Im trying to read an analog value with my esp32 and send it over wifi to another esp32. The wifi part works flawless, however when i try to read an analog value form the esp32 its not useable. It jumps around +-100 on range 0-2000. Now i tried to use an external adc, because i heard that some have problems using the internal one with wifi. However i connected it via pins 21 and 22 (SDA Scl) and i have the same problem.

Internet couldnt help me at all, i hope you guys can.

Br Felix

  • Are you running the external ADC from the ESP32's power?
    – Majenko
    May 12, 2020 at 9:57
  • What kind of analog value are you trying to read?
    – StarCat
    May 12, 2020 at 13:26
  • The esp has two internal adcs, of which one does not work with wifi. But the other one is supposed to work and I haven't had any problems so far. Please say something more about your setup. Breadboards can cause problems when wifi is active.
    – Sim Son
    May 12, 2020 at 15:08
  • Ok so muiltiple things caused a bad analogread. Im trying to read a voltage level from 0-3,3v. Only pin 33 Worked and there i had a bit better readings. However still unusable. After i connected the esp32 to an external power supply the value was much better and more usable. Then i implemented some code wich is calcualating an average from 500values. This helped a lot and now im on +-1 on range 0-1000. I still dont know why the external adc didnt work well. I also ran it from external power. Same problem. Best Rg Felix
    – Felix T.
    May 13, 2020 at 11:07


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