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 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
Like was done to inertial AK8963 and inertial sensor move the decision
regarding the I2C bus to the caller. We don't allow changing the address
because apparently HMC5843 doesn't support different addresses.
Changing only the bus could be more easily done but this prepares the
ground for using HMC5843 on an AuxiliarBus.
The need for a more generic abstraction is evidenced by this commit: a
"SerialBus" in AP_HAL would be a nice addition rather than letting each
driver to provide its own. However the methods are a little bit
different from what we have in AK8963. It's safer to do the simple
conversion now and later on to add the abstraction changing everybody to
use it.
Just like was done for inertial sensor, different detect() functions
might need different arguments and passing a pointer to function here is
cumbersome. For example, it forces to have a method like "detect_i2c2"
rather than allowing hal.i2c2 to be passed as parameter.
This commit changes the way libraries headers are included in source files:
- If the header is in the same directory the source belongs to, so the
notation '#include ""' is used with the path relative to the directory
containing the source.
- If the header is outside the directory containing the source, then we use
the notation '#include <>' with the path relative to libraries folder.
Some of the advantages of such approach:
- Only one search path for libraries headers.
- OSs like Windows may have a better lookup time.
Uses reimplemented AK8963 driver. There's also no need trying to detect this
compass twice. Actually, it might even be bad, because the current code can
allocate an AK8963 object twice.
