Hack Notes CVA 090717
North Paw Hack Notes, July 17th, 2009
Sticky Back Velcro
Eric bought $20 worth of sticky back velcro at the Fabric Outlet, and proceeded to cut small pieces for the enclosure, the battery packs, and the stuff necessary for the motor pockets. 30 kits worth took about an hour.
Compass Chip Research
Eric found this interesting paper on Electronic Compass Design using KMZ51 and KMZ52, the KMZ51 is out of stock at digikey, but priced at only 4.67/1, 3.74/25, etc. My brief reading of the stat sheets makes it look like this is a 1-axis compass chip, only available in surface mount. So we'd need to make a little module with two of them and some headers. But I imagine in quantity you could get the cost of said module down under $10.
There are also lots of little "hall effect" magnetic sensors, e.g. Asahi HQ-0111, which could be adapted as above as well. No idea on pricing of these though.
Also, I found the iPhone chip, it's an AKM part, AK8973, available for $6.30, min order 3000. We'd have to build a breakout board, but there is already interest in that at Sparkfun, so it's a potential business idea.
Ordering More Stuff
We ordered the LEDs, some shrink tubing, and some plastic bags (ones which don't seal). Mitch gave us a tip to really cool bags which do seal: Uline poly bags. You have to order 1000 at once, but even so it's not that expensive ($50).
We also discovered (too late for mouser order!)that we forgot to put the 0.1uF caps in the digikey order, but for now we're going to borrow them from NB, to be returned after our next digikey/mouser order.