Over at SpriteMods, [sprite_tm] realized that a microcontroller could be used as a boost converter to power itself. A boost converter steps up voltage from a battery by switching the output of a coil.

The MT3608 is a popular boost converter, able to easily step up DC voltages in useful ranges, at an incredibly low cost. Modules can be sourced from eBay for less than $2, built on a PCB ...

The Texas Instruments LM2733XMF/NOPB stands out as a high-efficiency boost converter developed to meet the requirements of various power management applications. Available now from WIN SOURCE, the ...