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From:	Mitch Davis <mjd+geda-user AT hackvana DOT com>
Date:	Fri, 19 Dec 2014 10:21:55 +1100
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Subject:	Re: [geda-user] Nema 23 stepper motors
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On Fri, Dec 19, 2014 at 8:10 AM, Dave McGuire <mcguire AT neurotica DOT com> wrote:
>
>   I was about to suggest the same thing.  Real stepper controller ICs
> have been around for 40+ years; it has really never been a good idea to
> bit-bang it with a processor.  Today's stepper controller chips are
> very, very impressive.

Indeed.  They do stuff so you don't have to.

Avayan has a great series of articles about the TI88xx range of
stepper chips.  Here's one which covers the differences across the
range, and why you'd choose one model over another:

  http://ebldc.com/?p=355

Here's an amusing two-part "interview" with the TI8833:

  http://ebldc.com/?p=264
  http://ebldc.com/?p=271

If you'd rather watch a video:

  https://www.youtube.com/watch?v=F2sbq4ZYhwA

One big takeaway from that video is hearing the difference in noise
between microstepping and no microstepping.  Notice how incredibly
loud it is when microstepping is disabled.  If you're trying to drive
H-bridges yourself, the result you're going to get is only ever going
to be as good as that incredibly noisy non-microstepped mode, and
possibly worse.  Plus you don't have all the regulation and protection
features.  Use a chip!

Mitch.

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