I recently hacked up a controller, just to see what was involved. The switches were easy to handle, but the joysticks were a pain. I had to replace the joystick pots with 100K-ohm versions. The new pots didn't have exactly the same footprint as the old, so it took some effort to get it back together.

Anyway, this controller also has a digital D-pad which is essentially four contact switches (fwd/rev/left/right). I was thinking about changing the software to use the D-pad instead of the joysticks. The big problem is the lack of speed control. The analog joysticks provide about 128 speed gradients in any direction, whereas a digital interface provides two (on or off). I could, of course, use some other buttons to select speed, but I'm not going to get anywhere near 128 different speeds. And I'm guessing it wouldn't be as intuitive to the operators.

I'm wondering if any teams have used a strictly digital interface to control their robots? I'm not talking about digitally encoding the joystick positions; I'm thinking about getting rid of the joysticks altogether.