alangarf / picstep Goto Github PK

Firstly thanks for looking at my design, it was started from the ground up for
the community to share and use. I've released all code and designs under GPL,
which means it's free to use for any purpose as long as my copyright is
retained and any modifications are also released publicly. Any commercial
interest must be approved by ME! :)

PICStep is a micro-stepping step motor controller that uses a special set of
driver ICs (LMD18245) to control the motor coils current to such a degree that
you can divide the magnetic steps of a step motor to 1/2, 1/4, 1/8th or even 1/16th
their original size! Of course resolution suffers a little in 1/16th mode as not
all steps are mechanically identical from one to another; the difference
is negligible, but the increased smoothness and efficiency is dramatic!

PICStep uses a single layer board and about 30 components and a few wire links
to make it all happen.

The LMD18245 are rated at 55V @ 3amps but I've not tested it up to that range
and there are special requirements that need to be met to deal with back EMF
at this range. I'd suggest reading the LMD18245 data-sheet (which is available
freely on the net') if you wish to use these drivers at or near this voltage.

I've tested PICStep at 40VDC @ 2.5A without any modification or problems, but your
mileage may vary! :)

I use a simple 24V toroidal transformer and bridge rectifier for my PSU. 24V
RMS works out to about 35VDC when rectified. Plus I've provided massive amounts
of filtering by using a very large electrolytic capacitor to filter out the humps
and bumps. It works very well and can supply my three drivers without a problem.