555 Timer Business Cards by Cody Shaw via HaD.

So I thought up this cool little project during my last few weeks during my co-op term at Echologics Engineering. I saw everyone had nice, professional looking business cards, and I needed something to springboard myself into PCB design and manufacture. One and one came together, and this idea came about.

There were quite a few idea revisions in my mind before I actually got around to spinning the PCB. Microcontroller? Basic LED’s? No circuitry at all? Finally I got the idea of using a 555 timer (after seeing something about worldwide 555 timer competitions on the EEVBlog) that would be outputting a clock to LED’s, which would flash depending on some external interaction to the timer.