On Wed, 2012-05-02 at 20:17 -0500, Jon Elson wrote: > Kirk Wallace wrote: > > > > > > I suspect the magic is in the Xilinx chip programming, so we'll probably > > never know what the magic is. > The G201A and some other drives from years ago used CD4000 CMOS chips and > had all this. Those drives could be deciphered fairly easily. > > I'd like to play with a couple of Pico PWM > > amps on one of my Shizuoka steppers and drive them with FPGA PWM. There > > would not be any current feedback to work with unless I add a pair of > > ADC's though. > > > > On the other hand it might be more productive to start work on fitting > > some brushless motors. > > > Well, just find the motor you want and I have amps for either. It is a > lot simpler > to not have current feedback, but that makes the servo loop a little > less stable. > The fix is to have more encoder resolution, and possibly turn up the > servo update > rate. > > Jon
Other than my servo comment, I meant that I could try to drive my stepper motor with a pair of amps and feed the amps signals that produce the equivalent output of a micro-stepping drive. Only more flexible because the micro-stepping logic is in a LinuxCNC driver. Maybe, one could add a feature to micro-step on encoder pulses. Peter, thanks for the overview of the Geckodrive stepper internal logic. Cool stuff. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
