Hi all, we've talked about using a stepper motor as a rotary encoder.
Check the archives for topics "[EE]: stepper "digital" knob viability"
and "[EE]: "digital" knobs/buttons" from the 26th and 27th of June,
2002. From what I remember/have in my archives, Roman Black actually
managed to get it to work not just using the stepper as a sensor, but
also driving it and getting it to move.

My question is this. I had an idea for a project that would use a
stepper for positioning. So unlike the discussions above, the primary
function of the stepper would be positioning, not sensing. This means I
would have to drive it with enough current to get it to move a load, and
I would likely have to keep one winding energized for holding torque.

Given that circumstance, is it still possible to be able to sense
position using just the stepper as an encoder? Basically I want the
project to sense if someone hits it out of position and how far it's out
of position, then to move back to its proper position. I could use an
optical encoder, but it would cut down on components (and up the cool
factor) if I could use the motor itself.

Ideas?

Josh
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