Does the DI IMU inertial measurement unit come with one of the sensor mounts shown in five of the seven photos on the IMU purchase page?
I’ll double check but I don’t think so.
ETA: Confirmed, the sensor is not included.
Thanks; I didn’t think so, but worth a double check.
Continuing in this “IMU Mounting” stream of thought, the DI examples that use the IMU appear to be consistent with the orientation, although I have difficulty understanding the reference directions.
Q: I’m guessing the DI suggested mounting gives: y positive up, x positive right when viewed from rear, z positive toward front (right-hand-rule consistent)?
This whole subject of coordinate references haunts me. The default DI Servo interface uses 0 degrees left and 90 degrees forward, while the IMU using -atan2(-X, Z) or arc tangent of X over Z seems to put 0 degrees forward and 90 degrees to the right, if I am following the code correctly.
(If anyone is following this thread and wondering if this matches ROS, the answer is no. ROS uses X forward, Y right, Z up following “the right-hand-rule”. I’m not venturing into the ROS world until I reach a Raspberry Pi computation limit.)
The CompassBot shows front mounting, and the easy_inertial_measurement.py interface suggests “on GPG3 we ask that the IMU be at the back of the robot, facing outward.”
Q: Is there a GoPiGo3 mounting location which yields the best measurements?