DMA data from ADC does not refresh

jmiguelg · ‎2015-07-21

Posted on July 21, 2015 at 14:44

Hello all,

I am writing an application on a STM32F4 which reads from two sensors. I do it with two ADC3 channels with DMA. I use HAL_DRIVERS

I write on a buffer several readings from three sensors by calling:

HAL_ADC_Start(&hadc3);

HAL_ADC_Start_DMA(&hadc3, (uint32_t*)ADC1ConvertedValues, 18);

In ''void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc)''

I call: HAL_ADC_Stop_DMA(&hadc3);

and then HAL_ADC_Start_DMA(&hadc3, (uint32_t*)ADC1ConvertedValues, 18);

when I need another sensor reading.

The problem is that ADC1ConvertedValues[] has always the same information (only the first readings are ok). The others make no effect in ADC1ConvertedValues[].

Any idea why?

Many thanks in advance.

Some code of important functions:

void MX_ADC3_Init(void)

{

ADC_ChannelConfTypeDef sConfig;

/**Configure the global features of the ADC (Clock, Resolution, Data Alignment and number of conversion)

*/

hadc3.Instance = ADC3;

hadc3.Init.ClockPrescaler = ADC_CLOCKPRESCALER_PCLK_DIV2;

hadc3.Init.Resolution = ADC_RESOLUTION12b;

hadc3.Init.ScanConvMode = ENABLE;

hadc3.Init.ContinuousConvMode = ENABLE;

hadc3.Init.DiscontinuousConvMode = DISABLE;

hadc3.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;

hadc3.Init.DataAlign = ADC_DATAALIGN_RIGHT;

hadc3.Init.NbrOfConversion = 3;

hadc3.Init.DMAContinuousRequests = DISABLE;

hadc3.Init.EOCSelection = EOC_SINGLE_CONV;

HAL_ADC_Init(&hadc3);

/**Configure for the selected ADC regular channel its corresponding rank in the sequencer and its sample time.

*/

sConfig.Channel = ADC_CHANNEL_9;

sConfig.Rank = 1;

sConfig.SamplingTime = ADC_SAMPLETIME_15CYCLES;

HAL_ADC_ConfigChannel(&hadc3, &sConfig);

/**Configure for the selected ADC regular channel its corresponding rank in the sequencer and its sample time.

*/

sConfig.Channel = ADC_CHANNEL_14;

sConfig.Rank = 2;

HAL_ADC_ConfigChannel(&hadc3, &sConfig);

/**Configure for the selected ADC regular channel its corresponding rank in the sequencer and its sample time.

*/

sConfig.Channel = ADC_CHANNEL_15;

sConfig.Rank = 3;

HAL_ADC_ConfigChannel(&hadc3, &sConfig);

}

void HAL_ADC_MspInit(ADC_HandleTypeDef* hadc)

{

GPIO_InitTypeDef GPIO_InitStruct;

if(hadc->Instance==ADC3)

{

/* USER CODE BEGIN ADC3_MspInit 0 */

/* USER CODE END ADC3_MspInit 0 */

/* Peripheral clock enable */

__ADC3_CLK_ENABLE();

/**ADC3 GPIO Configuration

PF3 ------> ADC3_IN9

PF4 ------> ADC3_IN14

PF5 ------> ADC3_IN15

*/

GPIO_InitStruct.Pin = GPIO_PIN_3|GPIO_PIN_4|GPIO_PIN_5;

GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;

GPIO_InitStruct.Pull = GPIO_NOPULL;

HAL_GPIO_Init(GPIOF, &GPIO_InitStruct);

/* Peripheral DMA init*/

hdma_adc3.Instance = DMA2_Stream0;

hdma_adc3.Init.Channel = DMA_CHANNEL_2;

hdma_adc3.Init.Direction = DMA_PERIPH_TO_MEMORY;

hdma_adc3.Init.PeriphInc = DMA_PINC_DISABLE;

hdma_adc3.Init.MemInc = DMA_MINC_ENABLE;

hdma_adc3.Init.PeriphDataAlignment = DMA_PDATAALIGN_WORD;

hdma_adc3.Init.MemDataAlignment = DMA_MDATAALIGN_WORD;

hdma_adc3.Init.Mode = DMA_CIRCULAR;

hdma_adc3.Init.Priority = DMA_PRIORITY_MEDIUM;

hdma_adc3.Init.FIFOMode = DMA_FIFOMODE_DISABLE;

HAL_DMA_Init(&hdma_adc3);

__HAL_LINKDMA(hadc,DMA_Handle,hdma_adc3);

/* USER CODE BEGIN ADC3_MspInit 1 */

/* USER CODE END ADC3_MspInit 1 */

}

#stm32f4 #adc #dma

jmiguelg · ‎2015-07-22

Posted on July 22, 2015 at 09:00

Hello,

The problem is that after HAL_ADC_Stop_DMA is executed in

void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc)

{

HAL_ADC_Stop_DMA(&hadc3);

}

next calls to HAL_ADC_Start_DMA(&hadc3, (uint32_t*)ADC1ConvertedValues, 18);

do not fire the ADC/DMA work so that the interrupt HAL_ADC_ConvCpltCallback is never called again.

Any idea why ?

Best Regards,

Jorge