There are a few inevitable truths in this world. Taxes will rise, Wookies shed all over the furniture, Luke and Leia are related, and there is no such thing as a perfect first draft schematic.
The Rev2 circuit is nearly complete. It looks AMAZING if I do say so myself. That’s the problem, though: I’m inundated with excitement and therefore am unable to find things that are wrong because I don’t want to find any reason that might delay getting the circuit boards back as soon as possible.
I’m calling out for a few extra set of eyes to look over the schematic If anyone could please go to the Google code, download the Eagle CAD files and take a look, I’d really appreciate it. If you want to make changes, let me know so I can arrange for them to be merged back in properly. Even if you’ve never looked at schematics before, take a look and as always, feel free to ask what’s going on in the comments.
This is also a great chance to give suggestions on functionality. I should add, it may be your LAST chance! Please give some comments if you think you might ever build one, if nothing else just to say you think it works for what you’d like to use it for.
If you’re not familiar with CAD schematics and circuit board layouts, it might be interesting to look at the history of the .sch and .brd files in the Google Code repository. By looking at older revisions, you can see the steps taken along the way chronologically. I commit changes at least at the end of almost every day I work on the project.
The current Bill of Materials can also be found at this Google Docs spreadsheet. It includes estimated pricing – it currently comes in at just under $200. A little bit higher than I was hoping, but about the same cost as Rev1 and Chuck Norris (adverbicized) packed with new extra features!
The schematic is hopefully organized well enough for someone not intimately familiar with this project to try and understand one section of the schematic at a time. The capacitive touch schematic is separate, because it will be a separate board. The way it works is you put copper pads on the board, glue it to the inside of your enclosure, and it senses you touching it on the outside of the enclosure. Pretty nifty, and a great way to avoid milling the enclosure.
Please post comments below, or add to the Google Groups discussion page.
So, the stats tools on WordPress are kind of impressive … and useful at correcting idoits like me. I’ve talked all around it, but I noticed I haven’t released an actual bill of materials and noticed quite a few people have been searching for it. Maybe they want to build a ZephyrEye? I’ll try to do my best to appease the masses. It’s been quite a while since I actually built the hardware, but here it goes…
Lucky for me, and anyone else using EagleCAD, there’s a handy User Language Program (ULP) called bom.ulp that autogenerates a BOM. It only lists items that are actually on the schematic, however, so don’t forget things: the LCD connector denotes you should also buy an LCD display. I’ve never made that mistake though.
Partlist exported from /home/brad/Development/zephyreye/trunk/cad/ZephyrEye Rev0.2.sch at 2/11/10 1:32 PM
|8||TAC_SWITCHPTH||SW_DOWN, SW_IN, SW_LEFT, SW_OK, SW_ONOFF, SW_OUT, SW_RIGHT, SW_UP|
|7||.1uF||C-USC0603K||C3, C7, C17, C18, C21, C22, C23|
|3||1uF||CAP_POL1206||C8, C9, C12|
|2||2.2uF (TANT)||C-USC0603K||C14, C15|
|4||10uF||CAP_POL1206||C1, C2, C6, C10|
|3||470||R-US_R0603||R6, R8, R16|
Most of the “primary” components are from Sparkfun, with most of the passives, voltage regulators, etc. coming from Digikey. So, on top of this list, you’ll also need:
- Case: Pac-Tec PP Enclosure
- 1/16″ Acrylic, available from local hobby shop
- LCD connector
- EM408 GPS module connector
- 2mm headers for the XBee
- An extra 500mA rated LDO regulator for the GPS.
If anybody is seriously interested in making one of these guys, let me know. If at least 10 people are interested, I would be willing to make kits at cost (should be ~10-20% cheaper), and help those wary of the SMT soldering (for a nominal reimbursement). Keep in mind the programming either comes from you, me, or the community and that the software has basic functionality but is not yet complete. Also, you’ll want at least two (unless you want to use it for something other than paintball/laser tag gaming).
Note: I’ve started adding a few product links in. As I have time, I’ll fill in the rest. Feel free to help out in the comments if you find links to products (from SparkFun or DigiKey generally) before I do.