Wearable gadgets,such as smartwatches and smart glasses, typically use various kinds of motion sensors,such as accelerometers,gyroscopes,and magnetometers.The magnetometer utilized in these wearable devices is characterized by its low magnetic hysteresis effect,compactness,and low power consumption.The angular sensor applied to the rotating bezel and crown side of the smartwatch detects the rotation angle on both sides to implement the multifunctional window switching feature.Augmented Reality and Virtual Reality (AR & VR) are innovative applications that require the magnetometer to calibrate the accumulated inaccuracy from the gyroscope.