STM32G030C8TX ADC Issue on PB11 and PB12 Pins

[EGurd.1]

Hello,

I am currently working with the STM32G030C8TX microcontroller and I have encountered an issue while reading analog values through the ADC.

When I attempt to read ADC values from the PB11 and PB12 pins, the measured values are incorrect or unstable. However, when I use other ADC-capable pins on the same microcontroller, the readings appear to be correct and stable.

Because of this behavior, I am unsure whether:

• PB11 and PB12 pins support ADC functionality on this device/package
• There is a configuration issue on my side
• Or there might be a silicon/production-related issue with the chip

I would appreciate it if you could clarify whether these pins are valid ADC inputs on the STM32G030C8TX and if there are any known limitations or special configurations required.

[mƎALLEm]

Hello,

Are you sure there is no other hardware connections to these pins apart of ADC connections?

[AScha.3]

Hi,

errata  https://www.st.com/resource/en/errata_sheet/es0486-stm32g030x6x8-device-errata-stmicroelectronics.pdf

shows no problem with  PB11 and PB12 pins , 

the pins should give correct ADC values :

You choose in15 and 16 ?

[Saket_Om]

Hello @EGurd.1 

Please check if the clock for GPIO PORT B is enabled.

[Ozone]

> I am currently working with the STM32G030C8TX microcontroller and I have encountered an issue while reading analog values through the ADC.

And what hardware you are talking about, a commercial board (like Nucleo), or a custom design ?

> When I attempt to read ADC values from the PB11 and PB12 pins, the measured values are incorrect or unstable.

What makes you think that, i.e. what do the results look like ?
Have you tried Vin=0V and Vin=Vref on this inputs ?

 

[EGurd.1]

As you see on CUBEMX, it can not determine channel number only if PB11 or PB12 is choosen.
Even though CUBEMX cant determine channel number, I rewrite sconfig.channel as for channel 15 (PB11) and channel 16 (PB12).

 

/** Configure Regular Channel
 */
 sConfig.Channel = ADC_CHANNEL_16;
 sConfig.Rank = ADC_REGULAR_RANK_1;
 sConfig.SamplingTime = ADC_SAMPLINGTIME_COMMON_1;
 if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK) {
 Error_Handler();
 }

 I tried ADC poll for conversion for channel 10,11,15 and 16 seperately with this code. And the result was: channel 10 and 11 works perfectly. Even though channel 15 (PB11) is always 460 (12 bit adc max 4095) and channel 16 (PB12) is always 55. I already see voltage changes with ossiloscope on these pins, i can't see on debug.

HAL_ADC_Start(&hadc1);
 while (1) {
 if (HAL_ADC_PollForConversion(&hadc1, 100) == HAL_OK) {
 adcValues[0] = HAL_ADC_GetValue(&hadc1);
 }
 }

 

[waclawek.jan]

Measure voltage (using multimeter or oscilloscope) directly at the given pins.

Read out GPIOB_MODER register content and check if PB10/PB11 are set as Analog.

[EDIT] see my post below

JW

 

[waclawek.jan]

Oh, so you probably attempt to use the fully configurable sequencer mode (I don't know how is it called in Cube/CubeMX, I don't use Cube). That has this limitation, as documented in the RM (and CubeMX attempted to prevent you from going against it):

JW

 

[AScha.3]

Hi,

the old CHSELRMOD    problem....see :

https://community.st.com/t5/stm32-mcus-products/stm32g030-adc-issue/m-p/316178

https://community.st.com/t5/image/serverpage/image-id/29730iA12D932F17F7387E/image-size/large?v=v2&px=999

vs

https://community.st.com/t5/image/serverpage/image-id/29729iDBD05E8CD83CFBA7/image-size/large?v=v2&px=999

So set CHSELRMOD = 0 , to select ch 0...18 .