I might as well retitle my blog "The Art of the Blink Sketch", but this one has a bit of a twist:
The Quarantatre is a breakout board for the ATtiny43U microcontroller (basically just an implementation of the reference design shown in the AVR188 application note, though I did not follow the component layout recommendations all that closely).
In addition to the typical features found in other ATtiny models, the ATtiny43U has a built in boost converter allowing it to not only run off a single AA or AAA battery, but even to generate a regulated 3V voltage. While this only allows for a small current draw (apparently the limit is around 30mA), this could potentially be interesting for some applications.
The boost converter needs a few external components to work, and some of them, especially the Schottky diode, are not really available in breadboard friendly variants, so to truly test the boost converter, I had to make this custom PCB (available for ordering at OSH Park, design files on Github).
As usual, I've made an Arduino-style core available on Github at https://github.com/microtherion/arduino-tiny1634-43u (migrating from Google Code, which is shutting down). The standard Arduino tool chain probably won't support it; as always, I recommend CrossPack-AVR for OS X.