Hi Bernd,
? Thanks for your responses.? I went through the KiCAD posts looking for discussions on grid sizes; it looks like EESchema will retain the mil grid (in all the posts I can find regarding grids, the devs say they have no plans to change the schematic grid since there is no great advantage to this). So I was mistaken; symbol standardization can go on with the mil grid.? This does result in larger symbols though since nodes are at 2.54mm rather than 2.0mm.
________________________________
From: Bernd Wiebus <bernd.wiebus@...>
To: kicad-users@...
Sent: Tuesday, June 12, 2012 4:08 AM
Subject: Re: [kicad-users] Re: Comments About Eeschema
?
Hello Cirilo.
Have you seen Bernd Wiebus's EN60617 (aka IEC60617) kicad library?
If it's correct (I have no reason to doubt that but I have nothing to
check it against, though maybe those Chinese sites are worth exploring)
I guess it would be a good place to start, though personally I find
Bernd's symbols too big.?? Is it the latest standard?
??Some of those symbols do comply with the IEC standard and many that don't do comply with older standards.
If this is, it is marked by the symbols name. Thomething with "old". In
this cases, there are existing two symbols, one for the old standard,
ans one for the new. This is because here most people like the old timed
full black inductance boxes.....
But there are some "needfull things" among those EN60617 symbols, wich
are not EN60617, but this are normally not electronic devices, with the
exeption of "wire bridges".
If desired, i could split this library in two and purify the EN60617
part.
I suspected some people wanted older symbols; personally I think some of the older symbols are prettier and for me they're easier to understand. It would be good to keep the EN60617 compliant symbols in their own directory+library since that will help a lot with the standardization process and in the future if people have requirements to use a specific symbol set it makes it easier for them to comply.
Anyway, as I said, what's important is that people can read the schematics.
I think Bernd's symbols can't really be shrunk much more;
EN60617 makes no statements about the aspect ratio of symbols (means
wether a resistor "box" is lean or fat and something like this). And for
kicad i should not go away from the 50-50 raster for easily drawing
circuits without jumping into the engin room and changing the raster.
That's one of the situations common with standards (lack of implementation details).? In this case it just means choosing your own settings based on what looks good and is easy to read; the grids used might impose some restrictions on what you can draw and that may be one reason the aspect ratio is not specified.
I'd say his symbols are OK, certainly usable,
but most can be improved (for example, the purists will howl about the line connecting the vertices of
the inductor symbols - and rightly so). The problem as usual is time; building a good symbol set takes
an awful lot,
Yes. This is a time problem. But there are some other points counted
against creating a "new" library. And this is to be compatible with
older versions of this library. If i change them to much, people will
see gaps if the new symbols do not fit to the same connections as the
old do.
This may not be an issue for an experinenced kicad user, but for an
necomer.
I agree 100%.? I was thinking there would be a metric and a mil set of symbols, but for now it looks like EESchema will retain the mil grid.
??and at this point in time I'd recommend waiting for KiCAD to go metric (internal units = nanometers)
before spending time building up standard symbols. However, if you look at the symbols which come with KiCAD,
very many (I can't say 'most' because I haven't looked through the set and counted the bad ones) are not only
non-compliant with the latest IEC specifications, but I don't recognize the symbols as IEC, IEEE, or ASME - some of the symbols are such
poor caricatures of standard symbols that they will actually make a schematic difficult to read.
This is because there is not only a mixing between IEC, IEEE, ASME ec.
but with different ages of this librarys, too.
??What I would like to see in the future is a standards-compliant symbol set for KiCAD.??This can start with an IEC60617 directory
with libraries classified according to form or function - that alone will give us many of the symbols we typically use - and then
people can contribute other symbols but those symbols will need to be vetted before they're put into the library tree; once you head
down the path of standardization you really can't afford any compromise - any symbols which have not been vetted will have to go into
a 'non-standard' directory branch.
Ok.
??This is all somewhat academic at the moment.??KiCAD is certainly usable as it is and although it would be great to start
implementing improvements, KiCAD also happens to be in a state of development where it's probably best to hold back on making those improvements.
The actual version of my EN60617 Library is RefE4. So send me your
suggestions for improvement.
With best regards: Bernd Wiebus alias dl1eic
Thanks Bernd,? for now I can't really comment since I don't have a copy of the specifications or a current subscription to the database; my previous comments such as the one about the wire crossing the vertices of the inductor symbol was based on what I remember of specifications ca. 1998.? I think for now, just keeping the standards compliant symbols separate from the others and with perhaps a note in the directory to give the name of the reference document is a good step.? Hopefully in about a year I can put some effort into building and checking symbols.
- Cirilo
