This method will be used to initialize and configure I2C backends that
have an auxiliary I2C bus that can be connected to the main I2C bus,
like MPU6000 and MPU9250.
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.
This is the same change as done in PX4:
This reduces self-heating of the sensor which reduces the amount
of altitude change when warming up. Apparently some individual
sensors are severely affected by this.
Unfortunately it raises the noise level, but Paul is confident
it won't be a significant issue.
This is a new method which will return true if an RC_Channel has a PWM
value that is at its TRIM value plus or minus the allowed dead zone
around the TRIM.
Add a macro to annotate functions that act like scanf. Calling the
printf format macro as FORMAT was bad as can be seen now. Later we need
to rename it to FMT_PRINTF.
This include some minor changes on all methods of PWM_Sysfs:
- Sort headers
- Add code inside Linux namespace rather than just use the namespace
- Declare a union pwm_params, that's only used to calculate at compile
time the maximum stack space we need in our methods: this is a bit
safer for future extensions
- Standardize error messages to include the useful params first and
then the error message
- Remove log message from hot path
- Don't abuse macros for checking error - convert the SNPRINTF_CHECK
macro into proper code, ignoring errors for not enough space since
they can't happen
- Fix call to read_file() passing uint8_t for "%u" in get_period()
- Fix passing char** instead of char* to write_file() in set_polarity()
- Use strncmp() instead of strncasecmp() since the kernel API uses
lowercase.
- Add comments on the 2 main methods of this class
Down-sample the IMU and output observer state data to 100Hz for storage in the buffer.
This reduces storage requirements for Copter by 75% or 6KB
It does not affect memory required by plane which already uses short buffers due to its 50Hz execution rate.
This means that the EKF filter operations operate at a maximum rate of 100Hz.
The output observer continues to operate at 400Hz and coning and sculling corrections are applied during the down-sampling so there is no loss of accuracy.
We are currently not using LowPassFilter2p<double> and it just generates
a lot of warnings on PX4 while instantiating it due to implicitly
promoting float to double:
libraries/Filter/LowPassFilter2p.cpp: In instantiation of
'T DigitalBiquadFilter<T>::apply(const T&, const DigitalBiquadFilter<T>::biquad_params&) [with T = double]':
libraries/Filter/LowPassFilter2p.cpp:86:41: required from 'T LowPassFilter2p<T>::apply(const T&) [with T = double]'
libraries/Filter/LowPassFilter2p.cpp:98:16: required from here
libraries/Filter/LowPassFilter2p.cpp:20:82: warning: implicit conversion from 'float' to 'double' to match other
operand of binary expression [-Wdouble-promotion]
T delay_element_0 = sample - _delay_element_1 * params.a1 - _delay_element_2 * params.a2;
^
Large magnetometer innovations on the ground could be caused by factors that will disappear when flying, eg:
a) Bad initial gyro bias
b) External magnetic field disturbances (adjacent metal structures, placement of hatches with magnets, etc)
To avoid unnecessary switches, we inhibit switching until off-ground and when sufficient time has lapsed from power on to learn gyro bias offsets.
If the magnetometer fails innovation consistency checks for too long (currently 10 sec), then the next available sensor approved for yaw measurement will be used.
The original design intent was to require all axes to pass because severe errors are rarely constrained to a single axis.
This was not achieved with the previous implementation.
These changes move the innovation consistency checks for all three axes to the top before any axes are fused.
Unnecessary performance timers have been removed.
This was problematic to implement with magnetometer switching. It is likely that slow magnetometer learning can still be performed externally (eg plane) but this will need to be monitored to see if it causes issues.
José Roberto de Souza
Lucas De Marchi
Andrew Tridgell
Grant Morphett
Paul Riseborough
Siddharth Bharat Purohit
Jonathan Challinger
lvale