ardupilot/libraries/AP_Notify/ToneAlarm_PX4.h

/*
  ToneAlarm PX4 driver
*/
/*
   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/>.
 */
#pragma once

#include "NotifyDevice.h"

// wait 2 seconds before assuming a tone is done and continuing the continuous tone
#define AP_NOTIFY_PX4_MAX_TONE_LENGTH_MS 2000

class ToneAlarm_PX4: public NotifyDevice
{
public:
    /// init - initialised the tone alarm
    bool init(void);

    /// update - updates led according to timed_updated.  Should be called at 50Hz
    void update();

    // handle a PLAY_TUNE message
    void handle_play_tune(mavlink_message_t *msg);
    
private:
    /// play_tune - play one of the pre-defined tunes
    void play_tone(const uint8_t tone_index);

    // play_string - play tone specified by the provided string of notes
    void play_string(const char *str);

    // stop_cont_tone - stop playing the currently playing continuous tone
    void stop_cont_tone();

    // check_cont_tone - check if we should begin playing a continuous tone
    void check_cont_tone();

    int _tonealarm_fd;      // file descriptor for the tone alarm

    /// tonealarm_type - bitmask of states we track
    struct tonealarm_type {
        uint8_t armed                 : 1;    // 0 = disarmed, 1 = armed
        uint8_t failsafe_battery      : 1;    // 1 if battery failsafe
        uint8_t parachute_release     : 1;    // 1 if parachute is being released
        uint8_t pre_arm_check         : 1;    // 0 = failing checks, 1 = passed
        uint8_t failsafe_radio        : 1;    // 1 if radio failsafe
        uint8_t vehicle_lost          : 1;    // 1 if lost copter tone requested
        uint8_t compass_cal_running   : 1;    // 1 if compass calibration is running
        uint8_t waiting_for_throw     : 1;    // 1 if waiting for copter throw launch
    } flags;

    int8_t _cont_tone_playing;
    int8_t _tone_playing;
    uint32_t _tone_beginning_ms;

    struct Tone {
        const char *str;
        const uint8_t continuous : 1;
    };

    const static Tone _tones[];
};