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Visitor II
March 11, 2024
Solved

Accurate ADC reading with Bluepill

  • March 11, 2024
  • 3 replies
  • 1647 views

Hello all,

for my DIY Radio Controller (LoRa and STM32F1C8) i am using two joysticks and one poti.

I am reading ADC with the DMA but what i noticed is that the ADC values are not so accurate.
I know with not (professional, expensive) Potis and joysticks this accurate is almost impossible.

With 12 bit resolution the ADC value is (0 - 4095) but the problem is that sometimes the tolerance gets more then 20 or 30 and this value is not ignorable for RC.

P.s. the wires from Joysticks and poti are about 10cm long.

My question :

Is there any idea or way to get more accurate readings from ADC? some filtering or anything else.

Would be using switching regulator as Vcc problematic? 

Please if you have some tipps or ideas it will be appreciated.

Thank you in advance.

    This topic has been closed for replies.
    Best answer by mƎALLEm

    Hello,

    ST resources are only dedicated to supporting genuine ST products. We are not committed to ensuring that clones/fakes products work properly with the firmware we provide.

    We suggest to purchase a genuine products and purchase them from known and trusted distributors.

    Thank you for your understanding.

    3 replies

    Super User
    March 11, 2024

    Hi,

    to get a good value from a pot : just solder cer.cap (100nF) with short wire from adc-input to gnd, on every pot->adc input.

    +

    smps on Vcc is never good idea for supply analog VDD or Vref ; try add/more L-C filter , if needed.

    hamoAuthor
    Visitor II
    March 11, 2024

    Thanks for your reply.

    I will try the cer.cap (100nF).

    Du you suggest any value for the L-C Filter?

    mƎALLEmAnswer
    Technical Moderator
    April 18, 2025

    Hello,

    ST resources are only dedicated to supporting genuine ST products. We are not committed to ensuring that clones/fakes products work properly with the firmware we provide.

    We suggest to purchase a genuine products and purchase them from known and trusted distributors.

    Thank you for your understanding.