Re: [CAD_CAM_EDM_DRO] Re: step pulse timing resolution

Matt Shaver wrote:

> > Nope, can't be done by a CPU. 8000 Hz is a period of 125 uS, 7999
> Hz is
> > a period
> > of 125.016 uS, or only a difference of 16 nS! You SURE can't
> interrupt
> > a Pentium - ANY pentium - every 16 nS!
>
> OK, I admit I should have thought this through a little more. Of
> course I
> don't need that fine a granularity, I just need finer granularity than
> we've
> been able to achieve thus far with software only solutions. The point
> I was
> trying to make was that achieving maximum pulse rates isn't really the
>
> problem with software based stepper control. I would like to know what
> sort
> of granularity Art thinks he can get out of his VXD solution, and how
> he's
> going to do it.

Well, using a timer, it is easy to do arbitrary granularity for ONE
axis, but it gets
into big trouble with 2 or more! What if you have two axes that need
pulses that
will come out very close together? Of course, you can have some code
that
figures out when this is going to happen, fudges the pulses at the same
time, and then
compensates later. The more axes, the more fudging will go on.

Jon