pic: Small CIM in wheel swerve

[AlexanderTheOK]

Originally Posted by Ether

If your sample time is fast and stable enough that the encoder could never turn 180 degrees from one sample to the next, then "all ya gotta do" at each sample is assume the encoder turned through the shortest angle, and keep track of zero crossings.

Funny you say that. That was the original plan, but Java's timer tasks (as mentioned by 254) are slightly broken on the roborio. We had latencies in code of up to 200ms. We ended up using the FPGA's analogTriggers to keep track.

Since there's really never a need for analogTriggers save for this one strange case, that was broken too. Thank god for the fantastic people at WPI that got it fixed so quickly.

I know sanddrag said that it worked well enough at competition, I have to say the headache caused by this is greater than he may have noted, and took a lot of time out of the season. It's generally just not a good idea to do incremental sensing of anything if it is at all possible to have absolute sensing. Zeroing sensors are a must.