Re: minimilltask V/S bridgeporttask

["Joel Jacobs" <jj-at-netexp.net>]

----- Original Message -----
From: "Jon Elson" <jmelson-at-artsci.wustl.edu>
To: "Multiple recipients of list" <emc-at-nist.gov>
Sent: Tuesday, May 16, 2000 3:07 PM
Subject: Re: minimilltask V/S bridgeporttask


>
> Ahh, wonderful.  I have a variable speed drive that takes 0-10 V
(unipolar)
> signals for speed control.  So, when you are working on this, please think
> about a .ini file parameter so that the speed can be made unipolar, and
> the direction set with the forward and reverse bits.  Looking forward to
this!
>

Something I've been seeing on most of the microprocessor controlled consumer
electronics when they need a cheap-n-dirty analog voltage is to output a
variable duty cycle frequency on a port pin and use an RC filter.  Of course
the response time would not be that great but I think it would work fine for
stuff like spindle speed control.  You could generate a 0-5v unipolar output
with one parallel port bit, one resistor and one cap - and a few CPU cycles
:)

Joel