My initial tests of HoG* have revealed an unexpected surprise; the MPU-9250 is not back compatibly with the MPU-6050 / MPU-9150 as far as registers are concerned. I should have read the specs beforehand!
Don’t get me wrong, it’s working in the briefest of tests, but there has been a radical change in temperature scale (now configurable), dlpf (settable separately for gyro and accelerometer), sampling frequencies (way up to 8kHz!), plus new registers to do really useful things like storing calibration data so the IMU can do the work. And that’s only from the briefest of scans from the spec.
So BYOAQ-BAT articles have stalled again until I’ve found all these changes and added a new class to the code for the MPU-9250, and probably a generic IMU wrapper the uses the common WHO_AM_I register to determine which MPU class code should be used.
To make matters worse, my kids have used all the printer paper in the house for drawing on. I need printouts of these data sheets to stand a chance to find the changes. Off to buy some printer paper tomorrow!
*HoG = Heart of Gold – the superclone of Phoebe, Chloë and Zoë upon which the BYOAQ-BAT articles are based.