Need help getting ADC to work with CubeMX HAL v1.13.0 on STM32L4R5

[mande.274]

Hi,

We are having issues getting the ADC to work on our STM32L4R5 MCU using the CubeMX HAL. We are trying to read VREFINT, but cannot get a value other than 0xFFF to be returned from the ADC. No errors are reported from HAL_ADC_Start, HAL_ADC_PollForConversion, or HAL_ADC_Stop. Can anyone suggest what we are doing wrong? We have tried lots of different options but cannot get a value other than 0xFFF.

The relevant code is as follows:

MCU: STM32l4R5QIIx

Cube FW Package: V1.13.0

Clock:

void SystemClock_Config(void)

{

 RCC_OscInitTypeDef RCC_OscInitStruct = {0};

 RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

 RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};

 /** Configure the main internal regulator output voltage 

 */

 if (HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1_BOOST) != HAL_OK)

 {

  Error_Handler();

 }

 /** Configure LSE Drive Capability 

 */

 HAL_PWR_EnableBkUpAccess();

 __HAL_RCC_LSEDRIVE_CONFIG(RCC_LSEDRIVE_LOW);

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

 */

 RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI|RCC_OSCILLATORTYPE_LSI

               |RCC_OSCILLATORTYPE_LSE;

 RCC_OscInitStruct.LSEState = RCC_LSE_ON;

 RCC_OscInitStruct.HSIState = RCC_HSI_ON;

 RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;

 RCC_OscInitStruct.LSIState = RCC_LSI_ON;

 RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;

 RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;

 RCC_OscInitStruct.PLL.PLLM = 2;

 RCC_OscInitStruct.PLL.PLLN = 30;

 RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;

 RCC_OscInitStruct.PLL.PLLQ = RCC_PLLQ_DIV4;

 RCC_OscInitStruct.PLL.PLLR = RCC_PLLR_DIV2;

 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_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;

 RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;

 RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV8;

 RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

 if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK)

 {

  Error_Handler();

 }

 PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_RTC|RCC_PERIPHCLK_USART1

               |RCC_PERIPHCLK_USART2|RCC_PERIPHCLK_USART3

               |RCC_PERIPHCLK_UART4|RCC_PERIPHCLK_LPUART1

               |RCC_PERIPHCLK_LPTIM1|RCC_PERIPHCLK_I2C1

               |RCC_PERIPHCLK_I2C2|RCC_PERIPHCLK_RNG

               |RCC_PERIPHCLK_ADC|RCC_PERIPHCLK_OSPI;

 PeriphClkInit.Usart1ClockSelection = RCC_USART1CLKSOURCE_SYSCLK;

 PeriphClkInit.Usart2ClockSelection = RCC_USART2CLKSOURCE_SYSCLK;

 PeriphClkInit.Usart3ClockSelection = RCC_USART3CLKSOURCE_SYSCLK;

 PeriphClkInit.Uart4ClockSelection = RCC_UART4CLKSOURCE_SYSCLK;

 PeriphClkInit.Lpuart1ClockSelection = RCC_LPUART1CLKSOURCE_HSI;

 PeriphClkInit.I2c1ClockSelection = RCC_I2C1CLKSOURCE_PCLK1;

 PeriphClkInit.I2c2ClockSelection = RCC_I2C2CLKSOURCE_PCLK1;

 PeriphClkInit.Lptim1ClockSelection = RCC_LPTIM1CLKSOURCE_LSE;

 PeriphClkInit.AdcClockSelection = RCC_ADCCLKSOURCE_PLLSAI1;

 PeriphClkInit.OspiClockSelection = RCC_OSPICLKSOURCE_PLL;

 PeriphClkInit.RTCClockSelection = RCC_RTCCLKSOURCE_LSE;

 PeriphClkInit.RngClockSelection = RCC_RNGCLKSOURCE_PLLSAI1;

 PeriphClkInit.PLLSAI1.PLLSAI1Source = RCC_PLLSOURCE_HSI;

 PeriphClkInit.PLLSAI1.PLLSAI1M = 2;

 PeriphClkInit.PLLSAI1.PLLSAI1N = 20;

 PeriphClkInit.PLLSAI1.PLLSAI1P = RCC_PLLP_DIV2;

 PeriphClkInit.PLLSAI1.PLLSAI1Q = RCC_PLLQ_DIV4;

 PeriphClkInit.PLLSAI1.PLLSAI1R = RCC_PLLR_DIV2;

 PeriphClkInit.PLLSAI1.PLLSAI1ClockOut = RCC_PLLSAI1_48M2CLK|RCC_PLLSAI1_ADC1CLK;

 if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)

 {

  Error_Handler();

 }

}

ADC Init:

static void MX_ADC1_Init(void)

{

 /* USER CODE BEGIN ADC1_Init 0 */

 HAL_ADC_MspInit(&hadc1);

 /* USER CODE END ADC1_Init 0 */

 ADC_ChannelConfTypeDef sConfig = {0};

 /* USER CODE BEGIN ADC1_Init 1 */

 /* USER CODE END ADC1_Init 1 */

 /** Common config 

 */

 hadc1.Instance = ADC1;

 hadc1.Init.ClockPrescaler = ADC_CLOCK_ASYNC_DIV2;

 hadc1.Init.Resolution = ADC_RESOLUTION_12B;

 hadc1.Init.DataAlign = ADC_DATAALIGN_RIGHT;

 hadc1.Init.ScanConvMode = ADC_SCAN_DISABLE;

 hadc1.Init.EOCSelection = ADC_EOC_SINGLE_CONV;

 hadc1.Init.LowPowerAutoWait = DISABLE;

 hadc1.Init.ContinuousConvMode = DISABLE;

 hadc1.Init.NbrOfConversion = 1;

 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 Regular Channel 

 */

 sConfig.Channel = ADC_CHANNEL_VREFINT;

 sConfig.Rank = ADC_REGULAR_RANK_1;

 sConfig.SamplingTime = ADC_SAMPLETIME_247CYCLES_5;

 sConfig.SingleDiff = ADC_SINGLE_ENDED;

 sConfig.OffsetNumber = ADC_OFFSET_NONE;

 sConfig.Offset = 0;

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

 {

  Error_Handler();

 }

 /* USER CODE BEGIN ADC1_Init 2 */

 while(HAL_ADCEx_Calibration_Start(&hadc1, ADC_SINGLE_ENDED) != HAL_OK);

 /* USER CODE END ADC1_Init 2 */

}

Code to read the ADC:

uint32_t ADC_read(void)

{

 uint32_t adc_value = 0;

 hadc1.Instance->DIFSEL = 0;

 HAL_ADC_MspInit(&hadc1);

 HAL_StatusTypeDef res;

 res = HAL_ADC_Start(&hadc1);

 if (res != HAL_OK)

 {

  log_error("failed to start ADC for VREF %d", res);

  return 0;

 }

 res = HAL_ADC_PollForConversion(&hadc1, 50000);

 if (res != HAL_OK)

 {

  log_error("failed to acquire VREF voltage %d", res);

  return 0;

 }

 adc_value = HAL_ADC_GetValue(&hadc1);

 res = HAL_ADC_Stop(&hadc1);

 if (res != HAL_OK)

 {

  log_error("failed to stop ADC %d", res);

  return 0;

 }

 HAL_ADC_MspDeInit(&hadc1);

 log_info("ADC: 0x%08x", adc_value);

 return adc_value;

};