Motion sensors are responsible for measuring acceleration forces and rotational forces acting along three axes of the phone. Motion sensors include the accelerometer, the gyroscope, gravity, linear acceleration, signification motion, the step detector, and the step counter. The detailed list of motion sensors can be found in Chapter 1, Sensor Fundamentals. In the next section, we will be discussing these sensors individually in detail. We will cover the step detector and step counter in the next chapter.
The accelerometer sensor determines the acceleration along the x, y, and z axes, which is applied to a phone by measuring the forces acting on the phone. The measured acceleration includes both the physical acceleration (change of velocity) and the static gravity acting on the phone all the time. Accelerometer sensors are made up of the Micro Electro Mechanical System (MEMS), which is an embedded system that integrates electronic...