Controlling stepper motors w/Propeller?

Oldbitcollector (Jeff)

Concerning Stepper Motors:

I'd like to fill in this gap in my knowledge.. I have access to a couple Darlington arrays, as well
as some common steppers from various PC parts, (floppy drives, hard drives, CDROM steppers)

Can someone direct me toward some good reading in regard to working with steppers?
My initial reading has me a little concerned about current from higher voltage steppers getting
back to my propeller. Is this a valid concern using the darlington array?

I promise a good tutorial on this for others to follow once I can wrap my head around it.

Thanks
OBC

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New to the Propeller?

Getting started with the Protoboard? - Propeller Cookbook 1.4
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Bob Lawrence (VE1RLL)

You can start with this:

http://forums.parallax.com/showthread.php?p=668034

http://forums.parallax.com/showthread.php?p=709406


TMC401_datasheet.pdf
www.semiconductorstore.com/pdf/newsite/trinamic/TMC401_datasheet.pdf


Industrial Circuits Application Note
Drive circuit basics

www.solarbotics.net/library/pdflib/pdf/drive.pdf

stepper- png

http://forums.parallax.com/showthread.php?p=699712


http://forums.parallax.com/showthread.php?p=699044

en.wikipedia.org/wiki/Stepper_motor

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Aka: CosmicBob

Philldapill

OBC,
Yes, there is the chance of some sort of surge going back to the propeller, but fairly unlikely given the fact that you are using such tiny steppers. Regardless, I mess with these quite a bit, and it's a good idea to optoisolate the propeller from the steppers. I'm using some high-speed optocouplers that the propeller drives no problem, then the other side of the optocoupler is fed into a darlington H-bridge and drives my stepper. Unless the stepper somehow creates a back EMF of something like 5KV, the propeller is safe.