text: /****************************************************************************
   *
   *   Copyright (c) 2012-2017 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 mavlink_receiver.cpp
   * MAVLink protocol message receive and dispatch
   *
   * @author Lorenz Meier <lorenz@px4.io>
   * @author Anton Babushkin <anton@px4.io>
   * @author Thomas Gubler <thomas@px4.io>
   */
  
  /* XXX trim includes */
  #include <px4_config.h>
  #include <px4_time.h>
  #include <px4_tasks.h>
  #include <px4_defines.h>
  #include <px4_posix.h>
  #include <unistd.h>
  #include <pthread.h>
  #include <stdio.h>
  #include <math.h>
  #include <stdbool.h>
  #include <fcntl.h>
  #include <string.h>
  #include <drivers/drv_hrt.h>
  #include <drivers/drv_accel.h>
  #include <drivers/drv_gyro.h>
  #include <drivers/drv_mag.h>
  #include <drivers/drv_baro.h>
  #include <drivers/drv_range_finder.h>
  #include <drivers/drv_rc_input.h>
  #include <drivers/drv_tone_alarm.h>
  #include <time.h>
  #include <float.h>
  #include <unistd.h>
  #ifndef __PX4_POSIX
  #include <termios.h>
  #endif
  #include <errno.h>
  #include <stdlib.h>
  #include <poll.h>
  
  #include <mathlib/mathlib.h>
  
  #include <conversion/rotation.h>
  
  #include <systemlib/param/param.h>
  #include <systemlib/systemlib.h>
  #include <systemlib/mavlink_log.h>
  #include <systemlib/err.h>
  #include <systemlib/airspeed.h>
  #include <commander/px4_custom_mode.h>
  #include <geo/geo.h>
  
  #include <uORB/topics/vehicle_command_ack.h>
  
  #include "mavlink_bridge_header.h"
  #include "mavlink_receiver.h"
  #include "mavlink_main.h"
  
  static const float mg2ms2 = CONSTANTS_ONE_G / 1000.0f;
  
  MavlinkReceiver::MavlinkReceiver(Mavlink *parent) :
  	_mavlink(parent),
  	_mission_manager(parent),
  	_parameters_manager(parent),
  	_mavlink_ftp(parent),
  	_mavlink_log_handler(parent),
  	_status{},
  	_hil_local_pos{},
  	_hil_land_detector{},
  	_control_mode{},
  	_global_pos_pub(nullptr),
  	_local_pos_pub(nullptr),
  	_attitude_pub(nullptr),
  	_gps_pub(nullptr),
  	_sensors_pub(nullptr),
  	_gyro_pub(nullptr),
  	_accel_pub(nullptr),
  	_mag_pub(nullptr),
  	_baro_pub(nullptr),
  	_airspeed_pub(nullptr),
  	_battery_pub(nullptr),
  	_cmd_pub(nullptr),
  	_flow_pub(nullptr),
  	_hil_distance_sensor_pub(nullptr),
  	_flow_distance_sensor_pub(nullptr),
  	_distance_sensor_pub(nullptr),
  	_offboard_control_mode_pub(nullptr),
  	_actuator_controls_pub(nullptr),
  	_global_vel_sp_pub(nullptr),
  	_att_sp_pub(nullptr),
  	_rates_sp_pub(nullptr),
  	_force_sp_pub(nullptr),
  	_pos_sp_triplet_pub(nullptr),
  	_att_pos_mocap_pub(nullptr),
  	_vision_position_pub(nullptr),
  	_vision_attitude_pub(nullptr),
  	_telemetry_status_pub(nullptr),
  	_rc_pub(nullptr),
  	_manual_pub(nullptr),
  	_land_detector_pub(nullptr),
  	_time_offset_pub(nullptr),
  	_follow_target_pub(nullptr),
  	_transponder_report_pub(nullptr),
  	_collision_report_pub(nullptr),
  	_control_state_pub(nullptr),
  	_gps_inject_data_pub(nullptr),
  	_command_ack_pub(nullptr),
  	_control_mode_sub(orb_subscribe(ORB_ID(vehicle_control_mode))),
  	_global_ref_timestamp(0),
  	_hil_frames(0),
  	_old_timestamp(0),
  	_hil_local_proj_inited(0),
  	_hil_local_alt0(0.0f),
  	_hil_local_proj_ref{},
  	_offboard_control_mode{},
  	_att_sp{},
  	_rates_sp{},
  	_time_offset_avg_alpha(0.8),
  	_time_offset(0),
  	_orb_class_instance(-1),
  	_mom_switch_pos{},
  	_mom_switch_state(0),
  	_p_bat_emergen_thr(param_find("BAT_EMERGEN_THR")),
  	_p_bat_crit_thr(param_find("BAT_CRIT_THR")),
  	_p_bat_low_thr(param_find("BAT_LOW_THR"))
  {
  }
  
