Have an Adafruit Circuit Playground Express (CPX) project for the Empire? Here's an enclosure for your CPX that any Sith Lord or Emperor would enjoy. It has a snap-fit lid; mounts for threaded inserts to secure your CPX; ports for wires, power and USB; and maybe a small LiPo battery in there too. Openings in the lid give you access to the input and reset button on the CPX.
For you Rebel scum out there, a variant lid for your feeble alliance is available too.
I created this for my make of K2S0's head (https://www.thingiverse.com/make:594475 by 300zxcolin https://www.thingiverse.com/300zxcolin/) where I added LEDs to the eyes, but should work for any project where an outboard microcontroller will do the job.
Update (2/24): enlarged the opening for the micro-USB port to accommodate a wider range of micro-USB cables.
Let me know how you would improve it. More room for wiring? More space for a battery? Modular version is coming up next.
Feel free to try without the supports.