31 March 2018
PCB Business Card
A first attempt at making a PCB business card, built as a tiny magic 8 ball. Slide in a CR2032 battery, ask it a question, shake the card, and one of eight LEDs gives you the answer.
What It Does
The circuit uses a CD4017 decade counter, eight LEDs, resistors, and a tilt sensor. The battery sits between three PCB fingers inspired by Brian McGarry's three-finger battery holder design.
When the card is shaken, the tilt sensor advances the counter. When it settles, whichever LED remains lit becomes the answer.
Parts Used
- Custom PCB business card
- CD4017 decade counter
- 8 red LEDs
- 10k and 220 ohm resistors
- SW-200D tilt sensor
- CR2032 coin cell battery
Process
- Design the simple LED counter circuit.
- Lay out the PCB in Eagle.
- Send the board files for manufacture.
- Solder the parts, test the tilt action, and tweak the next version.
Cost Notes
The parts were sourced as cheaply as possible, mostly from AliExpress, with the boards printed by PCBWay. The rough total was EUR14.45 for ten cards, or about EUR1.45 each.
Photos