  MavlinkReceiver::~MavlinkReceiver()
  {
  	orb_unsubscribe(_control_mode_sub);
  }
  
  void
  MavlinkReceiver::handle_message(mavlink_message_t *msg)
  {
  	if (!_mavlink->get_config_link_on()) {
  		if (_mavlink->get_mode() == Mavlink::MAVLINK_MODE_CONFIG) {
  			_mavlink->set_config_link_on(true);
  		}
  	}
  
  	switch (msg->msgid) {
  	case MAVLINK_MSG_ID_COMMAND_LONG:
  		if (_mavlink->accepting_commands()) {
  			handle_message_command_long(msg);
  		}
  
  		break;
  
  	case MAVLINK_MSG_ID_COMMAND_INT:
  		if (_mavlink->accepting_commands()) {
  			handle_message_command_int(msg);
  		}
  
  		break;
  
  	case MAVLINK_MSG_ID_OPTICAL_FLOW_RAD:
  		handle_message_optical_flow_rad(msg);
  		break;
  
  	case MAVLINK_MSG_ID_PING:
  		handle_message_ping(msg);
  		break;
  
  	case MAVLINK_MSG_ID_SET_MODE:
  		if (_mavlink->accepting_commands()) {
  			handle_message_set_mode(msg);
  		}
  
  		break;
  
  	case MAVLINK_MSG_ID_ATT_POS_MOCAP:
  		handle_message_att_pos_mocap(msg);
  		break;
  
  	case MAVLINK_MSG_ID_SET_POSITION_TARGET_LOCAL_NED:
  		handle_message_set_position_target_local_ned(msg);
  		break;
  
  	case MAVLINK_MSG_ID_SET_ATTITUDE_TARGET:
  		handle_message_set_attitude_target(msg);
  		break;
  
  	case MAVLINK_MSG_ID_SET_ACTUATOR_CONTROL_TARGET:
  		handle_message_set_actuator_control_target(msg);
  		break;
  
  	case MAVLINK_MSG_ID_VISION_POSITION_ESTIMATE:
  		handle_message_vision_position_estimate(msg);
  		break;
  
  	case MAVLINK_MSG_ID_ATTITUDE_QUATERNION_COV:
  		handle_message_attitude_quaternion_cov(msg);
  		break;
  
  	case MAVLINK_MSG_ID_LOCAL_POSITION_NED_COV:
  		handle_message_local_position_ned_cov(msg);
  		break;
  
  	case MAVLINK_MSG_ID_GPS_GLOBAL_ORIGIN:
  		handle_message_gps_global_origin(msg);
  		break;
  
  	case MAVLINK_MSG_ID_RADIO_STATUS:
  		handle_message_radio_status(msg);
  		break;
  
  	case MAVLINK_MSG_ID_MANUAL_CONTROL:
  		handle_message_manual_control(msg);
  		break;
  
  	case MAVLINK_MSG_ID_RC_CHANNELS_OVERRIDE:
  		handle_message_rc_channels_override(msg);
  		break;
  
  	case MAVLINK_MSG_ID_HEARTBEAT:
  		handle_message_heartbeat(msg);
  		break;
  
  	case MAVLINK_MSG_ID_REQUEST_DATA_STREAM:
  		if (_mavlink->accepting_commands()) {
  			handle_message_request_data_stream(msg);
  		}
  
  		break;
  
  	case MAVLINK_MSG_ID_SYSTEM_TIME:
  		handle_message_system_time(msg);
  		break;
  
  	case MAVLINK_MSG_ID_TIMESYNC:
  		handle_message_timesync(msg);
  		break;
  
  	case MAVLINK_MSG_ID_DISTANCE_SENSOR:
  		handle_message_distance_sensor(msg);
  		break;
  
  	case MAVLINK_MSG_ID_FOLLOW_TARGET:
  		handle_message_follow_target(msg);
  		break;
  
  	case MAVLINK_MSG_ID_ADSB_VEHICLE:
  		handle_message_adsb_vehicle(msg);
  		break;
  
  	case MAVLINK_MSG_ID_COLLISION:
  		handle_message_collision(msg);
  		break;
  
  	case MAVLINK_MSG_ID_GPS_RTCM_DATA:
  		handle_message_gps_rtcm_data(msg);
  		break;
  
  	case MAVLINK_MSG_ID_BATTERY_STATUS:
  		handle_message_battery_status(msg);
  		break;
  
  	case MAVLINK_MSG_ID_SERIAL_CONTROL:
  		handle_message_serial_control(msg);
  		break;
  
  	case MAVLINK_MSG_ID_LOGGING_ACK:
  		handle_message_logging_ack(msg);
  		break;
  
  	case MAVLINK_MSG_ID_PLAY_TUNE:
  		handle_message_play_tune(msg);
  		break;
  
