I bought a pack of audio taper potentiometers from Amazon used them to build a Teensy powered MIDI controller. Everything is wired and programmed, but I'm noticing that the pots are sending control changes without being touched when in certain positions.
I thought maybe I had a bad ground or something, so I tested one of the other pots by itself with my multimeter and found the same thing - the resistance changes spontaneously when the wiper is in certain positions (near the middle). When the wiper is near either end of its travel the resistance is stable.
Is this normal or did I get a bad set of pots? Are there features built into ResponsiveAnalogRead that can handle this or do I need to write my own filter algorithm?
OK, it seems that the problem was due to using the 5v pin instead of the 3v pin. I noticed that I was only getting half of the range of my pot before the analog read value maxed out; which made me realize that the analog pins must be expecting a lower voltage.
For whatever reason this also fixed the issue of fluctuating values. My guess is that using the right voltage somehow stabilized the pot, because resistance values still fluctuate by several ohms when I measure the pot unpowered with my multimeter.
I suppose this is why pots have a power pin in the first place. I always wondered why they couldn't work with just signal and ground.