HAL_DAC_Start_DMA stops on start calling HAL_DAC_ErrorCallbackCh1

[RPere.4]

if (HAL_DAC_Start(&hdac4, DAC_CHANNEL_1))
  {
  /* DAC conversion start error */
  Error_Handler();
  }
 
 if (HAL_OPAMP_Start(&hopamp4) != HAL_OK)
  {
  /* OPAMP  start error */
   Error_Handler();
  }
 
  HAL_TIM_Base_Start(&htim7);
//   while(1)
//  	 HAL_DAC_SetValue(&hdac4, DAC_CHANNEL_1, DAC_ALIGN_12B_R, Dacbuffers[0][0]);
  if (HAL_DAC_Start_DMA(&hdac4, DAC_CHANNEL_1,(uint32_t *) Dacbuffers[0], DAC_BUFFER_SIZE, DAC_ALIGN_12B_R) != HAL_OK)
  {
  /* DAC conversion start error */
  Error_Handler();
  }

Project is Cubemx generated. Everything works fine without DMA and i get result on DAC output. Trying to start DMA immediately stops with calling HAL_DAC_ErrorCallbackCh1. What can be the reason for this?

Cubemx generated code

DAC_HandleTypeDef hdac4;
DMA_HandleTypeDef hdma_dac4_ch1;
 
/* DAC4 init function */
void MX_DAC4_Init(void)
{
  DAC_ChannelConfTypeDef sConfig = {0};
 
  /** DAC Initialization 
  */
  hdac4.Instance = DAC4;
  if (HAL_DAC_Init(&hdac4) != HAL_OK)
  {
    Error_Handler();
  }
  /** DAC channel OUT1 config 
  */
  sConfig.DAC_HighFrequency = DAC_HIGH_FREQUENCY_INTERFACE_MODE_AUTOMATIC;
  sConfig.DAC_DMADoubleDataMode = DISABLE;
  sConfig.DAC_SignedFormat = DISABLE;
  sConfig.DAC_SampleAndHold = DAC_SAMPLEANDHOLD_DISABLE;
  sConfig.DAC_Trigger = DAC_TRIGGER_T7_TRGO;
  sConfig.DAC_Trigger2 = DAC_TRIGGER_NONE;
  sConfig.DAC_OutputBuffer = DAC_OUTPUTBUFFER_DISABLE;
  sConfig.DAC_ConnectOnChipPeripheral = DAC_CHIPCONNECT_ENABLE;
  sConfig.DAC_UserTrimming = DAC_TRIMMING_FACTORY;
  if (HAL_DAC_ConfigChannel(&hdac4, &sConfig, DAC_CHANNEL_1) != HAL_OK)
  {
    Error_Handler();
  }
 
}
 
void HAL_DAC_MspInit(DAC_HandleTypeDef* dacHandle)
{
 
  if(dacHandle->Instance==DAC4)
  {
  /* USER CODE BEGIN DAC4_MspInit 0 */
 
  /* USER CODE END DAC4_MspInit 0 */
    /* DAC4 clock enable */
    __HAL_RCC_DAC4_CLK_ENABLE();
  
    /* DAC4 DMA Init */
    /* DAC4_CH1 Init */
    hdma_dac4_ch1.Instance = DMA2_Channel1;
    hdma_dac4_ch1.Init.Request = DMA_REQUEST_DAC4_CHANNEL1;
    hdma_dac4_ch1.Init.Direction = DMA_MEMORY_TO_PERIPH;
    hdma_dac4_ch1.Init.PeriphInc = DMA_PINC_DISABLE;
    hdma_dac4_ch1.Init.MemInc = DMA_MINC_ENABLE;
    hdma_dac4_ch1.Init.PeriphDataAlignment = DMA_PDATAALIGN_HALFWORD;
    hdma_dac4_ch1.Init.MemDataAlignment = DMA_MDATAALIGN_HALFWORD;
    hdma_dac4_ch1.Init.Mode = DMA_CIRCULAR;
    hdma_dac4_ch1.Init.Priority = DMA_PRIORITY_VERY_HIGH;
    if (HAL_DMA_Init(&hdma_dac4_ch1) != HAL_OK)
    {
      Error_Handler();
    }
 
    __HAL_LINKDMA(dacHandle,DMA_Handle1,hdma_dac4_ch1);
 
  /* USER CODE BEGIN DAC4_MspInit 1 */
 
  /* USER CODE END DAC4_MspInit 1 */
  }
}

[Sirac]

Hi,

do you initialise DMA before ?

This is not righ => (uint32_t *) Dacbuffers[0]

Remplace by simply (uint32_t *) Dacbuffers, or at least (uint32_t *) &Dacbuffers[0]

[RPere.4]

Sorry to confuse you

Dacbuffers[2][DAC_BUFFER_SIZE] Supposed to be double buffer

What do you mean by initialization. Typically cubemex do this for you (second snippet)

[Sirac]

OK for Dacbuffers[2][DAC_BUFFER_SIZE]

Yes normally CubeMx generate for you a function call MX_DMA_Init() witch enable Irq and clk, but as I can't see this on your code I ask.

Do you configure the pin as analog.

You can try to you place breakpoint on DAC Irq and follow until HAL_DAC_ErrorCallbackCh1 to see what's going wrong.

[RPere.4]

Sure it is generated

void MX_DMA_Init(void) 
{
 
  /* DMA controller clock enable */
  __HAL_RCC_DMAMUX1_CLK_ENABLE();
  __HAL_RCC_DMA2_CLK_ENABLE();
  __HAL_RCC_DMA1_CLK_ENABLE();
 
  /* DMA interrupt init */
  /* DMA1_Channel1_IRQn interrupt configuration */
  NVIC_SetPriority(DMA1_Channel1_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),5, 0));
  NVIC_EnableIRQ(DMA1_Channel1_IRQn);
  /* DMA1_Channel2_IRQn interrupt configuration */
  NVIC_SetPriority(DMA1_Channel2_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),5, 0));
  NVIC_EnableIRQ(DMA1_Channel2_IRQn);
  /* DMA1_Channel3_IRQn interrupt configuration */
  NVIC_SetPriority(DMA1_Channel3_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),5, 0));
  NVIC_EnableIRQ(DMA1_Channel3_IRQn);
  /* DMA1_Channel4_IRQn interrupt configuration */
  NVIC_SetPriority(DMA1_Channel4_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(),5, 0));
  NVIC_EnableIRQ(DMA1_Channel4_IRQn);
  /* DMA2_Channel1_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(DMA2_Channel1_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(DMA2_Channel1_IRQn);
 
}

Pin is configured correctly. It is high speed DAC and output is through built-in op-amp as follower. See CUBEMX file attached.

And everything is working including DAC output without dma.

[B.Lunce]

I'm curious if you found and answer. I have pretty much the same problem. I notice the DMAUDRx bit gets set immediately after I turn on the timer associated with the DAC channel. Which means the data is triggered too fast. For my application it is way under 1Msps.

[RPere.4 · Accepted solution]

Yes I've found the answer. You need to select destination size as 32 bit despite your source is 16 bit. DMA will do unpacking for you so

hdma_dac4_ch1.Init.PeriphDataAlignment = DMA_PDATAALIGN_HALFWORD; // must be replaced with DMA_PDATAALIGN_WORD

hdma_dac4_ch1.Init.MemDataAlignment = DMA_MDATAALIGN_HALFWORD;

Not sure if your case is the same though....

[B.Lunce]

Yes that was the issue. Thanks! ​