Display layout

While I wait for my USB<->Serial chip to come in I've been working on the display board layout.  Initially I just wired it up and tossed the components on there as I went, and it came out kinda OK I guess

Five 10-LED arrays with resistors and three shift registers to drive them.
The horizontal resistors would have been soldered on the back of the PCB.

But then I remembered that I want the display on the front panel of a 1/3rack 1U enclosure and that (optimistically) gives me 1.35" of vertical space to work with.  Couple this limitation with the 4" width limitation on the free version of Eagle and I simply ran out of room.

My solution (for now at least) is to stack two boards, giving me a poor-man's 4-layer board.  This is very similar to the 'shields' you see available for various pre-made arduino boards.   I separated the bits into display and logic and connected them via headers;  they'll just press together.

In this iteration, all resistors live on the back of the display board, right next to their LED.

The display board has some very, very close traces.  I don't know if this is printable.  I think I'll be using sparkfun's batchpcb.com for this, and possibly for the whole project.   Since they have a (very reasonable) $10 setup fee per board, I may try and have these made as a single board, and just dremmel them apart myself.

In other news, it's finally raining.