- new IMU driver structure with state machine (no sleeps in bus thread)
- verify all configured registers and trigger reset on failure
- detect if DIO1 or DIO2 are actually connected for data ready interrupt usage
- don't use CRC-16 on burst transfers except for verified lots
- currently the main change is that it reduces the max number of ORB multi instances to 4, but usage will be expanded as needed
- limits number of EKF2 multi instances to 2.
- enabled on all cortex m4 boards
- checked register mechanism and simple watchdog
- driver checks for errors gradually and can reconfigure itself
- respect IMU_GYRO_RATEMAX at the driver level
- fixed sensor INT16_MIN and INT16_MAX handling (y & z axis are flipped before publishing)
- increased sensor_gyro_fifo max size (enables running the driver much slower, but still transferring all raw data)
- PX4Accelerometer/PX4Gyroscope remove unnecessary memsets
Daniel Agar
David Sidrane
Tanja Baumann
SalimTerryLi