  	default:
  		break;
  	}
  
  	/*
  	 * Only decode hil messages in HIL mode.
  	 *
  	 * The HIL mode is enabled by the HIL bit flag
  	 * in the system mode. Either send a set mode
  	 * COMMAND_LONG message or a SET_MODE message
  	 *
  	 * Accept HIL GPS messages if use_hil_gps flag is true.
  	 * This allows to provide fake gps measurements to the system.
  	 */
  	if (_mavlink->get_hil_enabled()) {
  		switch (msg->msgid) {
  		case MAVLINK_MSG_ID_HIL_SENSOR:
  			handle_message_hil_sensor(msg);
  			break;
  
  		case MAVLINK_MSG_ID_HIL_STATE_QUATERNION:
  			handle_message_hil_state_quaternion(msg);
  			break;
  
  		case MAVLINK_MSG_ID_HIL_OPTICAL_FLOW:
  			handle_message_hil_optical_flow(msg);
  			break;
  
  		default:
  			break;
  		}
  	}
  
  
  	if (_mavlink->get_hil_enabled() || (_mavlink->get_use_hil_gps() && msg->sysid == mavlink_system.sysid)) {
  		switch (msg->msgid) {
  		case MAVLINK_MSG_ID_HIL_GPS:
  			handle_message_hil_gps(msg);
  			break;
  
  		default:
  			break;
  		}
  
  	}
  
  	/* If we've received a valid message, mark the flag indicating so.
  	   This is used in the '-w' command-line flag. */
  	_mavlink->set_has_received_messages(true);
  }
  
  bool
  MavlinkReceiver::evaluate_target_ok(int command, int target_system, int target_component)
  {
  	/* evaluate if this system should accept this command */
  	bool target_ok = false;
  
  	switch (command) {
  
  	case MAV_CMD_REQUEST_AUTOPILOT_CAPABILITIES:
  		/* broadcast and ignore component */
  		target_ok = (target_system == 0) || (target_system == mavlink_system.sysid);
  		break;
  
  	default:
  		target_ok = (target_system == mavlink_system.sysid) && ((target_component == mavlink_system.compid)
  				|| (target_component == MAV_COMP_ID_ALL));
  		break;
  	}
  
  	return target_ok;
  }
  
  void
  MavlinkReceiver::handle_message_command_long(mavlink_message_t *msg)
  {
  	/* command */
  	mavlink_command_long_t cmd_mavlink;
  	mavlink_msg_command_long_decode(msg, &cmd_mavlink);
  
  	bool target_ok = evaluate_target_ok(cmd_mavlink.command, cmd_mavlink.target_system, cmd_mavlink.target_component);
  
  	bool send_ack = true;
  	int ret = 0;
  
  	if (!target_ok) {
  		ret = PX4_ERROR;
  		goto out;
  	}
  
  	//check for MAVLINK terminate command
  	if (cmd_mavlink.command == MAV_CMD_PREFLIGHT_REBOOT_SHUTDOWN && ((int)cmd_mavlink.param1) == 10) {
  		/* This is the link shutdown command, terminate mavlink */
  		warnx("terminated by remote");
  		fflush(stdout);
  		usleep(50000);
  
  		/* terminate other threads and this thread */
  		_mavlink->_task_should_exit = true;
  
  	} else if (cmd_mavlink.command == MAV_CMD_REQUEST_AUTOPILOT_CAPABILITIES) {
  		/* send autopilot version message */
  		_mavlink->send_autopilot_capabilites();
  
  	} else if (cmd_mavlink.command == MAV_CMD_GET_HOME_POSITION) {
  		_mavlink->configure_stream_threadsafe("HOME_POSITION", 0.5f);
  
  	} else if (cmd_mavlink.command == MAV_CMD_SET_MESSAGE_INTERVAL) {
  		ret = set_message_interval((int)(cmd_mavlink.param1 + 0.5f),
  					   cmd_mavlink.param2, cmd_mavlink.param3);
  
  	} else if (cmd_mavlink.command == MAV_CMD_GET_MESSAGE_INTERVAL) {
  		get_message_interval((int)cmd_mavlink.param1);
  
  	} else {
  
  		send_ack = false;
  
  		if (msg->sysid == mavlink_system.sysid && msg->compid == mavlink_system.compid) {
  			PX4_WARN("ignoring CMD with same SYS/COMP (%d/%d) ID",
  				 mavlink_system.sysid, mavlink_system.compid);
  			return;
  		}
  
  		if (cmd_mavlink.command == MAV_CMD_LOGGING_START) {
  			// we already instanciate the streaming object, because at this point we know on which
  			// mavlink channel streaming was requested. But in fact it's possible that the logger is
  			// not even running. The main mavlink thread takes care of this by waiting for an ack
  			// from the logger.
  			_mavlink->try_start_ulog_streaming(msg->sysid, msg->compid);
  
  		} else if (cmd_mavlink.command == MAV_CMD_LOGGING_STOP) {
  			_mavlink->request_stop_ulog_streaming();
  		}
  
  		struct vehicle_command_s vcmd;
  
  		memset(&vcmd, 0, sizeof(vcmd));
  
