Regarding the issue that the chip using STM32G431CBU6 cannot be read by ADC

[JingtaiChen]

Regarding the issue that the chip using STM32G431CBU6 cannot be read by ADC
Hello, recently I have been using the STM32G431CBU6 and found that the ADC cannot be used in the Arduino environment. The read value is always 0. I don't have any other computer to test it, but I tried to use CubeIDE to read the same pin. CubeIDE has no problem and can read the value. Here I attach my program.
‘’
HardwareSerial Serial1(PA10, PA9);

void setup()
{
Serial1.begin(115200);
// analogReadResolution(12);
}

void loop()
{
Serial1.println(analogRead(PA0));
delay(200);
}
‘’

[fpistm]

Hi @JingtaiChen
Is it a custom board? You used the generic target?
0 is the returned in case of error.
Maybe clock config not correct.

[fpistm]

Looking at the variant of the STM32G431CBU6 and a dedicated B_G431B_ESC1 is supported.
I guess it was tested and ADC functional. Anyway looking at the errata sheet it seems several limitations concern the ADC.

I think it is a clock config issue.
Could you try to add this in your sketch, this will override the default clock config and set the Adc12ClockSelection

 void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {};
  RCC_PeriphCLKInitTypeDef PeriphClkInit = {};

  /* Configure the main internal regulator output voltage */
  HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1_BOOST);
  /* Initializes the CPU, AHB and APB busses clocks */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI | RCC_OSCILLATORTYPE_HSI48;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.HSI48State = RCC_HSI48_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
  RCC_OscInitStruct.PLL.PLLM = RCC_PLLM_DIV4;
  RCC_OscInitStruct.PLL.PLLN = 85;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = RCC_PLLQ_DIV2;
  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_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_8) != HAL_OK) {
    Error_Handler();
  }

  /* Initializes the peripherals clocks */
  PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USB | RCC_PERIPHCLK_ADC12;
  PeriphClkInit.Adc12ClockSelection = RCC_ADC12CLKSOURCE_SYSCLK;
  PeriphClkInit.UsbClockSelection = RCC_USBCLKSOURCE_HSI48;
  if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK) {
    Error_Handler();
  }
}

[JingtaiChen]

The PCB did not use a variant, and the crystal oscillator is 8MHz，I tried your method and called SystemClock_Config() in setup(); Failed to succeed.
PCB using WeACT's G431CBU6, hardware:https://github.com/WeActStudio/WeActStudio.STM32G431CoreBoard/blob/master/Hardware/QFN48/WeAct-STM32G431CxUxCoreBoard_Long_V10%20SchDoc.pdf

[fpistm]

So you used the generic variant. And no need to call SystemClock_Config() in the setup it is called at early stage.
If you used properly the SystemClock_Config I provide then I guess the best way is to debug. As I don't have any board with this mcu I can't help.

[JingtaiChen]

Ok. Thank you for the direction you gave. I also think it's a problem with the clock configuration. I'll try again