I've been playing more. I don't notice an effect on the compass (rc_test_dmp -m -c) until the IMU is within about 2cm of one of the motors (not running). I'm sure that different motors have different magnetic fields. I haven't even begun to explore with the motors running. I don't know all the potential factors but I can say with confidence that the motors I got are el cheapo.
Using rc_test_imu I see that the raw IMU magnetic field readings away from the motors are all in the 10-60µT range. Within about 15-20cm away from these motors I see definite changes in the tens of µT range, within about 8cm I see readings over 100 µT, and within about 1cm I've seen over 2000µT. This isn't at all rigorous, I'm just waving a BBBL in the air while watching the output of rc_test_imu to get an intuitive sense of the strength and shape of the magnetic field around the motors. It's a little more work to see what it's like when the motors are running, since running one of these rc_* test programs kills the others, so I can't run rc_test_motors while running rc_test_imu; to do the equivalent with running motors, I'll have to combine the test programs. ☹ On Sunday, May 14, 2017 at 4:14:49 PM UTC-4, Clark Sann wrote: > > Thanks for that. I'm hoping I don't have any ill effects if I locate a BB > Blue 6" or so away from motors. This is on a 48" radio controlled boat so I > can probably put it further away if I need to. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/4fdc7428-270b-4645-8559-118767f5a177%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