  		/* Copy the content of mavlink_command_long_t cmd_mavlink into command_t cmd */
  		vcmd.param1 = cmd_mavlink.param1;
  
  		vcmd.param2 = cmd_mavlink.param2;
  
  		vcmd.param3 = cmd_mavlink.param3;
  
  		vcmd.param4 = cmd_mavlink.param4;
  
  		vcmd.param5 = cmd_mavlink.param5;
  
  		vcmd.param6 = cmd_mavlink.param6;
  
  		vcmd.param7 = cmd_mavlink.param7;
  
  		// XXX do proper translation
  		vcmd.command = cmd_mavlink.command;
  
  		vcmd.target_system = cmd_mavlink.target_system;
  
  		vcmd.target_component = cmd_mavlink.target_component;
  
  		vcmd.source_system = msg->sysid;
  
  		vcmd.source_component = msg->compid;
  
  		vcmd.confirmation =  cmd_mavlink.confirmation;
  
  		if (_cmd_pub == nullptr) {
  			_cmd_pub = orb_advertise_queue(ORB_ID(vehicle_command), &vcmd, vehicle_command_s::ORB_QUEUE_LENGTH);
  
  		} else {
  			orb_publish(ORB_ID(vehicle_command), _cmd_pub, &vcmd);
  		}
  	}
  
  out:
  
  	if (send_ack) {
  		vehicle_command_ack_s command_ack;
  		command_ack.command = cmd_mavlink.command;
  
  		if (ret == PX4_OK) {
  			command_ack.result = vehicle_command_ack_s::VEHICLE_RESULT_ACCEPTED;
  
  		} else {
  			command_ack.result = vehicle_command_ack_s::VEHICLE_RESULT_FAILED;
  		}
  
  		if (_command_ack_pub == nullptr) {
  			_command_ack_pub = orb_advertise_queue(ORB_ID(vehicle_command_ack), &command_ack,
  							       vehicle_command_ack_s::ORB_QUEUE_LENGTH);
  
  		} else {
  			orb_publish(ORB_ID(vehicle_command_ack), _command_ack_pub, &command_ack);
  		}
  	}
  }
  
  void
  MavlinkReceiver::handle_message_command_int(mavlink_message_t *msg)
  {
  	/* command */
  	mavlink_command_int_t cmd_mavlink;
  	mavlink_msg_command_int_decode(msg, &cmd_mavlink);
  
  	bool target_ok = evaluate_target_ok(cmd_mavlink.command, cmd_mavlink.target_system, cmd_mavlink.target_component);
  
  	bool send_ack = true;
  	int ret = 0;
  
  	if (!target_ok) {
  		ret = PX4_ERROR;
  		goto out;
  	}
  
  	//check for MAVLINK terminate command
  	if (cmd_mavlink.command == MAV_CMD_PREFLIGHT_REBOOT_SHUTDOWN && ((int)cmd_mavlink.param1) == 10) {
  		/* This is the link shutdown command, terminate mavlink */
  		PX4_WARN("terminated by remote");
  		fflush(stdout);
  		usleep(50000);
  
  		/* terminate other threads and this thread */
  		_mavlink->_task_should_exit = true;
  
  	} else if (cmd_mavlink.command == MAV_CMD_REQUEST_AUTOPILOT_CAPABILITIES) {
  		/* send autopilot version message */
  		_mavlink->send_autopilot_capabilites();
  
  	} else if (cmd_mavlink.command == MAV_CMD_GET_HOME_POSITION) {
  		_mavlink->configure_stream_threadsafe("HOME_POSITION", 0.5f);
  
  	} else {
  
  		if (msg->sysid == mavlink_system.sysid && msg->compid == mavlink_system.compid) {
  			PX4_WARN("ignoring CMD with same SYS/COMP (%d/%d) ID",
  				 mavlink_system.sysid, mavlink_system.compid);
  			return;
  		}
  
  		send_ack = false;
  
  		struct vehicle_command_s vcmd;
  
  		memset(&vcmd, 0, sizeof(vcmd));
  
  		/* Copy the content of mavlink_command_int_t cmd_mavlink into command_t cmd */
  		vcmd.param1 = cmd_mavlink.param1;
  
  		vcmd.param2 = cmd_mavlink.param2;
  
  		vcmd.param3 = cmd_mavlink.param3;
  
  		vcmd.param4 = cmd_mavlink.param4;
  
  		/* these are coordinates as 1e7 scaled integers to work around the 32 bit floating point limits */
  		vcmd.param5 = ((double)cmd_mavlink.x) / 1e7;
  
  		vcmd.param6 = ((double)cmd_mavlink.y) / 1e7;
  
  		vcmd.param7 = cmd_mavlink.z;
  
  		// XXX do proper translation
  		vcmd.command = cmd_mavlink.command;
  
  		vcmd.target_system = cmd_mavlink.target_system;
  
  		vcmd.target_component = cmd_mavlink.target_component;
  
  		vcmd.source_system = msg->sysid;
  
  		vcmd.source_component = msg->compid;
  
  		if (_cmd_pub == nullptr) {
  			_cmd_pub = orb_advertise_queue(ORB_ID(vehicle_command), &vcmd, vehicle_command_s::ORB_QUEUE_LENGTH);
  
