Re: gEDA-user: RFC --- Land Pattern (Footprint) Names

[James Cotton <peabody124@xxxxxxxxx>]

> > Also what about creating an alias file so things like 0803 can still
> > be used and simply map over to an IPC name?
> 
> I meant to keep 0803, 1206, etc. as a legal component group name. This
> is an error in the syntax specification (and an omission in the
> component groups section) that I will correct. In the examples there
> is a 0402 and a 2220 (with the optional manufacturer specifications).

Still an aliasing method would allow all of the standard SO20 and
things like that using the (semi)standards on
(http://www.geda.seul.org/docs/current/symbols/node14.html) and
convert them to the IPC names.
 
> > If it generates/could generate the PCB lands, how hard would it be to
> > integrate the perl script into gsch2pcb so that upon generating your
> > pcb it would create the necessary land patterns and put them into a
> > folder.
> 
> I am not sure that I understand your question. Generating the land
> patterns requires a specification that defines pad size, hole size,
> part dimension's etc none of which is contained in a schematic. Using
> a set of rules you could generate *land pattern names*, from a
> schematic, that could be merged into the schematic or passed to
> gsch2pcb as a separate file.

I meant if you had a footprint attribute on your symbol, normally
gsch2pcb searches through the elements-dir parameters for it.  I was
wondering about integrating this script in so that if you had an IPC
footprint name then it could dynamically create the footprints you
need and place them in the new pcb file.

> > Would this create major issues with updating pcb's if that
> > script had a new revision of the script though?
> 
> Possibly. Using incorrect land patterns is a problem that is
> independent of the method used to calculate them.

I guess I was suggesting more if you had a footprint already place on
a PCB and then the script changed the layout of that land it could
break a PCB.  At same time such a change would represent either a
problem in the original footprint or a bug right?

> (* jcl *)
> 
> 
> On 7/8/05, James Cotton <peabody124@xxxxxxxxx> wrote:
> > That looks like really good work.  I wasn't sure exactly what the
> > script does though.  Does it generate a PCB layout file from a name,
> > or create the correct formated IPC strings?
> >
> > Also what about creating an alias file so things like 0803 can still
> > be used and simply map over to an IPC name?
> >
> > If it generates/could generate the PCB lands, how hard would it be to
> > integrate the perl script into gsch2pcb so that upon generating your
> > pcb it would create the necessary land patterns and put them into a
> > folder.  Would this create major issues with updating pcb's if that
> > script had a new revision of the script though?
> >
> > Good work,
> > James
> >
> >
> >
> > On 7/8/05, Xtian Xultz <xultz@xxxxxxxxxxxx> wrote:
> > > Em Sex 08 Jul 2005 15:09, John Luciani escreveu:
> > > >   I have placed a first draft of my land pattern naming convention at
> > > > http://www.luciani.org
> > > > The naming convention is based on IPC-7351.
> > > >
> > > > Please send questions, comments, observations either to the list or to
> > > > (jluciani) *AT* gmail.com
> > > > (as appropriate).
> > > >
> > > > (* jcl *)
> > >
> > > Absolutelly fabulous!!!!
> > > I didnt know that IPC have a free document about it.
> > > I have a doubt: would it be possible in gschem, when I draw a component (like
> > > a resistor) to have multiple footprints associated to it, and when I place a
> > > component and open the Atrib Editor window (I dont remeber the correct name
> > > of this window because my gschem is in portuguese) to choose one of the
> > > footprints of the component?
> > > Or the best should be have one component symbol for every kind of footprint?
> > > (thats because is hard to remeber the correct syntax for a simple resistor,
> > > for example...)
> > >
> > >
> >
>