STM32F030C6T6 ADC DMA Circular mode, ADC conversion launched by software.

[Preetpal]

I am using STM32F030C6T6 mcu and i am trying to put its 3 ADC channels on DMA circular mode, but ADC is not initializing in circular mode, pls check below code:

uint16_t adc_buff[3] = {0};  
HAL_ADCEx_Calibration_Start(&hadc);
HAL_ADC_Start_DMA(&hadc, (uint32_t *)adc_buff, 3);

static void MX_ADC_Init(void)
{
/* USER CODE BEGIN ADC_Init 0 */
/* USER CODE END ADC_Init 0 */

ADC_ChannelConfTypeDef sConfig = {0};

/* USER CODE BEGIN ADC_Init 1 */
/* USER CODE END ADC_Init 1 */

/** Configure the global features of the ADC (Clock, Resolution, Data Alignment and number of conversion)
*/
hadc.Instance = ADC1;
hadc.Init.ClockPrescaler = ADC_CLOCK_ASYNC_DIV1;
hadc.Init.Resolution = ADC_RESOLUTION_12B;
hadc.Init.DataAlign = ADC_DATAALIGN_RIGHT;
hadc.Init.ScanConvMode = ADC_SCAN_DIRECTION_FORWARD;
hadc.Init.EOCSelection = ADC_EOC_SEQ_CONV;
hadc.Init.LowPowerAutoWait = DISABLE;
hadc.Init.LowPowerAutoPowerOff = DISABLE;
hadc.Init.ContinuousConvMode = ENABLE;
hadc.Init.DiscontinuousConvMode = DISABLE;
hadc.Init.ExternalTrigConv = ADC_SOFTWARE_START;
hadc.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
hadc.Init.DMAContinuousRequests = ENABLE;
hadc.Init.Overrun = ADC_OVR_DATA_PRESERVED;
if (HAL_ADC_Init(&hadc) != HAL_OK)
{
Error_Handler();
}

/** Configure for the selected ADC regular channel to be converted.
*/
sConfig.Channel = ADC_CHANNEL_0;
sConfig.Rank = ADC_RANK_CHANNEL_NUMBER;
sConfig.SamplingTime = ADC_SAMPLETIME_7CYCLES_5;
if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
{
Error_Handler();
}

/** Configure for the selected ADC regular channel to be converted.
*/
sConfig.Channel = ADC_CHANNEL_1;
if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
{
Error_Handler();
}

/** Configure for the selected ADC regular channel to be converted.
*/
sConfig.Channel = ADC_CHANNEL_2;
if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
{
Error_Handler();
}

/* USER CODE BEGIN ADC_Init 2 */
/* USER CODE END ADC_Init 2 */
}

static void MX_DMA_Init(void)
{
/* DMA controller clock enable */
__HAL_RCC_DMA1_CLK_ENABLE();

/* DMA interrupt init */
/* DMA1_Channel1_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Channel1_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(DMA1_Channel1_IRQn);
}

void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc)
{
HAL_GPIO_TogglePin(GPIOB, LED_Pin);
}

---

Edited to apply source code formatting - please see How to insert source code for future reference.

[Ghofrane GSOURI]

Hello @Preetpal 

First let me thank you for posting.

Could you please share your IOC so i can  check your configuration.

THX

Ghofrane

[Ghofrane GSOURI]

Hello @Preetpal 

ADC peripheral itself does NOT have a "circular mode" setting.

The circular mode applies to the DMA controller that transfers ADC conversion data to memory.

The ADC can be configured for continuous conversion mode or single conversion mode 

hadc.Init.ContinuousConvMode = ENABLE;

 but circular mode is a DMA mode that controls how data is transferred.

    hdma_adc.Instance = DMA1_Channel1;
    hdma_adc.Init.Direction = DMA_PERIPH_TO_MEMORY;
    hdma_adc.Init.PeriphInc = DMA_PINC_DISABLE;
    hdma_adc.Init.MemInc = DMA_MINC_ENABLE;
    hdma_adc.Init.PeriphDataAlignment = DMA_PDATAALIGN_HALFWORD;
    hdma_adc.Init.MemDataAlignment = DMA_MDATAALIGN_HALFWORD;
    hdma_adc.Init.Mode = DMA_CIRCULAR;
    hdma_adc.Init.Priority = DMA_PRIORITY_LOW;
    if (HAL_DMA_Init(&hdma_adc) != HAL_OK)
    {
      Error_Handler();
    }

    __HAL_LINKDMA(hadc,DMA_Handle,hdma_adc);

I performed a test using CubeMX 6.14.1and this is the result that I got :

THX

Ghofrane

[Karl Yamashita]

You need to enable the NVIC in order for the HAL_ADC_ConvCpltCallback to be called