This repository contains an open hardware business card running open source software.
A blogged a detailed write up of this project. You may also want to check out the corresponding Hackaday.io project.
Using KiCad, add Silkscreen details such as your name. E.g. I added my contact details and word cloud of my skills on the back of the PCB. Using the JLCPCB fabrication plugin of KiCAD, you can export the production files to directly order the PCBs.
Note that when using vanilla PCB options (1.6 mm PCB thickness, HASL surface finish) the USB connector will be a tad too thin to perfectly make contact with a USB socket. Ideally you would use 2.0 mm PCB thickness and ENIG surface finish, but that would be so expensive that it defeats the purpose of a business card. Instead, you can just add a bit of solder on the USB contacts to increase the thickness.
A simple "hello world" demo is given in
software/RIOT-based-apps/apps/hello-world that you can flash using e.g. a
J-Link EDU Mini programmer. Rather than using a cable, just plug the pins of
the J-Link EDU Mini programmer from the underside through the holes and rotate
the programmer until the pins and holes have contact. In addition, you need to
power the board (ideally via a USB-A extension cord).
With the programmer connected and the board powered, simply run:
make flash
The "default" application will be software/RIOT-based-apps/apps/games, as
this contains a game launcher that allows running all currently added games.
Refer to the RIOT documentation for more details on the software.