Re: Was Chopper circuit - Now ver 3.2, G298

Yep, you are correct sir, I missed it.

Actually my original comment was about something even further down in
the post about needing a comparator as an external component. There
are PIC's available with comparators built in.

No question, I quite often use an R-2R resistor divider instead of
buying a "real" DAC.

--- In CAD_CAM_EDM_DRO@y..., "Paul R. Hvidston" <paulh@u...> wrote:
> You missed it. Read the rest of that post. It stated:
>
> > > I'm in the middle of a project that uses a PIC to drive a
3776.
> It uses
> > > simple 2% resistors to generate 1/2 - 1/4 - 1/8 steps. No DAC
> required.
>
> Those resisters smell just like a DAC to me ;-)
>
> Regards,
>
> Paul R. Hvidston, N6MGN
> ACKSYS Engineering
> Upland, CA
>
> ----- Original Message -----
> From: "scottdbtnet" <scott@d...>
> To: <CAD_CAM_EDM_DRO@y...>
> Sent: Friday, April 26, 2002 3:06 PM
> Subject: [CAD_CAM_EDM_DRO] Re: Re: Was Chopper circuit - Now ver
3.2, G298
>
>
> > Paul-
> >
> > I can accept that a comparator is a crude A to D, but D to A?
> >
> > --- In CAD_CAM_EDM_DRO@y..., "Paul R. Hvidston" <paulh@u...>
wrote:
> > > Scott-
> > >
> > > But that _is_ a DAC ;-)
> > >
> > > Paul R. Hvidston, N6MGN
> > > ACKSYS Engineering
> > > Upland, CA
> > >
> > > ----- Original Message -----
> > > From: "Scott M. Thomas" <scott@d...>
> > > To: <CAD_CAM_EDM_DRO@y...>
> > > Sent: Friday, April 12, 2002 6:36 AM
> > > Subject: RE: [CAD_CAM_EDM_DRO] Re: Re: Re: Was Chopper circuit -

> > Now ver
> > > 3.2, G298
> > >
> > >
> > > > I have even seen PIC's with comparators built in!
> > > >
> > > > -----Original Message-----
> > > > From: Alan Rothenbush [mailto:beer@s...]
> > > > Sent: Tuesday, April 09, 2002 9:05 PM
> > > > To: CAD_CAM_EDM_DRO@y...
> > > > Subject: [CAD_CAM_EDM_DRO] Re: Re: Re: Was Chopper circuit -
Now
> > ver
> > > > 3.2, G298
> > > >
> > > >
> > > > >
> > > > > Why bother with a PIC for a L297 replacement, unless you
wanted
> > to add
> > > > some
> > > > > rudimentary microstep capability? Would a PIC be cheaper?
The
> > L297 can
> > > do
> > > > > half-step and full-step, but adding microstepping would
require
> > a DAC
> > > and
> > > > > control logic.
> > > >
> > > > I'm in the middle of a project that uses a PIC to drive a
3776.
> > It uses
> > > > simple 2% resistors to generate 1/2 - 1/4 - 1/8 steps. No
DAC
> > required.
> > > > This would be an add-on for DanM's 5A controller.
> > > >