  		} else {
  			orb_publish(ORB_ID(vehicle_command), _cmd_pub, &vcmd);
  		}
  	}
  
  out:
  
  	if (send_ack) {
  		vehicle_command_ack_s command_ack;
  		command_ack.command = cmd_mavlink.command;
  
  		if (ret == PX4_OK) {
  			command_ack.result = vehicle_command_ack_s::VEHICLE_RESULT_ACCEPTED;
  
  		} else {
  			command_ack.result = vehicle_command_ack_s::VEHICLE_RESULT_FAILED;
  		}
  
  		if (_command_ack_pub == nullptr) {
  			_command_ack_pub = orb_advertise_queue(ORB_ID(vehicle_command_ack), &command_ack,
  							       vehicle_command_ack_s::ORB_QUEUE_LENGTH);
  
  		} else {
  			orb_publish(ORB_ID(vehicle_command_ack), _command_ack_pub, &command_ack);
  		}
  	}
  }
  
  void
  MavlinkReceiver::handle_message_optical_flow_rad(mavlink_message_t *msg)
  {
  	/* optical flow */
  	mavlink_optical_flow_rad_t flow;
  	mavlink_msg_optical_flow_rad_decode(msg, &flow);
  
  	enum Rotation flow_rot;
  	param_get(param_find("SENS_FLOW_ROT"), &flow_rot);
  
  	struct optical_flow_s f = {};
  
  	f.timestamp = flow.time_usec;
  	f.integration_timespan = flow.integration_time_us;
  	f.pixel_flow_x_integral = flow.integrated_x;
  	f.pixel_flow_y_integral = flow.integrated_y;
  	f.gyro_x_rate_integral = flow.integrated_xgyro;
  	f.gyro_y_rate_integral = flow.integrated_ygyro;
  	f.gyro_z_rate_integral = flow.integrated_zgyro;
  	f.time_since_last_sonar_update = flow.time_delta_distance_us;
  	f.ground_distance_m = flow.distance;
  	f.quality = flow.quality;
  	f.sensor_id = flow.sensor_id;
  	f.gyro_temperature = flow.temperature;
  
  	/* rotate measurements according to parameter */
  	float zeroval = 0.0f;
  	rotate_3f(flow_rot, f.pixel_flow_x_integral, f.pixel_flow_y_integral, zeroval);
  	rotate_3f(flow_rot, f.gyro_x_rate_integral, f.gyro_y_rate_integral, f.gyro_z_rate_integral);
  
  	if (_flow_pub == nullptr) {
  		_flow_pub = orb_advertise(ORB_ID(optical_flow), &f);
  
  	} else {
  		orb_publish(ORB_ID(optical_flow), _flow_pub, &f);
  	}
  
  	/* Use distance value for distance sensor topic */
  	struct distance_sensor_s d = {};
  
  	if (flow.distance > 0.0f) { // negative values signal invalid data
  		d.timestamp = flow.integration_time_us * 1000; /* ms to us */
  		d.min_distance = 0.3f;
  		d.max_distance = 5.0f;
  		d.current_distance = flow.distance; /* both are in m */
  		d.type = 1;
  		d.id = MAV_DISTANCE_SENSOR_ULTRASOUND;
  		d.orientation = 8;
  		d.covariance = 0.0;
  
  		if (_flow_distance_sensor_pub == nullptr) {
  			_flow_distance_sensor_pub = orb_advertise_multi(ORB_ID(distance_sensor), &d,
  						    &_orb_class_instance, ORB_PRIO_HIGH);
  
  		} else {
  			orb_publish(ORB_ID(distance_sensor), _flow_distance_sensor_pub, &d);
  		}
  	}
  }
  
  void
  MavlinkReceiver::handle_message_hil_optical_flow(mavlink_message_t *msg)
  {
  	/* optical flow */
  	mavlink_hil_optical_flow_t flow;
  	mavlink_msg_hil_optical_flow_decode(msg, &flow);
  
  	struct optical_flow_s f;
  	memset(&f, 0, sizeof(f));
  
  	f.timestamp = hrt_absolute_time(); // XXX we rely on the system time for now and not flow.time_usec;
  	f.integration_timespan = flow.integration_time_us;
  	f.pixel_flow_x_integral = flow.integrated_x;
  	f.pixel_flow_y_integral = flow.integrated_y;
  	f.gyro_x_rate_integral = flow.integrated_xgyro;
  	f.gyro_y_rate_integral = flow.integrated_ygyro;
  	f.gyro_z_rate_integral = flow.integrated_zgyro;
  	f.time_since_last_sonar_update = flow.time_delta_distance_us;
  	f.ground_distance_m = flow.distance;
  	f.quality = flow.quality;
  	f.sensor_id = flow.sensor_id;
  	f.gyro_temperature = flow.temperature;
  
  	if (_flow_pub == nullptr) {
  		_flow_pub = orb_advertise(ORB_ID(optical_flow), &f);
  
