STM32H745 ADC and DMA

[jgauthier]

I have read quite a few posts, reference, and KBs trying to get this to work - but I'm stuck.

Challenge: Trying to get STM32H745 working with ADC1 (and eventually ADC3) with DMA.

What I am experiencing: All my results are coming back as "65535" (even when there is not a 3.3V on the input)

What I've done/read:

I've referred to this KB quite a bit:

https://community.st.com/s/article/FAQ-DMA-is-not-working-on-STM32H7-devices

So I have an understanding of some of the challenges. I am using "Solution example 3: Use Cache maintenance functions" as my guide. However, it's unclear to me if I need to make an effort to move the memory locations as in "Solution example 1" and "Solution example 2".

Relevant code:

main.c

/* MPU Configuration--------------------------------------------------------*/
  MPU_Config();
 
  /* Enable I-Cache---------------------------------------------------------*/
  SCB_EnableICache();
 
  /* Enable D-Cache---------------------------------------------------------*/
  SCB_EnableDCache();

And further:

MX_GPIO_Init();
  MX_ADC1_Init();
  MX_ADC3_Init();
  MX_BDMA_Init();
  MX_DMA_Init();
  MX_FDCAN1_Init();
  MX_FDCAN2_Init();
  MX_USART3_UART_Init();

ADC:

hadc1.Instance = ADC1;
  hadc1.Init.ClockPrescaler = ADC_CLOCK_ASYNC_DIV1;
  hadc1.Init.Resolution = ADC_RESOLUTION_16B;
  hadc1.Init.ScanConvMode = ADC_SCAN_ENABLE;
  hadc1.Init.EOCSelection = ADC_EOC_SEQ_CONV;
  hadc1.Init.LowPowerAutoWait = DISABLE;
  hadc1.Init.ContinuousConvMode = ENABLE;
  hadc1.Init.NbrOfConversion = 4;
  hadc1.Init.DiscontinuousConvMode = DISABLE;
  hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;
  hadc1.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
  hadc1.Init.ConversionDataManagement = ADC_CONVERSIONDATA_DMA_CIRCULAR;
  hadc1.Init.Overrun = ADC_OVR_DATA_PRESERVED;
  hadc1.Init.LeftBitShift = ADC_LEFTBITSHIFT_NONE;
 
[ channels are configured ]
  sConfig.Channel = ADC_CHANNEL_7;
  sConfig.Rank = ADC_REGULAR_RANK_1;
  sConfig.SamplingTime = ADC_SAMPLETIME_1CYCLE_5;
  sConfig.SingleDiff = ADC_SINGLE_ENDED;
  sConfig.OffsetNumber = ADC_OFFSET_NONE;
  sConfig.Offset = 0;
  sConfig.OffsetSignedSaturation = DISABLE;
 
[DMA is configured]
 
    hdma_adc1.Instance = DMA1_Stream0;
    hdma_adc1.Init.Request = DMA_REQUEST_ADC1;
    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_CIRCULAR;
    hdma_adc1.Init.Priority = DMA_PRIORITY_LOW;
    hdma_adc1.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
    if (HAL_DMA_Init(&hdma_adc1) != HAL_OK)
    {
      Error_Handler();
    }
 
    __HAL_LINKDMA(adcHandle,DMA_Handle,hdma_adc1);
 
    /* ADC1 interrupt Init */
    HAL_NVIC_SetPriority(ADC_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(ADC_IRQn);

User code:

#define ADC1_CONVERTED_DATA_BUFFER_SIZE   ((uint32_t)  32)   /* Size of array aADCxConvertedData[] */
#define ADC3_CONVERTED_DATA_BUFFER_SIZE   ((uint32_t)  32)   /* Size of array aADCxConvertedData[] */
 
ALIGN_32BYTES (static uint16_t   aADC1ConvertedData[ADC1_CONVERTED_DATA_BUFFER_SIZE]);
ALIGN_32BYTES (static uint16_t   aADC3ConvertedData[ADC3_CONVERTED_DATA_BUFFER_SIZE]);
 
void calibrate_adc() {
 
  if (HAL_ADCEx_LinearCalibration_FactorLoad(&hadc1) != HAL_OK) {
    serprintf("Could not load linear calibration for adc1.");
  }
 
  if (HAL_ADCEx_LinearCalibration_FactorLoad(&hadc3) != HAL_OK) {
    serprintf("Could not load linear calibration for adc3.");
  }
 
