It may not be the most elegant macro keyboard in the world, but it allows wireless (bluetooth) and physical (USB) connection and shows the functions of the keys in a very legible way without consuming battery.

Some components need to be soldered.

I've printed it with a 0.6mm nozzle but I guess any other will do.

The small recess at the bottom of the keyboard is for storage so you don't lose a Bluetooth device in case your computer needs one.

Necessary electronics: 

• Adafruit 2.9" Grayscale eInk
• Adafruit Feather nRF52840 Express
• Battery Lipo 3.7V
• FeatherWing Proto
• Cables
• dip interruptor