YMFC-AL - Build your own self-leveling Arduino quadcopter - with schematic and code

The YMFC-AL is an auto-leveling Arduino Uno based quadcopter that is easy to build and fun to fly. Auto leveling means that, when you release the sticks the quadcopter levels itself. This makes it much easier to fly. The YMFC-AL is not a high level flight controller. The purpose of the YMFC-AL is to provide a simple and understandable code that is needed to build an Arduino based auto-level quadcopter flight controller. Website: IMU part 1: