ADC not working on STM32H750VB

[RaviTheja G]

Hi,

I have a single adc channel where i read the input values through polling, but it always outputs the max value or almost max value (~ 65280+) as long the input voltage value is greater than zero (v0.5+ ). i configured VREF+ to internal voltage reference . The code is appended below :

int main(void)

{

 /* USER CODE BEGIN 1 */

uint32_t aADCxConvertedData = 0;

uint32_t enable = 0;

 /* USER CODE END 1 */

 /* MCU Configuration--------------------------------------------------------*/

 /* Reset of all peripherals, Initializes the Flash interface and the Systick. */

 HAL_Init();

 /* Configure the system clock */

 SystemClock_Config();

 /* Initialize all configured peripherals */

 MX_GPIO_Init();

 MX_ADC1_Init();

 /* USER CODE BEGIN 2 */

   HAL_SYSCFG_VREFBUF_VoltageScalingConfig(SYSCFG_VREFBUF_VOLTAGE_SCALE1);

   HAL_SYSCFG_VREFBUF_HighImpedanceConfig(SYSCFG_VREFBUF_HIGH_IMPEDANCE_DISABLE);

   if(HAL_SYSCFG_EnableVREFBUF() != HAL_OK)

   {

     Error_Handler();

   }

 /* USER CODE END 2 */

 /* Infinite loop */

 /* USER CODE BEGIN WHILE */

 while (1)

 {

   /* USER CODE END WHILE */

    HAL_ADC_Start(&hadc1);

       if (HAL_ADC_PollForConversion(&hadc1, 10) == HAL_OK)

       {

              aADCxConvertedData = HAL_ADC_GetValue(&hadc1);

       }

       HAL_ADC_Stop(&hadc1);

       enable = aADCxConvertedData;

   /* USER CODE BEGIN 3 */

 }

 /* USER CODE END 3 */

}

void SystemClock_Config(void)

{

 RCC_OscInitTypeDef RCC_OscInitStruct = {0};

 RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

 RCC_PeriphCLKInitTypeDef PeriphClkInitStruct = {0};

 /** Supply configuration update enable

 */

 HAL_PWREx_ConfigSupply(PWR_LDO_SUPPLY);

 /** Configure the main internal regulator output voltage

 */

 __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE0);

 while(!__HAL_PWR_GET_FLAG(PWR_FLAG_VOSRDY)) {}

 /** Macro to configure the PLL clock source

 */

 __HAL_RCC_PLL_PLLSOURCE_CONFIG(RCC_PLLSOURCE_HSI);

 /** Initializes the CPU, AHB and APB busses clocks

 */

 RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;

 RCC_OscInitStruct.HSIState = RCC_HSI_DIV1;

 RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;

 RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;

 RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;

 RCC_OscInitStruct.PLL.PLLM = 4;

 RCC_OscInitStruct.PLL.PLLN = 60;

 RCC_OscInitStruct.PLL.PLLP = 2;

 RCC_OscInitStruct.PLL.PLLQ = 2;

 RCC_OscInitStruct.PLL.PLLR = 2;

 RCC_OscInitStruct.PLL.PLLRGE = RCC_PLL1VCIRANGE_3;

 RCC_OscInitStruct.PLL.PLLVCOSEL = RCC_PLL1VCOWIDE;

 RCC_OscInitStruct.PLL.PLLFRACN = 0;

 if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)

 {

   Error_Handler();

 }

 /** Initializes the CPU, AHB and APB busses clocks

 */

 RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK

                             |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2

                             |RCC_CLOCKTYPE_D3PCLK1|RCC_CLOCKTYPE_D1PCLK1;

 RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;

 RCC_ClkInitStruct.SYSCLKDivider = RCC_SYSCLK_DIV1;

 RCC_ClkInitStruct.AHBCLKDivider = RCC_HCLK_DIV2;

 RCC_ClkInitStruct.APB3CLKDivider = RCC_APB3_DIV2;

 RCC_ClkInitStruct.APB1CLKDivider = RCC_APB1_DIV2;

 RCC_ClkInitStruct.APB2CLKDivider = RCC_APB2_DIV2;

 RCC_ClkInitStruct.APB4CLKDivider = RCC_APB4_DIV2;

 if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4) != HAL_OK)

 {

   Error_Handler();

 }

 PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_ADC;

 PeriphClkInitStruct.PLL2.PLL2M = 32;

 PeriphClkInitStruct.PLL2.PLL2N = 129;

 PeriphClkInitStruct.PLL2.PLL2P = 2;

 PeriphClkInitStruct.PLL2.PLL2Q = 2;

 PeriphClkInitStruct.PLL2.PLL2R = 2;

 PeriphClkInitStruct.PLL2.PLL2RGE = RCC_PLL2VCIRANGE_1;

 PeriphClkInitStruct.PLL2.PLL2VCOSEL = RCC_PLL2VCOWIDE;

 PeriphClkInitStruct.PLL2.PLL2FRACN = 0;

 PeriphClkInitStruct.AdcClockSelection = RCC_ADCCLKSOURCE_PLL2;

 if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK)

 {

   Error_Handler();

 }

}

static void MX_ADC1_Init(void)

{

 ADC_MultiModeTypeDef multimode = {0};

 ADC_ChannelConfTypeDef sConfig = {0};

 /** Common config

 */

 hadc1.Instance = ADC1;

 hadc1.Init.ClockPrescaler = ADC_CLOCK_ASYNC_DIV1;

 hadc1.Init.Resolution = ADC_RESOLUTION_16B;

 hadc1.Init.ScanConvMode = ADC_SCAN_DISABLE;

 hadc1.Init.EOCSelection = ADC_EOC_SINGLE_CONV;

 hadc1.Init.LowPowerAutoWait = DISABLE;

 hadc1.Init.ContinuousConvMode = ENABLE;

 hadc1.Init.NbrOfConversion = 1;

 hadc1.Init.DiscontinuousConvMode = DISABLE;

 hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;

 hadc1.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;

 hadc1.Init.ConversionDataManagement = ADC_CONVERSIONDATA_DR;

 hadc1.Init.Overrun = ADC_OVR_DATA_OVERWRITTEN;

 hadc1.Init.LeftBitShift = ADC_LEFTBITSHIFT_NONE;

 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_3;

 sConfig.Rank = ADC_REGULAR_RANK_1;

 sConfig.SamplingTime = ADC_SAMPLETIME_32CYCLES_5;

 sConfig.SingleDiff = ADC_SINGLE_ENDED;

 sConfig.OffsetNumber = ADC_OFFSET_NONE;

 sConfig.Offset = 0;

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

 {

   Error_Handler();

 }

}

any advice would be appreciated, Thank you

#adcpollconversion #adc #stm32h750