rpi_rc_in.h

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#pragma once

/*! @file rpi_rc_in.h
 * Raspberry Pi driver to publish RC input from shared memory.
 * It requires the ppmdecode program (https://github.com/crossa/raspberry-pi-ppm-rc-in)
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdint.h>
#include <unistd.h>

#include <px4_platform_common/px4_config.h>
#include <px4_platform_common/px4_work_queue/ScheduledWorkItem.hpp>
#include <px4_platform_common/defines.h>

#include <drivers/drv_hrt.h>

#include <uORB/uORB.h>
#include <uORB/topics/input_rc.h>

#define RCINPUT_MEASURE_INTERVAL_US 20000

namespace rpi_rc_in
{
class RcInput : public px4::ScheduledWorkItem
{
public:
    RcInput() : ScheduledWorkItem(MODULE_NAME, px4::wq_configurations::hp_default) {}

    ~RcInput();

    /** @return 0 on success, -errno on failure */
    int start();

    /** @return 0 on success, -errno on failure */
    void stop();

    bool is_running()
    {
        return _is_running;
    }

private:
    void Run() override;
    void _measure();

    int rpi_rc_init();

    bool _should_exit = false;
    bool _is_running = false;
    orb_advert_t _rcinput_pub = nullptr;
    int _channels = 8; //D8R-II plus
    struct input_rc_s _data = {};

    int *_mem = nullptr;
    key_t _key = 4096; ///< shared memory key (matches the ppmdecode program's key)
    int _shmid = 0;
};

static void usage(const char *reason);
static RcInput *rc_input = nullptr;
}
extern "C" __EXPORT int rpi_rc_in_main(int argc, char **argv);