ardupilot/libraries/AP_Airspeed/AP_Airspeed_PX4.cpp

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/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
/*
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* PX4 airspeed backend
*/
#include <AP_HAL.h>
#if CONFIG_HAL_BOARD == HAL_BOARD_PX4 || CONFIG_HAL_BOARD == HAL_BOARD_VRBRAIN
#include <AP_Airspeed_PX4.h>
#include <drivers/drv_airspeed.h>
#include <uORB/topics/differential_pressure.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
extern const AP_HAL::HAL& hal;
bool AP_Airspeed_PX4::init()
{
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_fd = open(AIRSPEED0_DEVICE_PATH, O_RDONLY);
if (_fd == -1) {
return false;
}
if (OK != ioctl(_fd, SENSORIOCSPOLLRATE, 100) ||
OK != ioctl(_fd, SENSORIOCSQUEUEDEPTH, 15)) {
hal.console->println("Failed to setup airspeed driver rate and queue");
}
return true;
}
// read the airspeed sensor
bool AP_Airspeed_PX4::get_differential_pressure(float &pressure)
{
if (_fd == -1) {
return false;
}
// read from the PX4 airspeed sensor
float psum = 0;
float tsum = 0;
uint16_t count = 0;
struct differential_pressure_s report;
while (::read(_fd, &report, sizeof(report)) == sizeof(report) &&
report.timestamp != _last_timestamp) {
psum += report.differential_pressure_raw_pa;
tsum += report.temperature;
count++;
_last_timestamp = report.timestamp;
}
if (count == 0) {
return false;
}
pressure = psum / count;
_temperature = tsum / count;
return true;
}
// read the temperature
bool AP_Airspeed_PX4::get_temperature(float &temperature)
{
if (_temperature < -80) {
// almost certainly a bad reading. The ETS driver on PX4
// returns -1000
return false;
}
temperature = _temperature;
return true;
}
#endif // CONFIG_HAL_BOARD