Working with the magnetometer
A magnetometer reads magnetic field strengths in 3D to produce a vector. Code you write can use this to find the magnetic north, in the same way as a compass. In this section, we'll look closer at the device, learn how to get a reading from it, and see what vectors it produces.
It may be useful to have a space with very few magnets present. Let's understand the magnetometer more.
Understanding the magnetometer
A compass measures a heading from the Earth's magnetic field by using a magnetized needle or disk. The following image is of a compass:

Figure 12.19 – A traditional compass
The compass shown in the preceding image has a rotating magnetized disk balanced on a center pin. This variety is a small button compass, which is about 25 mm in diameter.
Our chosen IMU contains a device known as a magnetometer. This electronically senses a magnetic field and can be used as a compass.
Most magnetometers...