# ESP32 using Arduino: Internal Pull-ups don't work on GPIO25 or GPIO32

I'm programming a custom ESP32 board using Arduino where GPIO25 and GPIO32 are connected to pogo pins via short 5mm traces and to nothing else. The goal is to poll for a short between them as part of an alignment procedure - pretty straightforward.

The issue is, pinMode(X, INPUT_PULLUP) does not actaully turn on the pullup for either pin; the ADC readings are always floating. Whichever pin I'm using still successfully detects a short when intended, but because It is floating and never pulled high, it causes a lot of false flags. Code below:

    int foo=9999;
pinMode(25, OUTPUT);
pinMode(32,INPUT_PULLUP);
while(foo>0){
Serial.println(foo);
//do other stuff
}

• I typed the code in here directly, that was a typo. Fixed now. I'm reading the correct ADC pin when the described problem happens Sep 19 '20 at 17:29
• This Reddit thread has that IDF library direct approach that may work. I'm about to try it out myself. Reddit Thread on ADC w/ internal pullup Jul 18 at 19:38