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

[John Luciani <jluciani@xxxxxxxxx>]

> That looks like really good work.  

Thanks.

> 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?

The Perl module contains two exported subroutines --- footprint_name
and parse_footprint_name. footprint_name creates a footprint name
string from values in a hash. parse_footprint_name populates a hash
with values parsed from a footprint name string. I will be adding more
narrative to the Perl module section (as well as the other sections).

> 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).

> 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.

> 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. 

(* 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...)
> >
> >
>