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/****************************************************************************
*
* Copyright (c) 2013-2015 PX4 Development Team. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name PX4 nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/**
* @file LandDetector.cpp
* Land detection algorithm
*
* @author Johan Jansen <jnsn.johan@gmail.com>
* @author Morten Lysgaard <morten@lysgaard.no>
*/
#include "LandDetector.h"
#include <unistd.h> //usleep
#include <drivers/drv_hrt.h>
LandDetector::LandDetector() :
_landDetectedPub(-1),
_landDetected({0, false}),
_taskShouldExit(false),
_taskIsRunning(false)
{
//ctor
}
LandDetector::~LandDetector()
{
_taskShouldExit = true;
close(_landDetectedPub);
}
void LandDetector::shutdown()
{
_taskShouldExit = true;
}
void LandDetector::start()
{
//Make sure this method has not already been called by another thread
if (isRunning()) {
return;
}
//Advertise the first land detected uORB
_landDetected.timestamp = hrt_absolute_time();
_landDetected.landed = false;
_landDetectedPub = orb_advertise(ORB_ID(vehicle_land_detected), &_landDetected);
//Initialize land detection algorithm
initialize();
//Task is now running, keep doing so until shutdown() has been called
_taskIsRunning = true;
_taskShouldExit = false;
while (isRunning()) {
bool landDetected = update();
//Publish if land detection state has changed
if (_landDetected.landed != landDetected) {
_landDetected.timestamp = hrt_absolute_time();
_landDetected.landed = landDetected;
/* publish the land detected broadcast */
orb_publish(ORB_ID(vehicle_land_detected), _landDetectedPub, &_landDetected);
}
//Limit loop rate
usleep(1000000 / LAND_DETECTOR_UPDATE_RATE);
}
_taskIsRunning = false;
_exit(0);
}
bool LandDetector::orb_update(const struct orb_metadata *meta, int handle, void *buffer)
{
bool newData = false;
//Check if there is new data to grab
if (orb_check(handle, &newData) != OK) {
return false;
}
if (!newData) {
return false;
}
if (orb_copy(meta, handle, buffer) != OK) {
return false;
}
return true;
}
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