Re: gEDA-user: PCB help . . . .

[Bill Wilson <billw@wt.net>]

On Mon, 22 Sep 2003 12:14:27 -0400 (EDT)
sdb@cloud9.net (Stuart Brorson) wrote:

> My questions:
> 
> *  Where are the footprint names documented?  I have looked at the
> .list and .inc and .m4 files in (what I think are) the various
> footprint directories, but none of the names match those given in
> Dan's HOWTO.  Also, there are zillions of names for each type of part,
> so it is hard to figure out which to use.

I've also looked for docs on this and haven't found any, so I get
a general idea by looking at /usr/X11R6/lib/X11/pcb/pcblib.contents.
This is the m4 library contents and you can look at filenames under
/usr/local/pcb_lib or maybe /usr/lib/pcb_lib to see footprints of
the new "file element" type.  Anyway, back to m4 elements listed
in pcblib.contents, it looks like the second field is element names
so you can get a list of elements with:

    cut -d : -f2 pcblib.contents | sort | uniq

and ignore the trailing "TYPE=" lines.
The problem is that you still don't know how to actually use these
elements as many of them require args, and some names listed are for
aliases you might not like, for example the above shows you the "N"
package when "DIL" is probably preferred.  Unless someone knows of
some real docs on this, it is a mess.

> *  It looks like there are two types of footprints:  those generated
> using an old method (m4?) and those generated using a new method
> (???).  Is this true?  Where is this documented (if anywhere)?  

You'll need to use gsch2pcb instead of gschem2pcb to use these
footprint styles.  See

    http://web.wt.net/~billw/gsch2pcb/gsch2pcb.html

and, again, look at filenames under pcb_lib.

> *  I am used to systems where the different footprints are just
> individual files holding some graphical information.  Here, it looks
> like the footprints are generated by a collection of m4 scripts, and
> one script might generate many different footprints, depending upon
> its calling arguments.  Is this true?  How does PCB know where to look
> when generating the footprints on the screen?

If you use gsch2pcb, then PCB doesn't need to know where to look since
gsch2pcb looks for and adds all the elements corresponding to footprints.
But for footprints you want to manually add, PCB has the m4 element lib
location compiled in and looks for file elements in places specified
by pcb.elementPath: in the Pcb.ad (in /usr/X11R6/lib/X11/app-defaults,
or /etc/X11/app-defaults, depending on your distribution).

> I understand that there is an effort underway to translate a PCB
> document out of Portugese into English.  I would be willing to help
> write or edit this doc if I could see an early copy which would help
> me get "over the hump" with PCB.  Just point me to the location where
> the drafts live.
> 
> Thanks for any and all help,

I'm probably two or three days from putting up a tutorial on using
gsch2pcb with gschem and PCB.  I really think it will be helpful
with the "hump" problem.

Bill

--------
Bill Wilson <bill@gkrellm.net>
http://gkrellm.net