[Thad House]

Originally Posted by thatprogrammer

Okay, I thought you'd simply need to select the 1/4 inch diameter option for the encoders.
When would you use a high cpr vs a low cpr? It seems to me that using a high cpr encoder on a fly wheel might overwhelm the fpga. Any formula to figure out the max possible?

One last question: 971's mentor mentioned their robot featured:

How much % of error can one expect simply using an encoder rather than this set up? Is this set up really necessary or simply a practice that, while good for inspiration and education, is a bit overkill?
Thanks for all the help so far!

High cpr is good for accurate distance, but pulse timing gets pretty jumpy when moving fast. Low cpr allows for smoother pulse timing at high speed. We usually run 256 cpr at 4x for distance, and 6 cpr at 1x, which works great for anything faster then 1000 rpm.


As for distance accuracy, 256 cpr at 4x with a 1.125 inch spool gives an accuracy of 0.003 inches per pulse. That is way more accurate then ever needed, and controlling to that accurate isn't possible.