I just finished my box for the Axoloti, which has 14 (10K) Potentiometers and one rotary switch as analog inputs (the analog switch connected following Johannes' instruction here).
The GND and VDDAs (outer pins) for all those analog controllers are connected to each other and go centrally to one VDDA and GND on the board, while the middle pins each go to the board. Everything works as expected, except three of the pots do not, behaving instead as though they're not connected at all.
I checked all connections between pots and to the board, and they all work. The pots are ok, too (checked with Multimeter). There is also 3.2 V between the outer pins of the three pots as expected. Changing the gpios doesn't help either, so it's something about these particular three pots.
What is odd, and only occurs with these three, though, is that there is voltage between the middle pin and the VDDA, but not between the middle pin and GND (on two of them), and, respectively, voltage between middle pin and GND, but not VDDA (on the third). On all other, functioning pots, there's voltage between either one of those, amounts changing with pot position, as I think there should be.
So I suspect this has something to do with why they do not deliver the right info to the analog gpios, but I am at a loss as two why that should be, or, more importantly, how to correct it. Is there a limit to how many pots should connect to the same VDDA or something like that?
Any help will be really appreciated.