AVR-Chat

Lots of folks make encoders. The most common type is the two phase incremental.
Some of those come with a third channel to be used as an absolute "zero" reference.
Sounds like you mamy want an absolute encoder. Bourns has one that outputs seven
bit gray code. Check http://www.bourns.com/ rotary encoders for the EAW part.
Good luck.

Bruce

John Samperi wrote:

> G'day all
> 
> For a few days Yahoo has bumped off the list it seems...
> 
> I posted the following on AVRfreaks so some of you may see this twice.
> I need to know exactly where a stepper motor is positioned at any time.
> By Googling I found some potentiometric position sensors, which I guess
> will do by feeding it into an A/D and reading back the voltage.
> 
> If there is a digital type of sensor that would give me discreet positions
> from 0-255 that would be perfect, and as some of you are geniuses on
> the subject, you may be able to point me in the right direction without having
> to wade some 1600 pages in Google.Basically the program would check where
> the motor is located, find out where it needs to be and issue the correct
> number of pulses to take it there( backward or forward), then check that
> is in fact there. This will be controlling a valve that needs to open a
> certain amount.
> 
> Regards
> 
> John Samperi