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.
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.
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.
In case of error or zeroed data, the i2c semaphore wasn't given.
It happened at first startup on Bebop and caused a failure:
"PANIC: failed to take _bus->sem 100 times in a row..."
No need to repeat the same comments on 3 different places. Instead add a
single comment to explain how start_measurements() and read_raw() are
related.
Don't use a state machine in AK8963: the start_measurements() method
should be called only once. Even if there's a magnetic sensor overflow
the only thing we should do is to discard the new data.
This also moves the _collect_samples() method to be inside _update()
since it's the only place it should be called from, the one running on
the timer thread.
We need to check the AK8963's id before anything else Here we are
reordering the calls to _calibrate() and _check_id(). After that we
don't need to read and write again the AK8963_CNTL1 register.
While at it do some renames as well:
- _configure() -> _setup_mode(): since now there's a
_bus->configure() it became confusing what actually it's
doing.
- make error messages say what we were actually trying to do but
couldn't. Also remove PSTR since this is linux-only.
- start_conversion() -> start_measurements(): We are instructing the
bus to start to get the samples, not to tell the chip to start an
analog->digital conversion like in other sensors.
The MPUREG_PWR_MGMT_1 defines were used when we cared about the MPU9250
initialization code. Now all initialization is done by the MPU9250 class
itself, so remove these defines.
Also remove AK8983_SELFTEST_MAGNETIC_FIELD_ON that is never used and let
the defines always with 2 bytes to improve readability.
Similar code was added in the read_raw() implementation for each bus.
Add a new POD struct read_raw to contain the registers from the AK8963
and use it instead as argument.
José Roberto de Souza
Gustavo Jose de Sousa
mirkix
mirkix
Julien BERAUD
Andrew Tridgell
Staroselskii Georgii
Siddharth Bharat Purohit
Jonathan Challinger
Lucas De Marchi
dgrat
Randy Mackay
Tom Pittenger