SparkFun Forums

[clang]

Hi all,
I am really new to all this and need help by you.
I need a PCB to mount/solder the Wii-IR Cam on to get the data via I2C to my Arduino. Apparently there don't exist any PCB to purchase, at least not a 3.3V version which I would prefer to use with my Arduino FIO.
After a lot of googling I found the spec of the pins of the IR-camera and some example PCBs (5V) and learned that I would need to use a 25MHz oscillator crystal to get it to work. At this point I decided to try to design my custom WII-IR-CAM PCB as a 3.3V version on my own.
Currently I am just happy that I passed the DRM-Check at BatchPCB.
I know that there may be missing some pullup/down resistors and decoupling condensators, too. The placement of the components and routing could also get a review.
Could anyone please help me to complete this design?

Attached you'll find a ZIP-File containing my *.brd and *.sch file and also the crystal library I am using.
http://www.mediafire.com/?d4zu8icbateudvu

Kind regards,
Christian

PS:
I didn't find my fist try to post this topic, hopefully this is not a double post. If it's actually a double-post feel free to delete this.

[clang]

Well, don't know if there was anything wrong regarding my questions, but I suppose I asked for too much.
I'd like to give my topic another try before vanishing on page two of "PCB Design Questions".
Assuming that I connected all the nets right, what would be the next logical step to get a "good" PCB?
Adding decoupling caps? Adding Pull-Up/Down resistors? Or am I missing something else?

Kind regards,
Christian

[n1ist]

To have the best chance of people reviewing things, post them here in pdf form. Many people won't jump thru hoops to review a board.

I have never used the Wii camera, but here are a few notes:

Schematic:
- Make a custom schematic symbol for the camera. It's confusing going from the text notes about camera pin numbers to the schematic showing two 4-pin connectors.
- Add a 100n decoupling cap for the oscillator
- Add pullups for SDA and SCL, unless you will count on having them on some other device on the i2c bus. I would add them anyway as you can always leave the parts off
- The reset pin needs a 22-30k pullup and a 100n cap to ground. In your schematic, the camera is always held in reset
- QG1 is a crystal oscillator, not a crystal resonator
- In general. positive power symbols point up and ground and negative symbols point down.

PCB:
- Check the footprint of the camera; is the row-to-row spacing 100 mils or 150 mils?
- You have text on pads, text off the board, and text on vias. These should be cleaned up
- Vias usually are round - they take less space that way and that gives more options of how to hit them with a trace. Square thru-hole pads are usually only used for pin-1 indicators
- Traces should connect to pads and traces at right or obtuse angles. Acute angles can trap acid during etching
- Move the pin-1 designator for QG1 off the pad. Ideally, it should be outside the footprint so it is visible after the part is loaded
- If you plan to hand-solder the board, I would extend the pads for QG1 a bit (10-15 mils) to give you a chance of hitting them with the iron
- You have no mounting holes
- If you have the space, add the board name, revision, and date on the silkscreen. Bottom silk is fine.

/mike

[clang]

Thank you.
I will "rework" my board based on your hints.
When I get stuck, I will ask again and make a copy of the board in pdf form.
Maybe this board will get some more attention, when it's done.
I believe there are a lot of useful and cool things to achieve with the IR-Cam (although one has to break a Wii-Mote for getting the cam).