Richard,
Yes, the net contains a ton of information on PID. I found a couple
of good pages on the subject - one I liked in particular gave good
examples of PID and PI etc. Like dummy, I didn't bookmark it so I
have to find it again.
I am looking over that Atmel app note and that looks VERY
interesting. I don't know if I would use that discrete for this
project (as I need to learn a bit more about it) but when I start
experimenting with servos, that looks like the ticket!
Chris
PID control of motors is a favorite topic for Google. I just did a
search on 'pid control of dc motor' (without the quotes) and came
up
with a bunch of relevant hits.
There is the Atmel app note AVR221 'Discrete PID
controller'.
pdf
The source code is available and is suited to all AVRs according to
Atmel
It is writen in C but the DOXYGEN documentation is excellent.
I would start with this and see where it goes.
Richard