updated on 24-05-2012
Adding this sensor to the existing 6 DOFs of the UDB4 IMU, we obtain a 9 DOFs IMU increasing even more the long term precision. The compass may have big errors for each measures, due to the surrounding magnetic fields (iron, magnets, electromagnetics), but the average value is good enough and constant during the time. Opposed to the long term drift of the gyro, it contributes to enhance the characteristics of the unit.

3 Axis Magnetometer


There are just few things to say about this device. It returns on I2C bus the values for the X, Y, Z magnetic field vectors. Integrating this values with an accelerometers, in order to measure the tilt, we have a tilt compensated compass, that measures the correct north bearing even if the rover is skewed.
The schematic diagram is very simple, everything is inside the chip. Being highly integrated, the datasheet

is not simple as well.


This sensors combination is the electronic equivalent of the nautical compasses, widely used once, where gimbals compensate the tilt of the ship on maintaining the compass in a horizontal asset.