The JC pro Macro acts as a rotary input and auxiliary macro keyboard for your PC, powered by an Arduino Pro Micro.

Each keyswitch is fed into a Pro Micro input, and set as an input pullup, avoiding the need for resistors, or diodes. A rotary encoder is also fed into the Pro Micro, adding rotational input as well a sixth button input when pushed down. I2C pins, as well as +5V and GND are broken out, allowing for additional functionality, like the small OLED screen shown below.

By default it's now set up for media control, and to cycle through browser tabs. It can also move the mouse randomly when needed to keep the computer awake. The Pro Micro board can also be reprogrammed for different functionality as needed.

The build is outlined in the video below. The board was first designed in KiCad, then exported to Fusion 360 for mechanical design. Programming is via the Arduino IDE. Code and more information is found via the linked GitHub repository.

If you'd like to build one yourself, the PCB will be available on my Tindie store, and I plan to set up more purchase options for associated materials in the near future.