bcard

About

bcard is an experimental attempt to make cheap electronic business card on a thin PCB. The main goals are for it to be:

• cheap
• not gaudy
• not stupid

My design incorporates a capacitive touch sensor with some blue LEDs around the corners. The blue LEDs are actually mounted upside-down so that the card fluoresces.

Cost of parts is about $1.80 in quantities of 25 (at Digi-Key prices). At quantities of 100, the cost per board is $1.54. The majority of the cost is in the 4 LEDs and the microcontroller. You can shave off a few cents by going with an ATTiny4 instead of an ATTiny10.

IDK, it's cute.

Important Stuff

• Github Repository — Repository on Github (boards layouts, firmware, etc.)
• Introduction — Thought process, etc.
• First Etch — A surprisingly good DIY board etch!
• Assembly Failure — A surprisingly bad mechanical design!
• 2nd Prototype — A working card ready to be programmed
• Third Design — Purely surface-mount design
• Explanation of Capacitive Touch Sensing — Details about how I perform touch sensing with my design