Bipe:
Has anyone tried the DFRobot Beetle? I picked one up for a thermal detonator I'm working on. At half the size of the Nano, it might work great in a lightsaber. It uses an atmega32u4, instead of the atmega328p.Links:
https://www.dfrobot.com/product-1075.html
Beetle_SKU_DFR0282-DFRobot
That looks like a good one to try. So small!