Arduino Magnetometer Student Guide
An example of what your homemade Arduino magnetometer might look like after following the instructions in this guide.
NASA HEAT/Dr. Sten Odenwald
Explains how to build a more advanced homemade magnetometer using a sensor attached to an Arduino microcontroller and computer readout, all of which can be obtained for less than $50. Also provides instruction on how to use the device to take magnetic measurements in the classroom and at home.