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STM32L4 ADC w/ DMA overrun error

seth
Associate II

‎2016-07-22 07:40 AM

Posted on July 22, 2016 at 16:40

I'm having a problem where I can't seem to use the DMA to read ADC values without a perpetual overrun error.

I'm trying to configure the part such that a

 - conversion sequence is started by software.  

 - DMA stores the sequence results in ram

 - Everything stops and waits for the next software trigger.

What I see is

 - The first conversion sequence is started by software

 - The first conversion sequence completes successfully

 - Every subsequent attempt to start a sequence results in immediate overruns.

I'm using a STM32L476G-DISCOVERY board.  I've setup the adc conversions on some pins that were used to read input from a joystick.

I used CubeMX (v4.15.1) to generate this init code using the v1.5.1 HAL firmware package:

void MX_ADC1_Init(void)

{

  ADC_MultiModeTypeDef multimode;

  ADC_ChannelConfTypeDef sConfig;

    /**Common config 

    */

  hadc1.Instance = ADC1;

  hadc1.Init.ClockPrescaler = ADC_CLOCK_ASYNC_DIV1;

  hadc1.Init.Resolution = ADC_RESOLUTION_12B;

  hadc1.Init.DataAlign = ADC_DATAALIGN_RIGHT;

  hadc1.Init.ScanConvMode = ADC_SCAN_ENABLE;

  hadc1.Init.EOCSelection = ADC_EOC_SEQ_CONV;

  hadc1.Init.LowPowerAutoWait = DISABLE;

  hadc1.Init.ContinuousConvMode = ENABLE;

  hadc1.Init.NbrOfConversion = 5;

  hadc1.Init.DiscontinuousConvMode = DISABLE;

  hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;

  hadc1.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;

  hadc1.Init.DMAContinuousRequests = DISABLE;

  hadc1.Init.Overrun = ADC_OVR_DATA_PRESERVED;

  hadc1.Init.OversamplingMode = DISABLE;

  if (HAL_ADC_Init(&hadc1) != HAL_OK)

  {

    Error_Handler();

  }

    /**Configure the ADC multi-mode 

    */

  multimode.Mode = ADC_MODE_INDEPENDENT;

  if (HAL_ADCEx_MultiModeConfigChannel(&hadc1, &multimode) != HAL_OK)

  {

    Error_Handler();

  }

    /**Configure Regular Channel 

    */

  sConfig.Channel = ADC_CHANNEL_5;

  sConfig.Rank = 1;

  sConfig.SamplingTime = ADC_SAMPLETIME_2CYCLES_5;

  sConfig.SingleDiff = ADC_SINGLE_ENDED;

  sConfig.OffsetNumber = ADC_OFFSET_NONE;

  sConfig.Offset = 0;

  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)

  {

    Error_Handler();

  }

    /**Configure Regular Channel 

    */

  sConfig.Channel = ADC_CHANNEL_6;

  sConfig.Rank = 2;

  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)

  {

    Error_Handler();

  }

    /**Configure Regular Channel 

    */

  sConfig.Channel = ADC_CHANNEL_7;

  sConfig.Rank = 3;

  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)

  {

    Error_Handler();

  }

    /**Configure Regular Channel 

    */

  sConfig.Channel = ADC_CHANNEL_8;

  sConfig.Rank = 4;

  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)

  {

    Error_Handler();

  }

    /**Configure Regular Channel 

    */

  sConfig.Channel = ADC_CHANNEL_10;

  sConfig.Rank = 5;

  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)

  {

    Error_Handler();

  }

}

void HAL_ADC_MspInit(ADC_HandleTypeDef* adcHandle)

{

  GPIO_InitTypeDef GPIO_InitStruct;

  if(adcHandle->Instance==ADC1)

  {

  /* USER CODE BEGIN ADC1_MspInit 0 */

  /* USER CODE END ADC1_MspInit 0 */

    /* Peripheral clock enable */

    __HAL_RCC_ADC_CLK_ENABLE();

  

    /**ADC1 GPIO Configuration    

    PA0     ------> ADC1_IN5

    PA1     ------> ADC1_IN6

    PA2     ------> ADC1_IN7

    PA3     ------> ADC1_IN8

    PA5     ------> ADC1_IN10 

    */

    GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3 

                          |GPIO_PIN_5;

    GPIO_InitStruct.Mode = GPIO_MODE_ANALOG_ADC_CONTROL;

    GPIO_InitStruct.Pull = GPIO_NOPULL;

    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    /* Peripheral DMA init*/

  

    hdma_adc1.Instance = DMA1_Channel1;

    hdma_adc1.Init.Request = DMA_REQUEST_0;

    hdma_adc1.Init.Direction = DMA_PERIPH_TO_MEMORY;

    hdma_adc1.Init.PeriphInc = DMA_PINC_DISABLE;

    hdma_adc1.Init.MemInc = DMA_MINC_ENABLE;

    hdma_adc1.Init.PeriphDataAlignment = DMA_PDATAALIGN_HALFWORD;

    hdma_adc1.Init.MemDataAlignment = DMA_MDATAALIGN_HALFWORD;

    hdma_adc1.Init.Mode = DMA_NORMAL;

    hdma_adc1.Init.Priority = DMA_PRIORITY_VERY_HIGH;

    if (HAL_DMA_Init(&hdma_adc1) != HAL_OK)

    {

      Error_Handler();

    }

    __HAL_LINKDMA(adcHandle,DMA_Handle,hdma_adc1);

    /* Peripheral interrupt init */

    HAL_NVIC_SetPriority(ADC1_2_IRQn, 5, 0);

    HAL_NVIC_EnableIRQ(ADC1_2_IRQn);

  /* USER CODE BEGIN ADC1_MspInit 1 */

  /* USER CODE END ADC1_MspInit 1 */

  }

}

The calling code to start ADCs.  You can see I've tried a few of the HAL calls to start things off. The MultiModeStart_DMA call was in the generated code so I assume this one is more correct?

HAL_ADC_Start_DMA(m_bAdc, (uint32_t*)m_pRxBuffer, m_nRxSize);

//HAL_ADCEx_MultiModeStart_DMA(m_bAdc, (uint32_t*)m_pRxBuffer, m_nRxSize);

//HAL_ADC_Start_IT(m_bAdc);

ISR callbacks.  

extern ''C'' void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc)

{

static int togCnt2 = 0;

if (togCnt2 % 2)

HAL_GPIO_WritePin(LD_G_GPIO_Port, LD_G_Pin, GPIO_PIN_SET);

else

HAL_GPIO_WritePin(LD_G_GPIO_Port, LD_G_Pin, GPIO_PIN_RESET);

togCnt2++;

AdcTask* pTask = (AdcTask*)hadc->pReceiverObject;

pTask->processFrame(hadc->Instance->DR);

}

extern ''C'' void HAL_ADC_ErrorCallback(ADC_HandleTypeDef* hadc)

{

//TODO: Reset the ADC to get things going again?

__asm(''NOP'');

}

Thanks in advance for any help on the issue.

Seth
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