kicad-developers team mailing list archive

[Lorenzo Marcantonio <l.marcantonio@xxxxxxxxxxxx>]

On Thu, 13 Aug 2015 14:59:49 +0200,
David Novak wrote:

> That's exactly what I told the contract manufacturer, but they insisted
> on a change. With a shape for every reference designator, they had to
> review the shape for every part. With this change, they only have to
> review each shape type.

They actually use the gencad file for something other than pad
probing... and even that usage is made obsolete by D356...

> The change detects when a part is different from the library and creates
> new shapes in the GenCAD file as needed.

Cool:P You had to do a module comparation function to handle that. Not
quite easy to pull (tried that, failed and then you have the current
gencad exporter:D)

> We have some footprints where multiple pins are left un-numbered. These
> pins were represented in the GenCAD file as "none" and the multiple
> "none" pin numbers were causing problems. To prevent the problem, we
> added an enumerated suffix to duplicate pin numbers.

That would be the correct gencad behaviour, fully agree with that. Could
be useful even for named pins which are actually always tied together
(like ground lugs in shielding can).

> I agree completely. Our changes are based on the GenCAD standard.

I hope that gencad die one day or another, like 274D (the external
aperture gerber format). Too bad that there is no agreed substitute;
ODB++ is not free, gencam and IPC350 are almost unheard outside their
designers... maybe because gencam with its 40+ XML schemas is a serious
contender with STEP on the horribly complex kitchen sink file format:P

IPC350 seems sane (the downstream CAM offer substantially uses that
format in core) but AFAIK not established enough to warrant the effort
to code an exporter.

The saddest thing is when the fabricator asks for the "MAX file" (*old*
orcad layout) or "eagle file"...

-- 
Lorenzo Marcantonio
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