The official YMFC-3D quadcopter project page - Downloads.
Project YMFC-3D
Here you can download the Arduino sketches and the schematic.
The hardware schematic
www.brokking.net/YMFC-3D/YMFC-3D_schematic.jpg
Arduino sketch for testing the receiver signals
www.brokking.net/YMFC-3D/YMFC-3D_receiver.zip
Arduino sketch for testing the gyro outputs
www.brokking.net/YMFC-3D/YMFC-3D_gyro.zip
The gyro search program to detect the gyro and get the correct address
www.brokking.net/YMFC-3D/YMFC-3D_gyro_search.zip
Arduino sketch for testing the esc's outputs
www.brokking.net/YMFC-3D/YMFC-3D_esc_output.zip
The final flight controller sketch
www.brokking.net/YMFC-3D/YMFC-3D_Flight_controller.zip