  	} else {
  		orb_publish(ORB_ID(optical_flow), _flow_pub, &f);
  	}
  
  	/* Use distance value for distance sensor topic */
  	struct distance_sensor_s d;
  	memset(&d, 0, sizeof(d));
  
  	d.timestamp = hrt_absolute_time();
  	d.min_distance = 0.3f;
  	d.max_distance = 5.0f;
  	d.current_distance = flow.distance; /* both are in m */
  	d.type = 1;
  	d.id = 0;
  	d.orientation = 8;
  	d.covariance = 0.0;
  
  	if (_hil_distance_sensor_pub == nullptr) {
  		_hil_distance_sensor_pub = orb_advertise_multi(ORB_ID(distance_sensor), &d,
  					   &_orb_class_instance, ORB_PRIO_HIGH);
  
  	} else {
  		orb_publish(ORB_ID(distance_sensor), _hil_distance_sensor_pub, &d);
  	}
  }
  
  void
  MavlinkReceiver::handle_message_set_mode(mavlink_message_t *msg)
  {
  	mavlink_set_mode_t new_mode;
  	mavlink_msg_set_mode_decode(msg, &new_mode);
  
  	struct vehicle_command_s vcmd;
  	memset(&vcmd, 0, sizeof(vcmd));
  
  	union px4_custom_mode custom_mode;
  	custom_mode.data = new_mode.custom_mode;
  	/* copy the content of mavlink_command_long_t cmd_mavlink into command_t cmd */
  	vcmd.param1 = new_mode.base_mode;
  	vcmd.param2 = custom_mode.main_mode;
  	vcmd.param3 = custom_mode.sub_mode;
  	vcmd.param4 = 0;
  	vcmd.param5 = 0;
  	vcmd.param6 = 0;
  	vcmd.param7 = 0;
  	vcmd.command = vehicle_command_s::VEHICLE_CMD_DO_SET_MODE;
  	vcmd.target_system = new_mode.target_system;
  	vcmd.target_component = MAV_COMP_ID_ALL;
  	vcmd.source_system = msg->sysid;
  	vcmd.source_component = msg->compid;
  	vcmd.confirmation = 1;
  
  	if (_cmd_pub == nullptr) {
  		_cmd_pub = orb_advertise_queue(ORB_ID(vehicle_command), &vcmd, vehicle_command_s::ORB_QUEUE_LENGTH);
  
  	} else {
  		orb_publish(ORB_ID(vehicle_command), _cmd_pub, &vcmd);
  	}
  }
  
  void
  MavlinkReceiver::handle_message_distance_sensor(mavlink_message_t *msg)
  {
  	/* distance sensor */
  	mavlink_distance_sensor_t dist_sensor;
  	mavlink_msg_distance_sensor_decode(msg, &dist_sensor);
  
  	struct distance_sensor_s d;
  	memset(&d, 0, sizeof(d));
  
  	d.timestamp = dist_sensor.time_boot_ms * 1000; /* ms to us */
  	d.min_distance = float(dist_sensor.min_distance) * 1e-2f; /* cm to m */
  	d.max_distance = float(dist_sensor.max_distance) * 1e-2f; /* cm to m */
  	d.current_distance = float(dist_sensor.current_distance) * 1e-2f; /* cm to m */
  	d.type = dist_sensor.type;
  	d.id = 	MAV_DISTANCE_SENSOR_LASER;
  	d.orientation = dist_sensor.orientation;
  	d.covariance = dist_sensor.covariance;
  
  	/// TODO Add sensor rotation according to MAV_SENSOR_ORIENTATION enum
  
  	if (_distance_sensor_pub == nullptr) {
  		_distance_sensor_pub = orb_advertise_multi(ORB_ID(distance_sensor), &d,
  				       &_orb_class_instance, ORB_PRIO_HIGH);
  
  	} else {
  		orb_publish(ORB_ID(distance_sensor), _distance_sensor_pub, &d);
  	}
  }
  
  void
  MavlinkReceiver::handle_message_att_pos_mocap(mavlink_message_t *msg)
  {
  	mavlink_att_pos_mocap_t mocap;
  	mavlink_msg_att_pos_mocap_decode(msg, &mocap);
  
  	struct att_pos_mocap_s att_pos_mocap = {};
  
  	// Use the component ID to identify the mocap system
  	att_pos_mocap.id = msg->compid;
  
  	att_pos_mocap.timestamp = sync_stamp(mocap.time_usec);
  	att_pos_mocap.timestamp_received = hrt_absolute_time();
  
  	att_pos_mocap.q[0] = mocap.q[0];
  	att_pos_mocap.q[1] = mocap.q[1];
  	att_pos_mocap.q[2] = mocap.q[2];
  	att_pos_mocap.q[3] = mocap.q[3];
  
  	att_pos_mocap.x = mocap.x;
  	att_pos_mocap.y = mocap.y;
  	att_pos_mocap.z = mocap.z;
  
  	if (_att_pos_mocap_pub == nullptr) {
  		_att_pos_mocap_pub = orb_advertise(ORB_ID(att_pos_mocap), &att_pos_mocap);
  
