Badger 2040 E Ink Keypad

Pimoroni's Badger 2040 is a “stylishly monochrome, maker-friendly, ePaper badge(r),” which is, of course, powered by an RP2040 microcontroller. It has five buttons on the top and a USB-C connector, plus a number of other connections on the bottom. This combination means that it's more than capable of being used as a macro keypad with no modifications. Andreas Känner’s Badger 2040 keypad turns it into just such a device, with the key map displayed in glorious E Ink monochrome.

What’s even more interesting about his setup, is that in addition to working with the onboard buttons (in a custom housing), it can connect into a key switch base module, adding on 12 additional inputs. The Badger module is held on to the base via rare earth disk magnets, and electrical connections between the two parts are completed by a series of pogo pins. Installation is simply a matter of placing the Badger unit in the proper orientation, and the key map display adapts accordingly.

Electrical components are fairly sparse in the base, including an MCP23017 IO expander unit that allows it to transfer signals and power via just four pogo pin connections. Sockets are used for the key switch connections, which are optional, but allow them to be easily swapped out as needed. The system’s code is configured in such a way that it doesn’t matter which expander IO a key switch is wired to, as assignments are specified in the firmware.

It’s quite a slick setup, meaning you no longer have to choose between taking your name tag or a macropad on your next adventure!