In Flygonial's solenoid pusher variant of the Protean, space has been allotted for a Seeed RP2040 microcontroller. This battery door gives the user the option to connect a micro thumbstick and LCD I2C for a simple UI. 

I have not yet figured out code that will utilize these parts, but will update once I do. I am not a coder, so I am very open to people offering up their own. 

The materials needed are the prints themselves, plus a puck-style analog switch (SparkFun Electronics COM-09426) and any 16x2 LCD I2C.

All parts are designed to friction fit into place with some minor adjustments. The thumbstick will need to have the screw tabs clipped off and sanded flush with the body – once that's done, the part will snap into place. It's recommended that a small amount of superglue is used on the edges to keep the thumbstick in place, as downward pressure may cause it pop out. The LCD will need its upper row of pins bent for it to properly seat – be careful not to damage the soldering.

NOTE: this door isn't symmetrical/ambidextrous. It is currently oriented to be held in the right hand. It will need to be mirrored for left-handed use.