Re: Stepper driver question (slightly O.T.)

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Marv Frankel" <Dcdziner@p...>
wrote:

>
> Guys,
> I have an industrial application that requires only one stepper
> motor, and two photocells. When one photocell goes dark, the stepper
> motor cranks clockwise. When the other photocell goes dark, the
> stepper motor cranks counterclockwise. I'm looking for a fairly simple
> driver. Any suggestions?
>
> Marv Frankel
> Los Angeles

It sounds like your machine has an ON/OFF setting. no signal at all
and it is OFF.

any signal and it is ON.

ONE of the signals ALSO changes state of the DIR pin.

Very simple to do, but the logic and electronics may not be on topic
for the list.

the motor and driver parts seem pretty close though.

What size motor ? how much power do you need ? (have?)

It sounds somewhat similar to Mel Bartels's telescope stuff (CNC to
move a telescope)

Alan is correct that a PIC could handle this, but so could a 555 and a
comparitor.

The comparitor would report when either input went high. and also
report when that one went high so as to necessitate a DIR change.

With the signal, the 555 would just start pulsing away.

If you were running TurboCNC or some such, you could feed those
signals into inputs and run G-Code to make the thing move.

Dave