its essential to perform Magnetometer and Accelerometer Calibration for synerduino shield , to ensure stable operation of your vehicle. this can be perform on the FlywiiGUI Flight Deck Tab labeled Calibrate ACC & Calibrate Mag respectively.
Calibrate ACC – place the Vehicle on a flat surface and hold it there 5-10 seconds.
Calibrate MAG – rotate the Vehicle 360 in all axis for 60 Seconds
Magnetic Declination – or magnetic variation, is the angle on the horizontal plane between magnetic north (the direction the north end of a magnetized compass needle points, corresponding to the direction of the Earth’s magnetic field lines) and true north . this is important that your Vehicle is orientated correctly to its true north by this. compare your vehicle compass with an external compass lets say your phone,s compass to see of your settings are correct.