Re: gEDA-user: A couple o' questions

[John Doty <jpd@xxxxxxxxxxxxx>]

On Apr 5, 2006, at 1:31 PM, Carlos Nieves Ónega wrote:

> Current pintype attributes are defined in the same way as commercial
> packages I've seen. What I also miss is the "power source" or "power
> sink" pintype. Adding them to the DRC is fairly trivial, and also  
> to the
> docs. Would it be better to have pwr_in and pwr_out pintypes?

Consider linear/lm7805-1.sym. No pintypes. But what should they be?  
Well, maybe OUT should have type pwr_out (if it exists). But what  
about IN? Perhaps pwr_in seems sensible, but then it's most likely  
connected to a diode and a cap: will DRC be able to figure this out?  
Then there's GND, what pintype is that? Remember that it's perfectly  
sensible to connect this to something other than ground, to get 5V  
*relative* to some other potential.

The trouble I see is that the correct pintype needs to be obvious to  
the symbol creator, or chaos results. In pure digital stuff the  
correct pintype usually *is* obvious, but in other applications it's  
not.

John Doty              Noqsi Aerospace, Ltd.
jpd@xxxxxxxxxxxxx