Towards fast I/O in Arduino for AVRs 
WWVB clock progress 
Chris was kind enough to pass along to me a commercial WWVB receiver. This module was a bit of a pain to develop for, because most of the time the interference from a nearby laptop computer is enough to seriously compromise reception, and almost all of the time having a USB cable running from the microcontroller to the laptop will kill reception outright.
Towards my GPS LED Light Clock 
A few years ago, I made a CCFL light clock using an Arduino with a custom shield containing a transformer (to get a reliable 60Hz timebase) and a triac (for solid-state switching of the lamp). By having a simple 7-day alarm calendar (set at compile time), the clock seldom requires interaction except for the reading lamp function. However, the design has two main problems:
Arduino Random Number Generator 
… rate possible in a 16MHz AVR -> FTDI design and 10 bits per byte is the…
… Uno which use a second avr to implement the USB interface; I suspect that it does…
at90usb162 single-sided board 
I got an e-mail request for this board. You may use this eagle (4.x) library, schematic, and board under the GNU GPL version 2 or later, or CC-BY-SA.
Autoreprogram for DFU devices 
… name your .hex file (and avr partnumber if it's different), then leave it running in the…
at90usb162 gotcha: PC0 vs XTAL2 
Improved Analog & Digital Interface with Arduino 
… weak pull-up built into the AVR microcontroller. For the analog inputs and outputs, the default gain/scale…