PCB Business Card: It Works!
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.
Reader Comments (2)
Cool. Which fab house are you using for the PCBs?
@Adrian
Gold Phoenix in China. They do a pretty good job, and are very fast.