this allows enable/disable of fast sampling per IMU, making
experimentation easier.
It also fixes the fast sampling to always average over 8 samples, and
fixes the 9250 to use the correct accumulator when not doing fast
sampling
This allows each sensor to be uniquely identified in the system by using
either the index inside the backend or for those that use the Device
interface, to use the bus type, location, and device id.
We leave 16-bit for each sensor to be able to change its own
identification in future, which allows them to be changed in an
incompatible manner forcing a re-calibration.
We only leave the parameter there for backward-compatibility. However
product id on the inertial sensor is not much useful since it's only
kept for the first instance.
A better implementation per-gyro and per-accel is needed in order to
avoid problems with sensors taking the offsets configured for another
sensor.
We should return the number of bytes written/read, not 0 on success.
This number may be useful in some cases so return it.
While at it fix a simple wrong space in the header.
Using MPU9250 over I2C we can connect the auxiliary bus where there is
a AK8963 and connect this bus to the main one, this way we don't need
any AuxiliaryBus infrastructure as we need with SPI and we can talk
with AK8963 as we would talk with a standalone AK8963.
The PSTR is already define as a NOP for all supported platforms. It's
only needed for AVR so here we remove all the uses throughout the
codebase.
This was automated with a simple python script so it also converts
places which spans to multiple lines, removing the matching parentheses.
AVR-specific places were not changed.
In order to avoid confusion between sample rate from sensor and sample rate
from the frontend class (AP_InertialSensor), use "raw sample rate" to refer to
the former.
The changes in the code were basically done with the following commands:
git grep -wl _accel_sample_rates | xargs sed -i "s,\<_accel_sample_rates\>,_accel_raw_sample_rates,g"
git grep -wl _set_accel_sample_rate | xargs sed -i "s,\<_set_accel_sample_rate\>,_set_accel_raw_sample_rate,g"
git grep -wl _accel_sample_rate | xargs sed -i "s,\<_accel_sample_rate\>,_accel_raw_sample_rate,g"
git grep -wl _gyro_sample_rates | xargs sed -i "s,\<_gyro_sample_rates\>,_gyro_raw_sample_rates,g"
git grep -wl _set_gyro_sample_rate | xargs sed -i "s,\<_set_gyro_sample_rate\>,_set_gyro_raw_sample_rate,g"
git grep -wl _gyro_sample_rate | xargs sed -i "s,\<_gyro_sample_rate\>,_gyro_raw_sample_rate,g"
And also with minor changes on indentation and comments.
