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Precise stepper motor control


#1

Hello Everybody!

I want to try FEZ Domino (already ordered) to substitue some discontinued components in our optical elements printer.
What we generally need is to have a close and easy cooperation of PC and microcontroller, where the FEZ would receive commands from PC, drive XY-moving stage with optical linear encoders, two other stepper motors, read the signal from precise distance sensor and react, finally sending back the confirmation to PC.
Previously most of devices were controlled via CAN bus using PCI-CAN card, but we’d be glad to get rid of it.
What I’d like to ask for is what is the best way for simple, small data amount bi-directional communication with PC via USB. Already read about virtual serial port, but I’d probably prefer some simpler (for software people) way. CAN was creating strange problems sometime, but it will be probably kept between FEZ and stepper drivers (Monopack), unless we find other good controllers working nicely in closed loop with optical encoders…


#2

We are still working on USB client support. Till then you can’t use USB for anything beside debugging. You can use serial for now and when we add USB support you can move ot USB with couple lines of code. We expect next release in July.

Also, because you need precise timing for steppers motors, keep in mind that FEZ is not real time. This is explained in the FAQ and in the book…