Andy Pugh wrote: > On 1 August 2010 18:44, Jon Elson <el...@pico-systems.com> wrote: > > >> Our amps DO, indeed, have such a supply. But, this one pulse each way >> thing is needed to clear the shutdown latch in the IR FET driver chip. >> > > Would setting the direction to be opposite to the home direction in > the HAL suffice? > ie, at startup the direction is set one way, then homing sets it the > other way, at which the drive comes up and homing starts. > Hmmm, as long as the PID routine is outputting a non-zero PWM value, then just flipping the direction would sure do it. The PWM pulse needs to be wide enough to make it through the opto-isolator, so somewhere around 5% duty cycle would be ideal, but anything over 2.5% should work (that will give a 500 ns pulse at 50 KHz frequency).
This is essentially what I do in my driver. Jon ------------------------------------------------------------------------------ The Palm PDK Hot Apps Program offers developers who use the Plug-In Development Kit to bring their C/C++ apps to Palm for a share of $1 Million in cash or HP Products. Visit us here for more details: http://p.sf.net/sfu/dev2dev-palm _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
