CAD CAM EDM DRO - Yahoo Group Archive

Re: Whither goest DOS? & FPGAs

Posted by Jon Elson
on 2002-01-25 10:38:54 UTC
Dennis Dunn wrote:

> I am basically just a lurker that has been following this thread. I have
> NO CNC experience whatsoever. So maybe this comment is totally off the
> wall, but ...
>
> What about using FPGAs as a compromise between dedicated fast but
> inflexible HW and flexible but slow SW?

This is what I have done. I am finishing up the last details of a board
that will run 4 stepper motors either with or without encoder feedback,
plus limit and home switches and solid state relays, all from one
parallel port. It uses a digital rate generator for each axis to provide
extremely fine resolution of step rates (time resolution of 100 nS), and
can go from .95 steps/sec to 300,000 steps/sec. (Below .95 Steps/sec,
the algorithm shuts off that channel.) It can also produce 2 quadrature
phase signals instead of the standard step/direction signals, for the
drivers that need these. It supports 16 opto-isolated digital inputs,
as well as 8 positions for Solid State Relays. I don't have a web page
on this, yet, but should have it soon. I hope to have these units
available for $200, but that is still a preliminary price. (The FPGA is a
$30 part, so it will be tough to keep the price down, but I think I
can do it.)

This hardware has already been tested with EMC, and a prototype was
demonstrated at the NAMES show last year. I will have the finished
version there this year, April 27-28 in the Detroit area.

Jon

Discussion Thread

Jon Elson 2002-01-25 10:38:54 UTC Re: Whither goest DOS? & FPGAs