Dual Led Matrix Shield design advice

So I decided to learn how to use Eagle, and I wanted to design a pcb for 2 dual rg led matrices, 6 shift registers, and 2 sink drivers.

I then decided I wanted to have it printed, but I don't have the supplies to do so myself, so I am using batchPCB.

This is probably a big thing to ask, but would it be possible for someone to look over my schematic and board before I order it?

Here's the board:

Here's the schematic:

Schematic: Could the wiring be looked over?
Board: The board is the same as the schematic. So, wiring is not important to be checked. But how about stuff like dimensions?

I'm a noob to this, so any advice would be appreciated!

Well, after learning a bunch more about eagle, I made a bunch of changes to the board. I will upload the board file soon. Do you guys have any file hosting websites you'd reccommend?
Nothing changed electronically, so I still am wondering If anyone could look over the schematic.
Thanks

Here's the new board:

Tell me if you have advice regarding technical things like placement of parts, or advice on things like board shape and silkscreens.
I'm a noob to Eagle, so i wouldn't be surprised if I made some stupid error!
:slight_smile:

You may get some advice if you post the image of the board rather than a link to an Eagle file.

Here's the board:
'http://img339.imageshack.us/img339/4729/ledmatrixbig.png

And the schematic:
The pic was pretty big so I decided not to put it here.
http://img94.imageshack.us/img94/7427/ledmatrixschem.png

I recommend you use decoupling capacitors (100nF), one for each 595.
Also, did you try to power your LEDs with a 330 ohms resistor? You should have about 1.7V on a red or green LED.

I have tried using a 330 ohm resistor, and it was fine.
How would a 0.1 uF capacitor work, and where should I connect it?

and where should I connect it

I think from Power to Ground as close to the supply going to the chip as possible. I believe this filters out noise.

How would a 0.1 uF capacitor work, and where should I connect it?

If you don't have enough room on the top face of the board, you can always solder them on the bottom face, between GND and Vcc pins of each 595.
Where there is switching there are spikes. Decoupling capacitors cut the spikes.
(Keep that in mind if your microcontroller gets reset from time to time.)

Okay so I'll do that.
Any other advice before I get ready to order this?

Are the traces big enough for the power youmay have running through them? :slight_smile:

I dunno. That's sorta the kind of advice I was looking for.
Do you think they are wide enough?

Your power and ground traces should be at least 25 mil. That, along with the .1uF caps will make sure your power is clean.

Okay thanks.
One question: can I set individual traces in eagle to be certain widths? If so, how? Because I'll probably screw something up of I randomly try things. :smiley:

You set the line width on the tool bar when routing. I always route the power and ground traces by hand, then change the trace width to 10 or 8 mil. You can then run the auto-router or continue to hand route.

Okay, so I didn't actually reroute the whole thing, I just made the power traces wider.
The power traces are now 25 mil, and the other traces are 10 mil.
I will be soldering the caps to the bottom of the board, rather than actually build them into the board.
So, the only differences from the picture I posted are the trace widths and a couple extra moves to avoid collisions.
Does this look ready to order from batchPCB?
If so, could someone explain what I do with regard to exporting, etc?

I'm not sure how you output the files from Eagle. I use DipTrace. All I know is that you must output for a Gerber RS-274-X device. I'm sure there are forum posts regarding this issue. Just do a search. :wink:

I just ordered the board! Yay! Hopefully it will work mostly!
By the way, if I find I put an incorrect trace, how can I remove it or break it on the board?