Speed PID Function

[Ether]

Originally Posted by vamfun

The ring is still required but rather than summing over the whole ring each time the output is updated with the difference between the fresh sample and the oldest sample.

Yup.

Although the bigger question here is, do they really need a filter at all? If they're reading the encoder delta counts every execution cycle and dividing by the cycle period, there's already a whole lotta averagin' goin' on (except at very low speeds).