  	} else {
  		orb_publish(ORB_ID(att_pos_mocap), _att_pos_mocap_pub, &att_pos_mocap);
  	}
  }
  
  void
  MavlinkReceiver::handle_message_set_position_target_local_ned(mavlink_message_t *msg)
  {
  	mavlink_set_position_target_local_ned_t set_position_target_local_ned;
  	mavlink_msg_set_position_target_local_ned_decode(msg, &set_position_target_local_ned);
  
  	struct offboard_control_mode_s offboard_control_mode = {};
  
  	bool values_finite =
  		PX4_ISFINITE(set_position_target_local_ned.x) &&
  		PX4_ISFINITE(set_position_target_local_ned.y) &&
  		PX4_ISFINITE(set_position_target_local_ned.z) &&
  		PX4_ISFINITE(set_position_target_local_ned.vx) &&
  		PX4_ISFINITE(set_position_target_local_ned.vy) &&
  		PX4_ISFINITE(set_position_target_local_ned.vz) &&
  		PX4_ISFINITE(set_position_target_local_ned.afx) &&
  		PX4_ISFINITE(set_position_target_local_ned.afy) &&
  		PX4_ISFINITE(set_position_target_local_ned.afz) &&
  		PX4_ISFINITE(set_position_target_local_ned.yaw);
  
  	/* Only accept messages which are intended for this system */
  	if ((mavlink_system.sysid == set_position_target_local_ned.target_system ||
  	     set_position_target_local_ned.target_system == 0) &&
  	    (mavlink_system.compid == set_position_target_local_ned.target_component ||
  	     set_position_target_local_ned.target_component == 0) &&
  	    values_finite) {
  
  		/* convert mavlink type (local, NED) to uORB offboard control struct */
  		offboard_control_mode.ignore_position = (bool)(set_position_target_local_ned.type_mask & 0x7);
  		offboard_control_mode.ignore_alt_hold = (bool)(set_position_target_local_ned.type_mask & 0x4);
  		offboard_control_mode.ignore_velocity = (bool)(set_position_target_local_ned.type_mask & 0x38);
  		offboard_control_mode.ignore_acceleration_force = (bool)(set_position_target_local_ned.type_mask & 0x1C0);
  		bool is_force_sp = (bool)(set_position_target_local_ned.type_mask & (1 << 9));
  		/* yaw ignore flag mapps to ignore_attitude */
  		offboard_control_mode.ignore_attitude = (bool)(set_position_target_local_ned.type_mask & 0x400);
  		/* yawrate ignore flag mapps to ignore_bodyrate */
  		offboard_control_mode.ignore_bodyrate = (bool)(set_position_target_local_ned.type_mask & 0x800);
  
  
  		bool is_takeoff_sp = (bool)(set_position_target_local_ned.type_mask & 0x1000);
  		bool is_land_sp = (bool)(set_position_target_local_ned.type_mask & 0x2000);
  		bool is_loiter_sp = (bool)(set_position_target_local_ned.type_mask & 0x3000);
  		bool is_idle_sp = (bool)(set_position_target_local_ned.type_mask & 0x4000);
  
  		offboard_control_mode.timestamp = hrt_absolute_time();
  
  		if (_offboard_control_mode_pub == nullptr) {
  			_offboard_control_mode_pub = orb_advertise(ORB_ID(offboard_control_mode), &offboard_control_mode);
  
  		} else {
  			orb_publish(ORB_ID(offboard_control_mode), _offboard_control_mode_pub, &offboard_control_mode);
  		}
  
  		/* If we are in offboard control mode and offboard control loop through is enabled
  		 * also publish the setpoint topic which is read by the controller */
  		if (_mavlink->get_forward_externalsp()) {
  			bool updated;
  			orb_check(_control_mode_sub, &updated);
  
  			if (updated) {
  				orb_copy(ORB_ID(vehicle_control_mode), _control_mode_sub, &_control_mode);
  			}
  
  			if (_control_mode.flag_control_offboard_enabled) {
  				if (is_force_sp && offboard_control_mode.ignore_position &&
  				    offboard_control_mode.ignore_velocity) {
  					/* The offboard setpoint is a force setpoint only, directly writing to the force
  					 * setpoint topic and not publishing the setpoint triplet topic */
  					struct vehicle_force_setpoint_s	force_sp;
  					force_sp.x = set_position_target_local_ned.afx;
  					force_sp.y = set_position_target_local_ned.afy;
  					force_sp.z = set_position_target_local_ned.afz;
  
