"The Shrediquette is a tri-rotor helicopter built by William Thielike from Germany. William is a PhD student in biology, who seems to have many talents: micro-controller system design, control, mechanical design, flying contraption construction, as well as film making.
His tricopter is built around an Arduino Pro Mini micro-controller. Oddly, William didn't use the Arduino development tool and C/C++ programming language: he wrote his software in Bascom, a dialect of BASIC.
The yaw control is performed by rotating the tail boom with a servo. This very unlike the more conventional servo-less yaw control of quadcopters, but it's practically unavoidable for tricopters.
Much of the material is available for download, including the schematics, the PC board Eagle files, and the Bascom source code."