VB is a great tool to build a quick user interface, but this is no simple task to do it correctly. The meat of a cnc controller though has to be a precise timed IO routine. MACH3 for example has a minimum 25khz kernel, and can have up to a 100khz kernel. Someone familiar with Windows Internals and drivers is really needed to build that kernel. My educated guess is the kernel timing needs to output step/dir pulses based on a buffer the background builds as it's intrepreting G-code and doing trajectory planning. That needs to be a low latency timed event. At 50khz that's an update every 25us which doesn't seem like a real difficult task, but you don't want that 25us wondering from 50us one iteration to 15us the next iteration. The emc guys have some applicable documentation:
http://www.linuxcnc.org/content/view/42/13/lang,en/
http://wiki.linuxcnc.org/cgi-bin/emc...HardwareDesign
Trajectory planning:
http://wiki.linuxcnc.org/cgi-bin/emc...imple_Tp_Notes
Phil, Still too many interests, too many projects, and not enough time!!!!!!!!
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