ardupilot/libraries/AP_Airspeed/AP_Airspeed_PX4.cpp
Andrew Tridgell 291369db7f AP_Airspeed: split up airspeed driver
this gives us separate backends for PX4, analog and I2C. This allows
the MS airspeed sensor to work on Linux, and it should work on APM2 as well.
2013-09-28 21:24:03 +10:00

83 lines
2.2 KiB
C++

/// -*- 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
#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()
{
_fd = open(AIRSPEED_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_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)
{
return _temperature;
}
#endif // CONFIG_HAL_BOARD