Need help understanding HAL_DMA_RegisterCallback function

[Christopher Pappas]

Posted on August 13, 2016 at 17:00

HAL_DMA_RegisterCallback(DMA_HandleTypeDef *hdma, HAL_DMA_CallbackIDTypeDef CallbackID, void (* pCallback)(DMA_HandleTypeDef *_hdma))

These are the parameters I am using in my code:

HAL_DMA_RegisterCallback(&hdma_dac1, HAL_DMA_XFER_HALFCPLT_CB_ID, MyDmaDac1Callback)

Getting errors on this line no matter how many times I try to alter the parameters.

Does a practical real-world code example exist to guide me on the proper syntax for this function? Can anyone offer some assistance?

Thanks,

Christopher

#hal-callback-dma-register

[Amel NASRI]

Posted on August 15, 2016 at 16:25

Hipappas.chris,

This callback function is used in all DMA_FLASHToRAM examples available in the Cube package such asSTM32Cube_FW_F4_V1.0\Projects\STM32F4-Discovery\Examples\DMA\DMA_FLASHToRAM. It is called this way there:

/*##-5- Select Callbacks functions called after Transfer complete and Transfer error */
<br> HAL_DMA_RegisterCallback(&DmaHandle, HAL_DMA_XFER_CPLT_CB_ID, TransferComplete);<br> HAL_DMA_RegisterCallback(&DmaHandle, HAL_DMA_XFER_ERROR_CB_ID, TransferError);

-Mayla-

[Christopher Pappas]

Posted on August 16, 2016 at 02:59

Hey Mayla,

Thank you!! I used the example code DMAFlashtoRam from STM32F7 v1.4.0 firmware and that fixed the syntax errors and everything compiles fine now.

Thanks again for taking time to reply!!

Christopher

[Christopher Pappas]

Posted on August 23, 2016 at 20:24

Actually realized that the callbacks are already defined in the HAL peripheral library, so I did not need to define my own callbacks, I just used the names defined in HAL.

[fuentesj]

Posted on October 28, 2016 at 04:33

Yes, there are default callbacks, for example:

void I2S_DMATxCplt(DMA_HandleTypeDef *hdma);

According to UM1725, if you want to write your own callback you have to assign the function pointer to a variable member:

void HAL_UART_TxCpltCallback(UART_HandleTypeDef *phuart)

{

}

hppp->DMA_handle->XferCpltCallback = HAL_UART_TxCpltCallback;

Also, you can assign the callback using something like this:

HAL_DMA_RegisterCallback(&hppp, HAL_DMA_XFER_CPLT_CB_ID, HAL_UART_TxCpltCallback);

I tried both, but no luck.  My callback is never executed.  The ISR is working fine, but then it executes the default callback.  Any ideas?