Problem with ADC on custom board

[IlliaGx]

Hello.
I have a problem with the ADC on the custom board with the STM32WB55 chip. I am using a divider and should get something around 2V, but I always get the maximum value - 4095.
I am using this code that I saw in the ST examples.

 HAL_GPIO_WritePin(ADC_OUT_GPIO_Port, ADC_OUT_Pin, GPIO_PIN_SET);
 HAL_Delay(50);

 if (HAL_ADCEx_Calibration_Start(&hadc1, ADC_SINGLE_ENDED) != HAL_OK)
 {
	 Error_Handler();
 }

 if (HAL_ADC_Start_DMA(&hadc1, (uint32_t*)aADCxConvertedData, BATTERY_ARRAY_SIZE) != HAL_OK) {

	 HAL_GPIO_WritePin(ADC_OUT_GPIO_Port, ADC_OUT_Pin, GPIO_PIN_RESET);
	 Error_Handler();
 }

void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc) {
 if(hadc->Instance == ADC1) {

 if (HAL_ADC_Stop_DMA(&hadc1) != HAL_OK) {
 	Error_Handler();
 }
 HAL_GPIO_WritePin(ADC_OUT_GPIO_Port, ADC_OUT_Pin, GPIO_PIN_RESET);
 uint32_t sum_mv = 0;
 for (uint32_t i = 0; i < BATTERY_ARRAY_SIZE; i++) {
 aADCxConvertedData_Voltage_mVolt[i] = __ADC_CALC_DATA_VOLTAGE(VDDA_APPLI, aADCxConvertedData[i]);
 sum_mv += aADCxConvertedData_Voltage_mVolt[i];
 }

 uint16_t avg_mv = sum_mv / BATTERY_ARRAY_SIZE;

 ubDmaTransferStatus = 1;
 }
}

I put a breakpoint on ubDmaTransferStatus and see what it measures.

I use this same code on the nucleo board by shorting PC1 and PC0 with a wire and seeing normal results, around 3294-3296 mV.

This is not a hardware problem, I measured the output of the divider on the pin with an oscilloscope and saw around 2V. I also tested it on two devices.

I attach a project that works with nucleo, maybe this will help somehow.
Please help me.
Regards.

[raptorhal2]

Step through the program in debug mode and see where it goes wrong.

[IlliaGx]

Hello. Thank you for your answer.
Could you please tell me what I should be looking at? I am already looking at the result in the HAL_ADC_ConvCpltCallback completion callback

[Andrew Neil]

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@IlliaGx wrote:

 custom board with the STM32WB55 chip..

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It's a custom board - so you need to show the schematic.

How to write your question to maximize your chances to find a solution

[IlliaGx]

 

[Andrew Neil]

You need to show the full schematic!