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.
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.
read() calls accumulate() which takes the lock by itself so we must
release it like we were doing before 669ae26 ("AP_Compass: encapsulated
calibration in HMC").
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.
_copy_to_frontend function takes care of abstracting
this code from the driver. For now the function takes
care of the offset and rotation that is common.
the first couple of values after we enter strap mode may be low, but
just above our 0.7 threshold. We now discard the first two values to
prevent these affecting the average.
Also added some commented out debug code and a comment on the scaling
of the calibration code
- Define float versions of math functions to the double versions
on AVR (eg. #define sinf sin).
- These macros appear to be missing in older versions of avr-libs.
- Include AP_Math.h rather than math.h to get these definitions.
- Allows use of hardware floating point on the Cortex-M4.
- Added "f" suffix to floating point literals.
- Call floating point versions of stdlib math functions.
