Re: hardware driver

[Jon Elson <jmelson-at-artsci.wustl.edu>]

Hello, all,

I have essentially given up on Eric getting any more done on the
driver for the new parallel port motion control hardware.  I wish
he had the decency to just tell me he couldn't do any more.  I
can understand that.  He did, however, do a great job of getting
me a bunch of routines that replace the STG routines and would
compile under a standard makefile for testing these components
as user-mode code.  I had to take it from there, and now have
it pretty well running using the diag program as was used with the
STG driver.

If somebody could give me some help in making the transition
from here to actually integrating the DAC and encoder sections
with EMC, and faking out the digital I/O which doesn't exist yet,
I'd be very greatful.  I think there is more hacking needed in
makefiles than in the actual code at this point.

I had a few quirks that showed up when I put the encoder and DAC
boards together on the PPMC motherboard, but I have understod
the source of the trouble, and quick patches verify this.  The first
motherboards will need some hackery to make things work
properly, but there's plenty of room for a few wires.
I made a quick and dirty little program that simulates the EMC
servo control loop by reading and displaying the encoder count
on 4 channels, and sending the least significant 16 bits of that to the
respective DAC channel.

Jon