This is a bread board prototype of a multi-mode pen light. It shines white, red, green, and blue light. Intensity is adjustable. Strobe, emergency flasher, ‘psychedelic,’ and candle simulation functions. It’s powered by a USB phone battery charger pack and uses an ATTiny85 as the microcontroller.
Here it is in action:
Here’s the schematic:
UPDATE: And here’s a sketch of what the completed flashlight might look like: