Re: gEDA-user: gschem/gnetlist potentiometers

[sdb@cloud9.net (Stuart Brorson)]

gEDA users --

I checked my netlister.  As it turns out, VARIABLE_RESISTOR is not a
built-in DEVICE type.  This was expected.  However, the refdes "R" is
also not recognized in "write-default-component".  Ooops. . . .

I'll fix up the netlister and post the new version soon.  Until then,
a work-around is to just replace the pot with a resistor, and make
some sort of text annotation saying that it may be varied.  Ya gotta
use gschem to vary the value anyway . . . and yes, this
sux, but at least you can simulate. . . .

Stuart

> 
> [ . . . . .]
> > >new pots give similar results. gschem is version 20030525, and gnetlist
> > >is too.  The .sch snippet is:
> > >
> > >C 30200 58300 1 90 0 resistor-variable-2.sym
> > >{
> > >T 29550 58900 5 10 1 1 0 0
> > >refdes=R18
> > >T 29700 58500 5 10 1 1 0 0
> > >value=1M
> > >}
> > 
> > 	The above netlisted fine for me (using the geda test backend),
> > but when I used the spice-sdb backend, I got the below message.
> > 
> [ . . . . .]
> > 
> > >Found unknown component.  Refdes = R18
> > >
> > 
> > 	Note, the pot did get into the netlist, but most likely not in
> > a form that your spice simulator expects.
> > 
> > 	Just based on looking at the backend code, spice-sdb doesn't
> > know anything about "VARIABLE_RESISTOR"s.  Is there a workaround or
> > solution for this Stuart?  Thank you.
> > 
> Hmmm. . . .  the netlister looks first at the DEVICE attribute, which
> in this case looks like "VARIABLE_RESISTOR".  If the dispatch section
> of the Scheme code doesn't recognize the DEVICE attribute, then it
> tries to figure out what to do based upon the refdes.
> 
> VARIABLE_RESISTOR is not a built-in DEVICE type, which is why you get
> this message.  It probably did the right thing anyway 'cause the
> refdes was "R18".  Did you see a R18 card in the SPICE deck?  
> 
> Anyway, I will fix the Scheme code to include this DEVICE type,
> and post the fixed code on my website in a day or two.  Please be
> patient -- I am traveling right now so I don't always have immediate
> access to the net to post patches.
> 
> Also, I am interested in hearing about other devices which don't
> netlist correctly, or complain about "unknown components"; I am happy
> to include them in the dispatcher.
> 
> Stuart
>