Trying to get an HMC5883L to compensate for being installed in 90 degrees. Doesn't seem to me that it'll need too complex math or accelerometer. But I have no idea how to do the compensation for it. Any idea?
Using the Adafruit HMC5883L and its library.
You can always use the normal tilt compensation equations with a fixed value instead of a calculation from the accelerometer; Since you know the rotation beforehand the equations may not be as complex. For example, if the tilt is only on one axis, it's just one rotation matrix multiply (and you don't need to calculate the result z axis) instead of 3 in general.
If the tilt is constant and exactly 90 degrees, You just need to swap which magnetometer axis are put into the magnetic field angle equations. If one axis is pointed towards the center of the earth, you can use the other two axis to calculate the direction of the magnetic field without an explicit rotation transformation.
