gEDA-dev: Diode symbols in GSchem and PCB

[John Griessen]

This could get implemented sooner if requirement is dropped for communication
between gschem and pcb...  see below...

Peter TB Brett wrote:

> 
> This is something I considered in abstract form over the summer.  Basically, 
> you have a library of "symbols" which you put on your schematic, and a 
> library of "footprints", which you put on your PCB layout.
> 
> A "part" is something that maps the pins on a symbol to the pins on a 
> footprint.  The part may have several variants, and may have metadata 
> associated with it (vendor name/stock id, documentation URL, etc).
> 
> So, for instance, the "STPS2L40U" part would map the pins on the "diode" 
> symbol to the pins on the "DO-214AA" package.

> 
> So:
> 
>  *  Symbols no longer use "pinnumber" or "pinseq" attributes.
> 
>  *  As instantiated, no part is associated.  Attempting to netlist or select 
> slot fails with an error, unless the symbol has "graphical=1".
> 
>  *  A part should be selected.  In this case, the part would be "AD8616".  
> This is still not enough to specify the part fully.
> 
>  *  Now gschem will have read "AD8616.gprt", and the user can select a 
> specific footprint. Having done so, gschem will now allow the user to select 
> slots.
> 
>  *  Combination of symbols by refdes still works, except that all symbols thus 
> combined must have the same part/footprint associated.
> 
> Comments?  This is far too much work to ever get implemented, but I think that 
> it solves the problem.


Comparing this to what I wrote under

ultralight symbol + heavy-but-non-graphical attribute-group-symbol (was:Diode 
symbols in GSchem)

ultralight symbol coexists with old style symbol for backwards compatibility.

part cold be pretty much just a style of symbol.   Having a different filename 
ending is good.


John G