I was excited that there was a kit for this. However there appears to be a flaw in it. The magnetometer sensors are for ± 50uG. That is not large enough. There are areas in the world including the northern part of the US that the natural magnetic field exceeds that. See this URL.
http://www.geomag.bgs.ac.uk/education/earthmag.html
Also some of the software to load the programs is only for windows machines.
More info about the sensors would be helpful. (fluxgate, mu metal etc)
We just resell their (FGSensors) design. For more info click on 'documents; tab for the:
Sensor
https://www.fgsensors.com/_files/ugd/70 … a69add.pdf
https://www.fgsensors.com/_files/ugd/70 … 3e4a0d.pdf
https://www.fgsensors.com/_files/ugd/70 … cf6841.pdf
Kit
https://cdn.sparkfun.com/assets/1/f/b/8 … er_Kit.pdf
It does have seem to have a usable range (but you’d have to calibrate its linearity to your locale!)
Their website & blog also has more use-cases and more info https://www.fgsensors.com/blog