Mail Archives: geda-help/2017/08/28/07:53:45
Graham:
> How does one deal with the symbol for a component that has more physical
> pins than symbol pins, because internally some are strapped together? I
> have searched through the Wiki help for some time, looking for a clear
> example, but not yet seen how to do it.
> Some power semiconductors use extra pins, as do many relays.
example:
http://aspodata.se/git/openhw/share/gschem/mechanical1.sym
http://aspodata.se/git/openhw/share/pcb/_mechanical/fibox_tempo_TA191209T_4p.fp
The sym has one pin with pinnumber=1.
The fp has four pins with number parameter eq. 1.
The pcb pin def.:
Pin [rX rY Thickness Clearance Mask Drill "Name" "Number" SFlags]
All pins/pads in pcb with the same "Number" will be treated as one and
the same thing.
> An example is a simple changeover switch relay where there are 8 pins
> altogether.
> Two of the pins can be for the coil, and given a slotdef=1. That part is
> easy.
>
> The remaining 6 pins, using slotdef=2, are arranged such that each internal
> element uses up 2 pins, strapped together internally.
I haven't seen slots used like that, isn't slots for components that
have multiple _identical_ parts, like a four op.amp. chip ?
In your case you only have one thing consisting of two _different_
parts in the package. Since you already have two sym's, just remove
the slotdef attribute and you'll be fine.
> This is where I need to understand how, (or whether) a single gschem symbol
> pin can be actually served by more than one pin in the footprint, and know
> how to arrange pinseq. I have spent some time adding the attributes to the
> example, though I suspect my arrangement might be done better
>
> The example I include does work, but it would be nice to simplify the
> symbol to have only 3 connections, while the associated footprint has 6
> pins connected as 3 pairs.
Remove the redundant pins in the sym and let the internally connected
pins have the same "number" parameter.
Regards,
/Karl Hammar
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