Limitless Potentiometers

[dtengineering]

Encoders don't need to be hooked directly to the RC. A little custom circuit using a PIC microcontroller (or other device... consider a VEX RC) can decode several encoder signals.

This means that while you might still use interrupts on the RC to count the rotations, they need not be as frequent as with a direct connection, nor do you need to worry about tracking the timing to determine direction using the RC. Heck, you could even have the custom circuit send a serial data pack of shaft position and velocity to the RC upon request if you really wanted to get creative.

We had a circuit set up like this for the gear tooth encoders a couple years back in the event we needed to use it, and used a similar... although simpler board from banebots with the encoders for the 56mm gearboxes this past year.

Using the banebots boards we had no... well... almost no... problems reading inputs from four encoders. For joints with less than about 270 or 300 degrees rotation, pots work great. (And sliding pots work great, too for linear applications of a few inches or so.... although now that I think of it... why couldn't a long length of nichrome serve as a very long linear pot...?) But in any case for continuous rotation, making an encoder work will be more than worth your time.

Jason