Ported to C

[larsks]

I don't know if this is of interest to anyone, but I've ported this to straight C so that I can use it with avr-gcc rather than Arduino. You can find the fork at https://github.com/larsks/FastPID. Since there's nothing AVR-specific in the code, I've also added some simple unit tests that compile on the host.

I have not yet ported the example code: because the standard avr-libc environment has neither millis()/micros() nor any serial support I'll have to add in some additional code to make the examples work as intended.

The new unit tests are run by travis for pull requests and commits.

[mike-matera]

Wow! I'm so flattered. Thanks.