- no longer start sercon or mavlink usb by default
- on USB connection (VBUS) monitor serial USB at low rate and start Mavlink if there's a HEARTBEAT or nshterm on 3 consecutive carriage returns
- the mavlink USB instance is automatically stopped and serdis executed if USB is disconnected
- skipping Mavlink USB (and sercon) saves a considerable amount of memory on older boards
- simple state machine to reset, configure, etc
- checked register mechanism (sensor will reset itself on configuration error)
- configured in 16 bit mode (1320 LSB/Gauss instead of 330 LSB/Gauss)
- adjusted orientation handling in driver to match datasheet as closely as possible
- in many external compass units the rotation was wrong and very difficult to actual determine how to set correctly
- accel & gyro FIFOs enabled
- FIFO watermark on data ready interrupt
- sensor side filtering completely disabled
- gyro now respects `IMU_GYRO_RATEMAX` (up to 2 kHz)
- saves a few % cpu (at default rate)
Removes the calibration on startup, as these values were overwritten by
the system calibration values anyway.
So the only difference is that if all calibration scales were equal to 1,
the driver startup would have failed.
- it does nothing useful
- increases boot time by 2 seconds on pixhawk 4 due to a poll timeout:
IST8310 on I2C bus 3 at 0x0e (bus: 100 KHz, max: 400 KHz)
WARN [ist8310] ERROR: TIMEOUT 2