Meet RUDY, the ATmega328 Breadboard Development Module
Sven Gregori has designed a simple board that makes it easy to prototype projects using the V-USB library.
As Sven Gregori puts it, “The ATmega328 is just the perfect general-purpose 8-bit microcontroller. It's cheap, it's a great compromise of size and functionality offering enough memory, peripherals, and I/O pins for a wide variety of prototyping projects, and it comes in a breadboard-friendly package.” After all, it forms the heart of the Arduino Uno, which has been used to blink countless LEDs, power small robots, and create all manner of other interesting projects.
As neat as it is for beginners, the Uno and its ilk can be difficult to actually use with a breadboard, requiring a number of jumpers to send and receive the appropriate signals. If you want to use the ATmega328 sans breadboard, that requires a few other components and additional knowledge.
RUDY, which is short for RUDEGAARD, or “Random USB Device Enabling Generic, Arduino-compatible-ish ATmega328 Rapid Development,” straddles the gap between these two use cases. Gregori's small dev board plugs directly into a breadboard, but provides a 12MHz crystal, ISP header, mini USB connector, as well as a voltage regulator to allow it to run on 3.3V or 5V as needed. There are even power indicator LEDs that emits a nice glow underneath.
One neat feature here is that it doesn’t have an external USB chip, but instead uses the V-USB library to take care of this with software. More info can be found on GitHub and its official page here.