For all supported boards the maximum number of instances is 3. The
number of HIL_COMPASSES was already defined as 2 instead of 3, so this
is left as before.
We don't support HAL_CPU_CLASS <= HAL_CPU_CLASS_16 anymore. This makes
COMPASS_MAX_INSTANCES and COMPASS_MAX_BACKEND constant for all supported
boards.
Instead of requiring every program to specify the HAL related modules,
let the build system do it (in practice everything we compiled depended
on HAL anyway). This allow including only the necessary files in the
compilation.
The switching between different AP_HAL was happening by giving different
definitions of AP_HAL_BOARD_DRIVER, and the programs would use it to
instantiate.
A program or library code would have to explicitly include (and depend)
on the concrete implementation of the HAL, even when using it only via
interface.
The proposed change move this dependency to be link time. There is a
AP_HAL::get_HAL() function that is used by the client code. Each
implementation of HAL provides its own definition of this function,
returning the appropriate concrete instance.
Since this replaces the job of AP_HAL_BOARD_DRIVER, the definition was
removed.
The static variables for PX4 and VRBRAIN were named differently to avoid
shadowing the extern symbol 'hal'.
offset parameter units are milligauss
User settable parameters should have a User category defined. Those that should never be set by a user should not have this.
The function rotate_field() can change the values axes and the function
correct_field() applies offsets (which are already in milligauss). Thus any
sensitivity adjustment must be done for two reasons:
(1) The offsets must be applied to the values already in milligauss;
(2) The factory sensitivity adjustment values are per axis, if any rotation
that switches axes is applied, that'll mess with the adjustment.
Experiments showed that before this patch the length of the mag field reported
quite different from the expected. After this patch, the same experiments
showed reasonable values.
This is part of the transition to make all mag field values be used in
milligauss. Additionally the value of _gain_multiple is adapted to the new way
we're using it and corrected accordingly to the datasheets.
The use of _gain_multiple is not necessary because the values of
expected_{x,yz} and _mag_{x,y,z} are both in sensor raw unit (i.e., lsbs).
That wasn't fixed before in order not to make APM users to recalibrate their
compasses.
the previous approach assumed a 1:1 mapping between compass backends
and compass instances, which isn't true on PX4.
It also only setup milligauss offsets on a set_and_save call, which is
not the only way offsets change
this adds a milligauss_ratio per instance, which is considerably
simpler
AK8963 is configured in 16-bit ADC mode which implies sensitivity of 0.15 uT/LSb. Knowing this fact we can convert the measurements to the proper units. The change will make users recalibrate their compasses.
From now on there's a pair get_field_milligauss() and
get_offsets_milligauss() that can make the transition to the common
units across all compasses easier.
Gustavo Jose de Sousa
Andrew Tridgell
Lucas De Marchi
Caio Marcelo de Oliveira Filho
Jonathan Challinger
José Roberto de Souza
Randy Mackay
mirkix
mirkix
raspilot
Julien BERAUD
Staroselskii Georgii
Siddharth Bharat Purohit