> Hmm... I've looked at your web page and I must say that encoder sure does
> have a wierd coding sequence, doesn't it.... :-)  Methinks I'll have to
> brainparse that one a little bit...

It's probably using Gray code to encode the shaft angle of the encoder.  Gray
codes have the property that only one bit changes in going from one state
to the next.  This prevents errors, since you don't have clock new
samples to make sure you've got a stable value; you need only look for
a valude which differs from the previous one.  You don't get this same
effect from a binary-encoded ripple counter.

There's a simple algorithm using XOR operations which can be used to
translate between gray code and "normal" binary encoded values.  Actually,
it's a pretty simple circuit as well using XOR gates.  I'd refer you to
"The Art of Electronics" by Horowitz and Hill.  ISBN 0-521-23151-5, but
I know there's a new edition subsequent to this one.

louie