gEDA-user: Symbol creation questions

[Dan Sandberg <dan.sandberg.lists@xxxxxxxxx>]

Ok, I opted to add power pins to the symbol because the idea of having 
capacitors floating near the part struck me as odd :)

Some questions about custom components:

1- I copied the Atmega8-1.sym symbol and pasted it on a new page, and 
saved the new page as Atmega8-dan.sym.  Why is my chip zoomed out in the 
add component preview window as compared to the original?  I did a 
translate 0 before saving, and I made my zoom the same as the original 
before saving too.  What else effects how it looks in the preview?

2 - I believe the docs recommend that things generally be snapped to the 
grid.  How come this part's components ( pins, rectangle, ... ) aren't 
aligned to the grid?  

Thanks for the help,

-Dan

John Doty wrote:
> On Jun 5, 2006, at 5:28 AM, Stuart Brorson wrote:
>
> > Here are possible things you can do:
> >
> > *  Redraw the symbol.  Yes, it's a PITA, but part of doing designs is
> > drawing symbols.
> >
> > *  If the symbol has implied power pins (net= attribute), then just
> > stick your decoupling cap on the same schematic sheet and attach it to
> > your power net and GND.  To attach to the power net, just draw a net
> > from the cap, and then give the net a netname= attribute.
>
> Another way is to draw a separate symbol for the power and ground 
> pins, and then give it the same refdes as the powerless symbol. Now 
> you can have a perfectly explicit drawing of power distribution, but 
> avoid cluttering the signal flow drawing with that stuff. This works 
> for most gnetlist back ends, but unfortunately not for spice-sdb.
>
> Stuart, can this be fixed? Your spice-sdb gives the obscure "Invalid 
> wanted_pin passed to gnet-nets [unknown]" error when it sees a 
> duplicate refdes. The reason I ask is that I'm retrofitting my chip 
> design to have explicit power distribution (ah, the joy of changing 
> customer requirements ;-).
>
> John Doty              Noqsi Aerospace, Ltd.
> jpd@xxxxxxxxxxxxx