kicad-lib-committers team mailing list archive

[Lorenzo Marcantonio <l.marcantonio@xxxxxxxxxxxx>]

On Fri, May 09, 2014 at 06:29:14PM +0200, Kerusey Karyu wrote:
> Some pin graphics must be reviewed/recoded to keep 0.100" or 0.150" pin
> length for black-boxed symbols (That's why I don't use these graphics
> options).

The round negation symbol size seems about proportioned for a 50mil text size;
the polarity symbol instead is too long (they should be big the same, the
triangle should be an "half-square"). The problem it that they don't
scale with the text... i.e. the negation symbol is always about 70mils,
the clock symbol always 40mils, the polarity one about 80mils (didn't
look in the source, I estimated them from the grid). All of these
symbols should be embeddable in a square and high as the text (i.e.
50mils, typically), 60617-12 has quite clear drawings of that.

I too don't use them, mostly because of the semantic difference between
negation and polarity (twisted and confusing topic); I just use the
~SIGNAL method, in case.

I can do the patching required if you want. There exist also less used
symbols to be attached, but I think we can survive without (mostly
the direction arrows). And, by the way, the falling edge clock symbol
simply doesn't exist in 617 (at least until 1997, maybe it was amended
for DDR).

As for the length, just use 150 or 200 mils for pin length, if you need
to use these symbols. While we are in topic the internal spacing (called
"skew", don't know why) should be at least 60 mils for a text size of 50
mils (50 mils for the clock symbol + 5 mils of pen size + another pen
size mandated for legibility).

-- 
Lorenzo Marcantonio
Logos Srl