My PCB business card works now. Check it out. Please see my previous posts for more information, and leave a comment if you need help modifying the Eagle CAD files to make your own.
If you haven’t read any of my previous posts, I’d like it to be clear that I borrowed heavily from Mike Puchol’s layout and ideas.
I was very wary of the Propeller Chip’s ability to run of a coil-cell, since it’s rated at 3.3 V. I asked about the feasibility of doing so on the Parallax forums, but didn’t get much information. I guess someone needs to do the testing. My design uses a CR2032 coin-cell. As an aside, that means 20 mm x 3.2 mm. They’re rated at 3V, but I find it’s more like 2.9 due to the relatively high internal resistance of these cells. They really aren’t meant to supply more than a trickle of current, in the µA region. In this design, I coded the LED’s so only one is lit at a time, and they sink about 2 mA @ 2.9 when on. I’d be surprised if the circuit could still run if I removed the decoupling capacitors.
The code is very ugly and hard-coded at this point, but I will provide it anyway.
Download the DigiKey bill of materials.
Download the Eagle CAD files.
Download the Spin code.