After finally running out of my last batch of paper business cards I decided to change things up on the next round. I’ve seen a handful of PCB business cards over the years and thought it would be fun try it out for myself. The PCB is standard business card size at 3.5 x 2 inches, but much thicker at a maximum of 3mm for the USB port. The text is tin plated copper achieved by placing it on the soldermask resist layer. The final cards will feature black soldermask and ENIG plating. The card has a SAMD11D14 ARM processor, AP2112 LDO supplying 3v, and USB Micro port for communication.
The microcontroller is loaded with the Arduino bootloader and comes programmed with a simple version of Tetris playable over a serial COM port. When plugged in the card enumerates as a serial device running at 9600 baud, and plays a simple tetris game. Code for the business card is based on ArduinoTermTetris by Johannes le Roux available here: https://github.com/dadecoza/ArduinoTermTetris The board also includes breakouts for most of the SAMD11D14 GPIO, as well as pads for a 32khz crystal for the onboard RTC.
I’m working on several different versions with various sensors and firmwares to extend the business cards functionality. All board files and firmware are published on my github: https://github.com/slapplebags/business-card