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.

[LCE]

Maybe you should forget about audio for some time and work on the basics.

Make an LED blink.
Then turn it on / off if some GPIO input is high or low.
Then use that GPIO with an interrupt, and so on.

Start simple, and understand that first.

[DYann.1]

---

@LCE wrote:

Maybe you should forget about audio for some time and work on the basics.

Make an LED blink.
Then turn it on / off if some GPIO input is high or low.
Then use that GPIO with an interrupt, and so on.

Start simple, and understand that first.

---

I'm a beginner but I've already done all this.

[DYann.1]

Now it's ok

I just to change the configuration and I configure the SAI in DMA only for transmission but not for reception.

[LCE]

Congratulations!

But how did you configure the SAI in RX?

You are mostly showing not so useful pictures, easier to read would be parts of the code with the (initially hidden) </> code insert button.
So it would be interesting to see the SAI inits, and the part where you start TX / RX.

But good that it's working now.

 

[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.