At the Knobcon 2016 synthesizer convention, Scott Rise of Division 6 gave out his business card, above, which is a PCB for making a DIY step sequencer.
The business cards/boards for the little sequencer, which can also be used as a tiny keyboard, were handed out to everybody who attended Knobcon 2016.
Here’s an example of the business card sequencer in action:
Pricing and Availability
Division 6 has a parts kit at their site for US $25 and a kit with the board and parts for $35, along with info for DIY’ers.