Data-ready pin wasn't being used before due to a bug in the Kernel with
concurrent accesses to GPIO in Intel Baytrail platforms. That has been fixed in
Kernel version 4.2.
With commit 24f4153 ("AP_HAL_Linux: RCOutput_PCA9685: group writes") a
log was introduced when we can't get the bus semaphore. However since we
are calling the non blocking method, failing there is not that unlikely
if the bus is shared. Return back to the previous behavior of not
logging.
This removes errors in the in-flight reset of the earth field states by:
1) Using a state vector and magnetometer measurement from the same time coordinate
2) Not using the AHRS trim offsets in the calculation
dtIMUactual has been spit into a separate dtDelAng and dtDelVel and dtDelVel1 and dtDelVel2 delta time in recognition of the amount of timing jitter and different update rates for the IMU's
Vibration in the 400Hz delta angles could cause the angular rate condition check for in-flight magnetic field alignment to fail.
The symptons were failure to start magnetic field learning as expected when EK2_MAG_CAL=3 was set.
The calculation of a delta rotation between consecutive magnetometer samples has been introduced instead of the most recent IMU delta angle as this is less affected by noise and give an upper bound on the angular error.
the check has been moved into the magnetometer fusion control function so that any reset will be performed using fresh magnetometer data
Explicitly set Plane parameters rather than rely on use of the default
If no type defined, default to Copter parameters (most common platform type
Enable different platform types to use different initial accel bias uncertainty
Reduce initial accel bias uncertainty for copter to prevent initial oscillation in bias and height estimate
Large baro data errors when flying without GPS could cause total failure of the EKF.
This patch provides protection against this happening in-flight but allows for large innovations during preflight alignment.
Vibration in the 400Hz delta angles could cause the angular rate condition check for in-flight magnetic field alignment to fail.
The symptons were failure to start magnetic field learning as expected when EK2_MAG_CAL=3 was set.
Use the more robust, but less accurate compass heading fusion up to 5m altitude
Wait for the magnetometer data fusion time offset to be correct before using data to reset states
Don't reset magnetic field states if the vehicle is rotating rapidly as timing offsets will produce large errors
When doing the yaw angle reset, apply the reset increment to all quaternions stored in the output buffer to avoid transients produced by yaw rotations and the 0.25 second fusion time horizon offset.
Only do the one yaw and mag reset at 5m, not two at 1.5 and 5.0m
Always re-do the yaw and mag reset when leaving the ground.
Lucas De Marchi
Gustavo Jose de Sousa
Andrew Tridgell
Paul Riseborough