HALFCOMPLETE_CB_ID, HAL_SAI_RxHalfCpltCallback);
  HAL_SAI_RegisterCallback(&hsai_BlockA1, HAL_SAI_RX_COMPLETE_CB_ID, HAL_SAI_RxCpltCallback);
  fresult= HAL_SAI_Init(&hsai_BlockA1);
  if (fresult != HAL_OK)
  	{
  	return HAL_ERROR;
  	}

The SAI inits is too big to show here but the code is generated from CubeMX.

---

@LCE wrote:

and the part where you start TX / RX.

---

Before I delete my RX array (for example all at 0) and I use this code to retrieve the values :

for (i=0;i<8192;i++)
  {playbuf_RX[i]=0;}

  for (i=0;i<8192;i++)
  {playbuf[i]=i;}
  HAL_SAI_RegisterCallback(&hsai_BlockA1, HAL_SAI_RX_HALFCOMPLETE_CB_ID, HAL_SAI_RxHalfCpltCallback);
  HAL_SAI_RegisterCallback(&hsai_BlockA1, HAL_SAI_RX_COMPLETE_CB_ID, HAL_SAI_RxCpltCallback);
  fresult= HAL_SAI_Init(&hsai_BlockA1);
  if (fresult != HAL_OK)
  	{
  	return HAL_ERROR;
  	}

  HAL_SAI_RegisterCallback(&hsai_BlockB1, HAL_SAI_TX_HALFCOMPLETE_CB_ID, HAL_SAI_TxHalfCpltCallback);
  HAL_SAI_RegisterCallback(&hsai_BlockB1, HAL_SAI_TX_COMPLETE_CB_ID, HAL_SAI_TxCpltCallback);
  fresult= HAL_SAI_Init(&hsai_BlockB1);
  if (fresult != HAL_OK)
	{
  	return HAL_ERROR;
	}
  fresult = HAL_SAI_Receive_DMA(&hsai_BlockA1, (uint8_t *)playbuf_RX, (sizeof(playbuf_RX))/4);
  if (fresult != HAL_OK)
  	{
  	return HAL_ERROR;
  	}
  fresult = HAL_SAI_Transmit_DMA(&hsai_BlockB1, (uint8_t *)playbuf , (sizeof(playbuf))/4);
  if (fresult != HAL_OK)
  	{
  	return HAL_ERROR;
  	}

Just after HAL_SAI_Transmit_DMA you'll have your data in the RX array which comes from the TX array.