I have this game controller I tried using some months ago. It had 4 joysticks, I made it with an arduino micro.
The problems are: if you deflect one of the joysticks, then the other voltages are affected,,,, and gradually over time, the joysticks "center" drifts. I had a conversation with someone about needing individual voltage supplies so that the joysticks aren't artificially deflected when one of them is actually deflected.
I'm not a terribly good electronics type,,, I'm not really sure the best way to go about fixing it. Right now the usb from the computer powers the device, and the 5v just is what the computer supplies. I would like to keep it powered from USB, so then it's a matter of somehow having 8 stable voltage outputs that aren't going to be affected by eachother being grounded.
That sounds like a small SEPIC converter will be just the thing. They can be gotten for a few $$$. It will regulate the voltage for you. Also check your current, the USB is only good for 1/2 amp max unless it is of the newer variety and your system supports it.
I had a conversation with someone about needing individual voltage supplies so that the joysticks aren't artificially deflected when one of them is actually deflected.
No, most Arduinos have a ratiometric A/D, so absolute voltage is irrelevant
You just have to power the joystick pots from the reference voltage of the Arduino to make them supply independent.
Vref is VCC by default, but that can be changed.
So let us see how
you have powered these pots, and grounded them (equally important).
Post a circuit diagram, and pictures.