I’m trying to draw an Eagle device for the spring terminal strips Sparkfun has ([PRT-08075 for example). For each terminal, they have two pins. How do I make a Device in Eagle that has one pin on the schematic connected to two pads on the package? Anyone have a clue?
Thanks,
Keith](http://www.sparkfun.com/commerce/product_info.php?products_id=8075)
khearn:
I’m trying to draw an Eagle device for the spring terminal strips Sparkfun has. For each terminal, they have two pins. How do I make a Device in Eagle that has one pin on the schematic connected to two pads on the package? Anyone have a clue?
Greetings Keith,
That’s exactly what I did. I’ve made at least two
components that have more physical connections
than electrical ones.
For example, I use a [screw terminal strip(in various
lengths) that has two PCB pins for each circuit, and I
wanted both to be routed in an EAGLE layout.
In another example I have a [PCB mounted fuse clip
that has two PCB pins that in turn are connected to
one net.
Here’s an [example EAGLE schematic.
Comments Welcome!
http://www.stonard.com/SFE/EAGLE/Fuse_t … ropped.jpg[/img]](http://www.stonard.com/SFE/EAGLE/Fuse_terminal_example.sch)](http://www.stonard.com/SFE/EAGLE/fuse.lbr)](http://www.stonard.com/SFE/EAGLE/con-OST-500.lbr)
Bigglez,
That would require me to tie the two pads together on the board, though (or else just accept having an airwire left around and the resulting DRC errors). That can make things more difficult if I need to route a trace between them. It would be nice if there was a way to make Eagle understand that they are connected inside the component instead of just making a second pin and having to connect them together externally. I’ve seen a number of components with this sort of a double-pin issue.
Keith
Greetings Keith,khearn:
That would require me to tie the two pads together on the board, though (or else just accept having an airwire left around and the resulting DRC errors).
Doing that is certainly your option, but your work
will be harder to maintain or share due to bending
the rules. I don’t go to the board editor until the
project passes ERC, and I don’t go to CAM until the
project passes DRC. Leftover airwires are sloppy.
It’s your call.
khearn:
That can make things more difficult if I need to route a trace between them. It would be nice if there was a way to make Eagle understand that they are connected inside the component instead of just making a second pin and having to connect them together externally. I’ve seen a number of components with this sort of a double-pin issue.
I can’t imagine why anyone would route a trace
between the mechanical pins under a connector.
(Routing between rows is common practice, terminals
and fuseholder clips have two pins per contact for
mechanical rigidity).
Using parts with IC (Internal Connections) is also
risky, what if you use a second source supplier which
doesn’t have the same internal link?
I’m often amazed by some production PCB design
work when the products have been in the market
for a while and the PCBs are discoloured or cracked
due to sloppy design and stress.
Like many things in life, there’s “good” and then
there’s “just okay” in PCB design.
Comments Welcome!
khearn:
That would require me to tie the two pads together on the board, though (or else just accept having an airwire left around and the resulting DRC errors).
You can make pins with the same name, like VSS@1, VSS@2, etc (look at any 80 pin PIC device for example). If you don’t want an airwire just leave this pin unconnected on the schematic. Besides, in my copy of Eagle, airwires don’t produce DRC errors.
Someone posted a different solution a while back:
