One of the first articles we did was on the hmc6352 digital compass. Well this is his older brother (or younger but smarter). I really don’t know what to say about the HMC5883L other than it is a three axis magnetometer, so it is capable of sensing in 3 directions.
That doesn’t mean that it is tilt compensated, because you really don’t know how it is orientated when the reading comes in. For that, you would need to combine this with an accelerometer to do that. But this can get you one step closer. If you are looking at using this as a digital compass, make sure to read the following section.
Magnetic Declination
Something I found interesting and obvious once I thought about it, is that all compasses point to magnetic north, and not true north. The difference between them is called Magnetic declination. And how much they vary depends on where you are, and… when it is, because as weird as it is, it changes over time (awesome animation of that). You can look up your Magnetic declination here.
Read more: Triple Axis Magnetometer HMC5883L + Arduino