A Persistence of Vision Business Card

In many professions you’ll give out business card after business card, most of which likely get tossed aside, perhaps to be retrieved as needed one day. If you absolutely want to make an impression, however, you could build a POV device in the same style as James Cochrane’s.

The card, when shaken, displays the word “SMILE,” or whatever else you have in mind, using an ATtiny85 for control, along with a push button and tilt switch. Unlike traditional POV displays where a series of LEDs rotates in the same direction, the business card is instead designed so that when the receiver shakes it, the message is only displayed in one direction. It cuts off when moving in the other direction via the tilt switch, where it would normally show the message backwards and combined with the forward letters to produce gibberish.

Cochrane’s project uses five blue LEDs to reveal the message, and as seen in the video below, Cochrane apparently makes each one using toner etch process. More info, including code and an SVG image that you can modify to suit is available on GitHub, and he’s quick to cite this POV card write-up by ‘sponges’ as a good resource for building this type of device.