STM32L4 ADC w/ DMA overrun error

[seth]

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