Instead of depending on the frequency accumulate() is called, use
AverageIntegralFilter with 10 samples. The data obtained by BMP085 is
too noisy with any value of OVERSAMPLING so use twice the number of
samples as currently used. Besides that now we are sure there's always
10 samples used in the average.
The temperature readings is not subject to white noise so there's no
point in averaging its reading. Moreover since for a normal 50Hz
accumulate() / 10Hz update() it would read temperature only once per
update(), it's pointless to keep averaging and introducing rounding
error.
The temperature doesn't need to be checked as frequent as pressure, too.
The datasheet even suggests on section 3.3, page 10 to enable standard
mode and read the temperature at 1Hz. Here we reduce it to 2Hz
(considering the accumulate() function being called at 50Hz).
If we don't have EOC pin and assuming the accumulate() function is
called at 50Hz (or higher) we would take very few samples to accumulate
before the update is called. That's because since we have to wait 26ms
to get a sample and we calling accumulate() every 20ms, half of the
times it will return without getting anything. So we will
be using 2 or 3 samples only to average.
If we don't have EOC, use OVERSAMPLING=2 which gives us more noise, but
that we can filter out by using measurements to average. When we have
EOC we don't need it because most of the time the conversion will take
less than 20ms: I'm getting 16ms on most of them while bench-testing.
We don't need to expose to other libraries how each backend is
implemented. AP_Baro.h is the main header, included by other libraries.
Instead of including each backend in the main header, move them to where
they are needed. Additionally standardize the order and how we include
the headers.
The advantages are:
- Internals of each backend is not exposed outside of the
library
- Faster incremental builds since we don't need to recompile
whoever includes AP_Baro.h because a backend changed
The PSTR is already define as a NOP for all supported platforms. It's
only needed for AVR so here we remove all the uses throughout the
codebase.
This was automated with a simple python script so it also converts
places which spans to multiple lines, removing the matching parentheses.
AVR-specific places were not changed.
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.
this changes the barometer calculations to floating point. On a MS5611
this is actually about twice as fast as the previous 64 bit
calculations, but gains us more accuracy as we are able to take
advantage of sub-bit precision when we average over 8 samples.
this allows the barometer driver to calibrate and return altitude and
climb rate values. This will be used by the AHRS drift correction code
for vertical velocity
The climb rate uses a 5 point average filter
the averaging array was using 16 bit numbers, but we are storing
numbers with 19 significant bits. That caused overflow at high
altitude, and some very interesting altitude graphs!
Thanks to Michael Oborne for spotting this in a log
* Wire.begin removed from AP_Baro_BMP085::init()
* SPI.begin removed from AP_Baro_MS5611::init()
* SPI.begin removed from AP_InertialSensor_MPU6000::hardware_init()
* Both Wire.begin and SPI.begin added very early in init_ardupilot in
ArduCopter/system.pde and ArduPlane/system.pde
Lucas De Marchi
Caio Marcelo de Oliveira Filho
Gustavo Jose de Sousa
Andrew Tridgell
Andrew Tridgell
Randy Mackay
Mike McCauley
Janne Mäntyharju
Pat Hickey
uncrustify
Jason Short