STM32-G071 ADC measurements

[JBH]

Hello

I am currently working with the STM32G071 microcontroller and encountering an issue with the ADC when using a specific configuration.

Here is a summary of my setup:

• ADC configured in "Sequencer fully configurable" mode

• Scan conversion mode: Disabled

• Discontinuous conversion mode: Enabled

• Oversampling: Enabled (Ratio = 8x, Right bit shift = 3)

When I measure two or more channels in this setup, the last channel in the sequence shows an incorrect result, with an error of about 30%. The earlier channels in the sequence seem to be accurate.

I would like to understand if this behavior is expected due to the chosen configuration, or if there is a workaround or recommendation to avoid this issue. Any guidance or clarification would be greatly appreciated.

Thank you in advance for your support.

Best regards,

[TDK]

Increase sample time to max for most accurate results. High impedance signals will need more time.

How to optimize the ADC accuracy in the STM32 MCUs - Application note

Hard to say more without seeing the setup. No reason that you should expect the last channel to be incorrect.

[JBH]

Hello,
First of all, my measurements work perfectly without oversampling or in "not fully configurable" mode.
I'm having an issue with the last measurement when I choose the "fully configurable" mode with oversampling.

I’m attaching the .ioc file and my main.c 

Thank you for your help.