Anne Ogborn wrote:

> What's 'relatively fast'?
>
> How fast is the wheel turning?  If you have a 400 slot optical encoder
> on a turbine shaft, a PIC won't cut it. If it's on a knob being turned
> by somebody, it will.
>
> An optical encoder typically puts out "quadrature" -two 10101010101 streams th
at
> are 90 degrees out of phase. By checking which is leading, you know which way
the
> wheel moved.
>
> What the signal looks like, wheel turning ccw:
>

<snip>

"Relatively fast" would be someone turning a shaft.  Actually, all I
only need is
about 120 degrees span and about a tenth of a degree resolution.  I've
read about the
poorly shaped outputs of these things and am wondering if I can update a
display fast
enough.

Thanks for the reply.

Jon