  /* Run the ADC calibration in single-ended mode */
  if (HAL_ADCEx_Calibration_Start(&hadc1, ADC_CALIB_OFFSET, ADC_SINGLE_ENDED) != HAL_OK) {
    /* Calibration Error */
    serprintf("ADC1 calibration error.");
    Error_Handler();
  }
  HAL_Delay(50);
  /* Run the ADC calibration in single-ended mode */
  if (HAL_ADCEx_Calibration_Start(&hadc3, ADC_CALIB_OFFSET, ADC_SINGLE_ENDED) != HAL_OK) {
    /* Calibration Error */
    serprintf("ADC3 calibration error.");
    Error_Handler();
  }
  HAL_Delay(50);
 
  HAL_ADC_Start_DMA(&hadc1, (uint32_t*) aADC1ConvertedData, ADC1_CONVERTED_DATA_BUFFER_SIZE);
  //HAL_ADC_Start_DMA(&hadc3, (uint32_t*) aADC3ConvertedData, ADC3_CONVERTED_DATA_BUFFER_SIZE);
 
}
 
void HAL_ADC_ConvHalfCpltCallback(ADC_HandleTypeDef* hadc)
{
  /* Invalidate Data Cache to get the updated content of the SRAM on the first half of the ADC converted data buffer: 32 bytes */
  SCB_InvalidateDCache_by_Addr((uint32_t*)((uint32_t)aADC1ConvertedData), ADC1_CONVERTED_DATA_BUFFER_SIZE);
  SCB_InvalidateDCache_by_Addr((uint32_t*)((uint32_t)aADC3ConvertedData), ADC3_CONVERTED_DATA_BUFFER_SIZE);
 
}
 void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc)
{
   /* Invalidate Data Cache to get the updated content of the SRAM on the second half of the ADC converted data buffer: 32 bytes */
  SCB_InvalidateDCache_by_Addr((uint32_t*)((uint32_t)aADC1ConvertedData), ADC1_CONVERTED_DATA_BUFFER_SIZE);
  SCB_InvalidateDCache_by_Addr((uint32_t*)((uint32_t)aADC3ConvertedData), ADC3_CONVERTED_DATA_BUFFER_SIZE);   
 
}

Linker script:

MEMORY
{
  RAM_D1 (xrw)   : ORIGIN = 0x24000000, LENGTH =  512K
  FLASH  (rx)    : ORIGIN = 0x08000000, LENGTH = 1024K    /* Memory is divided. Actual start is 0x08000000 and actual length is 2048K */
  DTCMRAM (xrw)  : ORIGIN = 0x20000000, LENGTH = 128K
  RAM_D2 (xrw)   : ORIGIN = 0x30000000, LENGTH = 288K
  RAM_D3 (xrw)   : ORIGIN = 0x38000000, LENGTH = 64K
  ITCMRAM (xrw)  : ORIGIN = 0x00000000, LENGTH = 64K
}

[Foued_KH]

Hello @Community member​ ,

When DMA is used, the MX_DMA_Init shall always be called before any other HAL_***_Init (where *** is any peripheral with a HW dependency on DMA init code).

So try to initiate DMA before the ADC :

MX_GPIO_Init();
 
MX_DMA_Init();
MX_BDMA_Init();
 
MX_ADC1_Init();
MX_ADC3_Init();
MX_FDCAN1_Init();
MX_FDCAN2_Init();
MX_USART3_UART_Init();

Foued

[jgauthier]

The code was generated by CubeMX, and I have read about the problem where they are initialized in the wrong order. I have manually swapped them but the problem still exists.

[jgauthier · Accepted solution]

Wanted to come back and indicate I solved this. This is a custom board and the designer used an analog reference IC (MCP1501) and I discovered that the shutdown pin was wired incorrectly, thus shutting it down.