Pullup/pulldown internal resistors ESP32

[budman1758]

Are the pullup/pulldown internal resistors in the ESP32 supposed to be working? I can't seem to get them to work at all in either direction. Trying to get push buttons to work and I get nothing. Tried on several different general purpose GPIO and getting nowhere. Setting state at hardware page and rebooting doesn't seem to do anything. No matter what all I'm getting is a about .4 to .5 volts unless its tied direct to ground or power. I can install pullups/downs no problem but I was expecting the internals to work.

Am I all wet here or ??

[TD-er]

Not sure if there is a difference between input or output mode regarding pull-up or -down resistors.
But I would expect that setting a pull-up or -down resistor active would force the pin to a specific level.
Unless there is another resistor present, like there is for sure on GPIO-12 (do not use that one as input where it can be at any level during boot !!!) as the level on that pin during boot determines the voltage of the flash chip.
So depending on the used flash chip, it is either low or high at boot.

This means you could verify on that pin whether it has a more specific state than 0.4 or 0.5V.

GPIO 16 and 17 are a bit strange here as they tend to show a very high frequency of 80-ish MHz, which may appear as just about any voltage between 0 and 3V3 on a multimeter.
They can be used, but that's their boot state (on some builds)

The ESP32 does have several "strengths" of pull-up and -down resistors, but right now I have not yet played with using different strengths.
It is also possible to use neither and thus create an "open drain" pin. Have not yet played with those.

The default resistance of those pull resistors is roughly 50k - 80k if I'm not mistaken, so it isn't that strong.