Halogen to LED conversion
Replacing a 50 watt Halogen lamp with ~6 watts of LEDs and a small fan. More images here.
Li-Ion Battery +5 volt supply
A simple boost-mode converter supplying up to 1 Amp at 5 volts from a CR123A cell with battery level readout and low-voltage shutdown. More images + download schematics and code here.
Color Kinetics Fixture DMX Driver
A simple circuit to take a DMX stream and translate the signal levels to drive the original Color Kinetics iColor Cover RGB Fixtures. More images and schematic here.
Esquire 75th Anniversary Cover Hack
My entry in Esquire's E-ink cover hacking challenge. More info here.