FXOS8700 Breakout giving strange O/P Moderators: adafruit_support_bill, adafruit

[MJAChapman]

I have purchased some FXOS8700 9DOF breakout boards and cannot get them to work properly. It seems that the magnetic sensors are giving inconsistent results on the 2 samples I have tried. I have used the recommended sketches (ahs_fusion_usb) on an M0 platform selecting both the Mahoney and Madgwick filters testing on a horizontal base. When rotating the hardware through 360deg the heading gives inconsistent heading (yaw) results against a traditional compass. The readings from the magnet sensors seems low and asymmetric, i.e. the values are not the same when the plane is rotated through 180deg. I was expecting the magnetic sensor value to be +ve in one direction and the -ve [b]magnetic sensor value [/b ]in the opposite direction (ignoring a small offset). Note: the pitch and roll seems to be consistent.

The attached text file shows the configuration and the readings from the sensors in each plane. Note: some of the reading do not match the orientations shown in the datasheet!