kicad-developers team mailing list archive

[Lorenzo Marcantonio <l.marcantonio@xxxxxxxxxxxx>]

On Wed, 1 Sep 2010, Brian F. G. Bidulock wrote:

> Do you know of any place where the V2009 (*.plb09) or earlier V6
> (*.plb) file formats are documented?  Or, anybody willing to
> reverse-engineer the format?

No, it's not public. It seems that it's simply a csv with the ipc
parameters encoded in a 'base64-ish' way, nothing else.

> I converted some by hand that I got from gEDA's library.
> Someone did the work to recalculate the lands using the
> IPC-7351 equations with an m4 script.  I hand converted a bunch
> of chip capacitors and resistors to pcbnew modules (pcbnew's
> library chip capacitors were wayyyyy wrong).

I have a lot of discretes in my libs if you want them, all done with ipc
(except SOT23, which our assembly people said preferred with bigger
pads)

> their own *.plb09 files.  (Which begs the question: where did
> they get the format?  Or do they just use LP Wizard or
> something.)

LP Librarian or the LP Calculator itself can generate the plb files. LP
Wizard directly creates a CAD package (only for your licensed CAD, of
course).

> manufacturer's recommended land pattern anyway.  Some do not
> provide IPC-7351 values on their datasheets.

Manufacturers which don't say how big a pin is? Some of the information
the calculator ask are only for library purpose or for trigger some
choice.

> Do you thing that purchasing the standard would shed some light
> on this library format?  Or are the fields in the file just the
> (some of the) parameters that get stuffed into the equations?
> It seems that there are a lot of non-IPC things too (like silk
> screen clearance).

No, they only say how to use the calculator, otherwise you wouldn't buy
the LP Wizard :D Heck, they doesn't even let you download the calculator
because otherwise people didn't buy the standard!

But I think that some experimentation with the calculator would give
insight on the encoding. If they aren't so sick to actually encrypt the
field.

> Maybe all we need is a kind-of-a module-editor wizard that
> uses the calculations from IPC-7[23]51, A, B to guide the
> user and generate (and name) the module under module editor
> which can then be customized from there.  It would still be
> nice for that wizard to read directly a vendor-supplied PLB
> file.
>
> What are your thoughts?

My doc should give all the info needed for doing such a thing. Oh, and
it's only up to the A revision (sorry, we aren't so rich to buy each
update:D). As of the plb file I'll see if I can reverse engineer some of
it.

--
Lorenzo Marcantonio
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