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/**
* @file mc_land_detector_main.cpp
* Land detection algorithm for multicopters
*
* @author Johan Jansen <jnsn.johan@gmail.com>
*/
#include <unistd.h> //usleep
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <drivers/drv_hrt.h>
#include <systemlib/systemlib.h> //Scheduler
#include <systemlib/err.h> //print to console
#include "MulticopterLandDetector.h"
//Function prototypes
static int mc_land_detector_start();
static void mc_land_detector_stop();
/**
* land detector app start / stop handling function
* This makes the land detector module accessible from the nuttx shell
* @ingroup apps
*/
extern "C" __EXPORT int mc_land_detector_main(int argc, char *argv[]);
//Private variables
static MulticopterLandDetector* mc_land_detector_task = nullptr;
static int _landDetectorTaskID = -1;
/**
* Deamon thread function
**/
static void mc_land_detector_deamon_thread(int argc, char *argv[])
{
mc_land_detector_task->landDetectorLoop();
}
/**
* Stop the task, force killing it if it doesn't stop by itself
**/
static void mc_land_detector_stop()
{
if(mc_land_detector_task == nullptr || _landDetectorTaskID == -1) {
errx(1, "not running");
return;
}
mc_land_detector_task->shutdown();
//Wait for task to die
int i = 0;
do {
/* wait 20ms */
usleep(20000);
/* if we have given up, kill it */
if (++i > 50) {
task_delete(_landDetectorTaskID);
break;
}
} while (mc_land_detector_task->isRunning());
delete mc_land_detector_task;
mc_land_detector_task = nullptr;
_landDetectorTaskID = -1;
warn("mc_land_detector has been stopped");
}
/**
* Start new task, fails if it is already running. Returns OK if successful
**/
static int mc_land_detector_start()
{
if(mc_land_detector_task != nullptr || _landDetectorTaskID != -1) {
errx(1, "already running");
return -1;
}
//Allocate memory
mc_land_detector_task = new MulticopterLandDetector();
if (mc_land_detector_task == nullptr) {
errx(1, "alloc failed");
return -1;
}
//Start new thread task
_landDetectorTaskID = task_spawn_cmd("mc_land_detector",
SCHED_DEFAULT,
SCHED_PRIORITY_DEFAULT,
1024,
(main_t)&mc_land_detector_deamon_thread,
nullptr);
if (_landDetectorTaskID < 0) {
errx(1, "task start failed: %d", -errno);
return -1;
}
/* avoid memory fragmentation by not exiting start handler until the task has fully started */
const uint32_t timeout = hrt_absolute_time() + 5000000; //5 second timeout
while (!mc_land_detector_task->isRunning()) {
usleep(50000);
printf(".");
fflush(stdout);
if(hrt_absolute_time() > timeout) {
err(1, "start failed - timeout");
mc_land_detector_stop();
exit(1);
}
}
printf("\n");
exit(0);
return 0;
}
/**
* Main entry point for this module
**/
int mc_land_detector_main(int argc, char *argv[])
{
if (argc < 1) {
warnx("usage: mc_land_detector {start|stop|status}");
exit(0);
}
if (!strcmp(argv[1], "start")) {
mc_land_detector_start();
}
if (!strcmp(argv[1], "stop")) {
mc_land_detector_stop();
exit(0);
}
if (!strcmp(argv[1], "status")) {
if (mc_land_detector_task) {
if(mc_land_detector_task->isRunning()) {
warnx("running");
}
else {
errx(1, "exists, but not running");
}
exit(0);
} else {
errx(1, "not running");
}
}
warn("usage: mc_land_detector {start|stop|status}");
return 1;
}