> On Jan 10, 2015, at 10:35 PM, Fat-Zer <[email protected]> wrote:
> 
> Hi, I've got a some ideas how to improve some parts if kicad schematics 
> library. 
> 
> 1. A common schematics:
> There are a bunch of compomets with nearly the same schematics but different 
> in pin order/numbers. Also there are several variants of components which are 
> supposed to look the same e.g there are 4 or 5 different OpAmps images. (and 
> as I was told none of them comply current kicad library conventions). The 
> same thing about transistors.
> 
> So it would be nice to have only one image and map it to the concrete 
> component with pin reordering/renaming.

I'm gonna get on my "CvPCB is a disaster" soapbox again.

A component with (nearly) the same symbol but with different pin ordering or 
numbering is a DIFFERENT PART.

The MUCH better solution would be to have different schematic library symbols, 
each with the correct footprint already set in the Footprint field. So the 
common case is the same part which comes in DIP-8 and SOIC-8. Thus your library 
will have, say, an OP134PA and an OP134UA; the former is in DIP and the latter 
is in SOIC-8. Now you place the desired part on your schematic, and everything 
is done for you. You don't have to select the footprint after the fact before 
you do the layout. And if you're really clever, you'll put a vendor (or 
in-house company) part number in the schematic symbol, too, and this ensures 
that the part you place on the schematic puts the correct footprint on the 
board and you order the right part!

Spend the time setting up the libraries in advance, and you do this all once. 
If you go the CvPcb route, you end up doing the same work (part selection, 
symbol/footprint marriage, etc) for every board. That's too much work and 
inevitably results in errors.

Honestly, at every company for which I've worked, there is a company standard 
library which includes vetted parts, and everyone uses only that library. That 
library is set up as I describe above. There's nothing worse than ordering a 
batch of boards where one footprint was used for a part only to receive the 
parts in a different package.


> 2. Different images of the same schematic component.
> There are already such variants for some common components like CP, also 
> there are "small" variants for some components.

Who cares about a symbol variant? Pick the one you prefer and use it. 

> In both such cases we can keep information about the component in single 
> symbol.
> Also as a bonus we can easily support both IEC and US symbols and use it in 
> some other cases.

Why? I think that a lot of advanced users will choose one symbol type and leave 
it at that, and not go the route of switching between one symbol variant and 
another.

> 3. To store pin number of component in additional field.
> Now cvpcb guesses pin number according to the pins displayed on the 
> schematics. Which is wrong if some pins are not connected/not present in the 
> schematics at all.

That problem is solved by not using CvPCB at all, and doing as I suggest above.

> It would be great to store an overall pin number of component too (as an 
> option).

For what benefit?

---------------

OK, I realize that the point is to somehow improve library sharing. I think 
that's an excellent goal. But I also think that at some point, it breaks down. 
Unless all shared libraries adhere to the same standards, inevitably you have 
problems. And I know you can't please everyone, so perhaps the correct way to 
go is to support the hobbyists who don't want to create a complex library 
system for a small design, and the advanced/professional users will build 
company/vetted libraries.



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