We use a single 9-axis MEMS motion sensor to sense both orientation of the wing and the angle of the line with respect to the wing. Accelerometer and Gyroscope are used to determine the wing orientation. The magnetometer measures the magnetic field of a small magnet attached to a triangle whose vertices are attached to the wing via parallel strings. In the middle of the triangle we attach the kite line. The length of the connecting strings must be such that the magnetic field is greater than any surrounding ones but always smaller than the bounds of the sensor. Furthermore we choose the string lengths such that when the triangle touches the wing the magnetic field measured by the sensor is about 90°. Also the triangle must be as thin as possible to achieve a possible angle near 90° before the triangle tilts and the connecting strings fail to stay parallel.