I have just purchased the BNO055 sensor and am looking to use it with an Arduino board as an IMU sensor. I am specifically interested in obtaining Euler angle outputs. I am currently using the sample code, "rawdata", in Arduino IDE to obtain Euler angle measurements but am a bit unclear on what coordinate axes the outputted Euler angles are relative to. Is it the coordinate axes of the sensor each time it is powered on, or an absolute coordinate axes? Based on my own testing, it seems to be a combination of these, but it's possible that I'm somehow not using the sensor in the way that it's intended to be used. For example, no matter what Yaw angle I put the sensor in before powering it on, the sensor seems to initialize its starting Yaw angle as 0. This was not true, however, for the Roll and Pitch angles, as their initial values changed based on what the orientation of the sensor was when it was powered on.
