Re: gEDA-user: footprint=none

[Eric Winsor <ewinsor@srl-sdl.org>]

Bill Wilson wrote:
> OK, I've put up a new gsch2pcb tarball:
>
>     http://web.wt.net/~billw/gsch2pcb/gsch2pcb-1.3.tar.gz
>
> and tuned the footprint handling to make gsch2pcb usage slightly more
> convenient:
>
> 1) For symbols that have no footprint attribute give a warning
>    and don't write an unfound package line into the output PCB file.
>    However, if any such symbols have net connections they will be in the PCB
>    netlist.
>
> 2) For symbols that have the attribute footprint=none give a warning
>    and don't write an unfound package line into the output PCB file.
>    So having the "none" footprint can serve as a generic place holder
>    where multiple real footprints are candidates and the gsch2pcb
>    warning serves as a reminder that one of them should be chosen.
>
> 3) New option "empty-footprint name".  If specified (probably in a project
>    file), then for symbols that have a footprint set to that name no warning
>    is given (unless the verbose option is given) and nothing is written
>    into the output PCB file.
>    This just gives a convenient way to have symbols in a schematic which
>    will not be mounted on the PC board and to shut up gsch2pcb warnings
>    about it.  However, if net connections are made to these symbols, they
>    will be in the PCB netlist and PCB will warn if the netlist is loaded
>    and never consider the layout complete.
>    So, maybe connections to such parts could be drawn with a graphical
>    line and not a net?
>
>    If "none" is specified as the empty-footprint, eg. the project file has:
>        empty-footprint none
>    then there are no warnings (unless verbose) and "none" will no
>    longer be useful as a place holder as described in 2).
>
> Bill
This should work great.  Connectors that are not designed to be soldered 
directly to a PCB would then continue to be footprint=none.  Then:

1. When they are placed in a PCB schematic they will fall into option 2 
and the designer will then have to pick the pad patern he desires to 
hard wire the connector to.  Here I am assuming that I have to pick 
another footprint in gschem before I run gsch2pcb.  Am I correct?
This allows for none to be used as a place holder too.

2. When they are used in a cable schematic they will be fine because no 
PCB layout is to be done and gsch2pcb will not be used on the schematic 
file.

However, if a third case of the designer placing the cable schematic in 
with the PCB schematic happens then option 3 occures because the 
designer will have to either use graphical lines in place of nets and 
use the "empty-footprint none" option or deal with the PCB warnings of 
an incomplete layout.

This encourages seperating schematics into what will be soldered on the 
PCB and what is not.

Are we thinking the same?


--
Eric Winsor
Stewart Radiance Laboratory
Space Dynamics Laboratory - USURF
Bedford, MA 01730