Much has happened since the last update. I have received a panel, as well as the balance of the components that I ordered. The panel has a half-inch scratch on the front, so hopefully it is still functional.
The design has been steadily progressing. The architecture of the board is now a bit more complex – a Freescale Kinetis-L2 (ARM Cortex-M0+) processor is onboard, primarily because it was cheaper than the competing TI MSP430 that I had planned on using, go figure. To accompany this, a Mini-USB header has been added. This will not power the system as per other folks’ designs because I refuse to violate the USB spec (and my motherboard) that badly, but it will allow for connectivity to the host in order to (hopefully) enable control of the panel from keyboard hotkeys. A Linear Technology LT3502 switching regulator has been added to provide 3.3V for the panel and the processor, and a Skyworks AAT4618 high-side switch was put in place to allow power to the panel to be disabled when the system is inactive for greater power efficiency. The board should operate from something like 8 to 40V DC, for whatever power adapter you happen to have around that fits.
So there it is. The board is now fully routed and has been sent out for manufacture. Naturally this means I’ve started noticing errors in it, but I’ve not found anything that means it altogether won’t work. Getting matched trace lengths on the mDP lines took a couple hours, and was probably the one most time consuming part of the design, but now all 8 lines are matched to within 10 mils. This is probably excessively close, but what the hell – as long as we’re doing it, may as well do it right. The final dimensions of the board ended up at 2.525 by 1.5 inches – quite a bit smaller than I originally planned on. And it is dense. We’ll see how well everything works.
(2013-05-07) I will not be releasing documents for this board for a while as I have noted a serious flaw in the processor section. I will use these for debugging the power system then respin the board when I am satisfied.