Mail Archives: geda-user/2014/07/22/22:24:51
So if anyone has any other footprints that appear to be nasty cases, I
would like to add them to my collection. One of the things DJ's example
did is convince me that "exposure off" (erasure) is a necessary part of
modeling footprints entirely in aperture macros. Additive drawing of
RS-274X primitives is insufficient in the general case.
-dave
On 07/22/2014 10:27 AM, Dave Curtis wrote:
> On 07/22/2014 08:50 AM, DJ Delorie wrote:
>> http://www.bourns.com/data/global/pdfs/SRR6038.pdf
>>
>
> Start with this example of a round-cornered rectangle, copy/pasted from
> the RS-274X spec:
>
> %AMRECTROUNDCORNERS*
> 0 Rectangle with rounded corners. *
> 0 Offsets $4 and $5 are interpreted as the *
> 0 offset of the flash origin from the pad center. *
> 0 First create horizontal rectangle. *
> 21,1,$1,$2-$3-$3,0-$4,0-$5,0*
> 90
> Copyright Ucamco NV.
> 0 From now on, use width and height half-sizes. *
> $9=$1/2*
> $8=$2/2*
> 0 Add top and bottom rectangles. *
> 22,1,$1-$3-$3,$3,0-$9+$3-$4,$8-$3-$5,0*
> 22,1,$1-$3-$3,$3,0-$9+$3-$4,0-$8-$5,0*
> 0 Add circles at the corners. *
> 1,1,$3+$3,0-$4+$9-$3,0-$5+$8-$3*
> 1,1,$3+$3,0-$4-$9+$3,0-$5+$8-$3*
> 1,1,$3+$3,0-$4-$9+$3,0-$5-$8+$3*
> 1,1,$3+$3,0-$4+$9-$3,0-$5-$8+$3*%
>
> Then add a primitive circle with exposure "off" to erase the circle, and
> another primitive rectangle with exposure "off" to erase the rest of the
> gap. Done. That flashes the whole footprint in one go.
>
> Or, you could create a macro for just one of the pads by doing a base
> rectangle, a filler rectangle at the top, two circles for the round
> corners, and one circle with exposure "off". Then use that pad twice to
> create the part footprint. Overall, this would be a simpler macro.
>
>
>
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