Sorry for answering so late ^^
Why'd you put all components on the "bottom" of the board in Eagle, though? You could have built it all with components on the top as usual, keeping in mind the reversed pinouts of the headers only. Many places charge extra for silkscreening on the "bottom" and you can't just swap bottom for top.
I was originaly going to route a single sided board, so that it can be easily home-etched, but well, that didn't work. I went for the double sided PCB but I forgot to switch the component to the top side. Sorry guys ^^
melka, I hope you don't mind I started with your schematic and did some of my own adjustments.
No problem at all, everything I did is free to use. Well, I didn't do much, but use it as you want ^^
I have a little question : what is the wiggly line inside the board edge ?
Nota bene : I used resistor networks in a QSOP package, but those don't really come cheap.
R220 = 2.35$ : http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=VSSR16-220-JI-ND
R330 = 1.89$ : http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=VSSR16-330-JI-ND
It might be interesting to use 0603 resistors instead, to cut the price down.
In addition, if someone wants to use several boards+display side to side, maybe we should add a row of headers, with the DIM / SCK / SCI / VCC / GND shared with the already existing 6 pins header going to the arduino, and taking the SERIAL OUT of the 4th 74HC595 and wiring it to the SER pin of the "outgoing" header". Not sure if I'm clear here ^^
Nice to see that this board might be useful to someone.