Finally. I have a way to "properly" read unmodified Atari paddle controllers from an Arduino.
That was a lot more complicated than I expected it to be.
And arguably it still isn't finished as the code needs optimising to read all four paddles in a useful way that doesn't lock out everything else!
It would be a /lot/ simpler to hack the controllers and just wire the pots across 5V and GND...
https://diyelectromusic.com/2025/06/16/atari-2600-controller-shield-pcb-revisited/