  					//XXX: yaw
  					if (_force_sp_pub == nullptr) {
  						_force_sp_pub = orb_advertise(ORB_ID(vehicle_force_setpoint), &force_sp);
  
  					} else {
  						orb_publish(ORB_ID(vehicle_force_setpoint), _force_sp_pub, &force_sp);
  					}
  
  				} else {
  					/* It's not a pure force setpoint: publish to setpoint triplet  topic */
  					struct position_setpoint_triplet_s pos_sp_triplet = {};
  					pos_sp_triplet.timestamp = hrt_absolute_time();
  					pos_sp_triplet.previous.valid = false;
  					pos_sp_triplet.next.valid = false;
  					pos_sp_triplet.current.valid = true;
  
  					if (is_takeoff_sp) {
  						pos_sp_triplet.current.type = position_setpoint_s::SETPOINT_TYPE_TAKEOFF;
  
  					} else if (is_land_sp) {
  						pos_sp_triplet.current.type = position_setpoint_s::SETPOINT_TYPE_LAND;
  
  					} else if (is_loiter_sp) {
  						pos_sp_triplet.current.type = position_setpoint_s::SETPOINT_TYPE_LOITER;
  
  					} else if (is_idle_sp) {
  						pos_sp_triplet.current.type = position_setpoint_s::SETPOINT_TYPE_IDLE;
  
  					} else {
  						pos_sp_triplet.current.type = position_setpoint_s::SETPOINT_TYPE_POSITION;
  					}
  
  					/* set the local pos values */
  					if (!offboard_control_mode.ignore_position) {
  						pos_sp_triplet.current.position_valid = true;
  						pos_sp_triplet.current.x = set_position_target_local_ned.x;
  						pos_sp_triplet.current.y = set_position_target_local_ned.y;
  						pos_sp_triplet.current.z = set_position_target_local_ned.z;
  
  					} else {
  						pos_sp_triplet.current.position_valid = false;
  					}
  
  					/* set the local vel values */
  					if (!offboard_control_mode.ignore_velocity) {
  						pos_sp_triplet.current.velocity_valid = true;
  						pos_sp_triplet.current.vx = set_position_target_local_ned.vx;
  						pos_sp_triplet.current.vy = set_position_target_local_ned.vy;
  						pos_sp_triplet.current.vz = set_position_target_local_ned.vz;
  
  						pos_sp_triplet.current.velocity_frame =
  							set_position_target_local_ned.coordinate_frame;
  
  					} else {
  						pos_sp_triplet.current.velocity_valid = false;
  					}
  
  					if (!offboard_control_mode.ignore_alt_hold) {
  						pos_sp_triplet.current.alt_valid = true;
  						pos_sp_triplet.current.z = set_position_target_local_ned.z;
  
  					} else {
  						pos_sp_triplet.current.alt_valid = false;
  					}
  
  					/* set the local acceleration values if the setpoint type is 'local pos' and none
  					 * of the accelerations fields is set to 'ignore' */
  					if (!offboard_control_mode.ignore_acceleration_force) {
  						pos_sp_triplet.current.acceleration_valid = true;
  						pos_sp_triplet.current.a_x = set_position_target_local_ned.afx;
  						pos_sp_triplet.current.a_y = set_position_target_local_ned.afy;
  						pos_sp_triplet.current.a_z = set_position_target_local_ned.afz;
  						pos_sp_triplet.current.acceleration_is_force =
  							is_force_sp;
  
  					} else {
  						pos_sp_triplet.current.acceleration_valid = false;
  					}
  
  					/* set the yaw sp value */
  					if (!offboard_control_mode.ignore_attitude) {
  						pos_sp_triplet.current.yaw_valid = true;
  						pos_sp_triplet.current.yaw = set_position_target_local_ned.yaw;
  
  					} else {
  						pos_sp_triplet.current.yaw_valid = false;
  					}
  
  					/* set the yawrate sp value */
  					if (!offboard_control_mode.ignore_bodyrate) {
  						pos_sp_triplet.current.yawspeed_valid = true;
  						pos_sp_triplet.current.yawspeed = set_position_target_local_ned.yaw_rate;
  
  					} else {
  						pos_sp_triplet.current.yawspeed_valid = false;
  					}
  
  					//XXX handle global pos setpoints (different MAV frames)
  
  					if (_pos_sp_triplet_pub == nullptr) {
  						_pos_sp_triplet_pub = orb_advertise(ORB_ID(position_setpoint_triplet),
  										    &pos_sp_triplet);
  
  					} else {
  						orb_publish(ORB_ID(position_setpoint_triplet), _pos_sp_triplet_pub,
  							    &pos_sp_triplet);
  					}
  
  				}
  
  			}
  
  		}
  	}
  }
  
  void
  MavlinkReceiver::handle_message_set_actuator_control_target(mavlink_message_t *msg)
  {
  	mavlink_set_actuator_control_target_t set_actuator_control_target;
  	mavlink_msg_set_actuator_control_target_decode(msg, &set_actuator_control_target);
  
  	struct offboard_control_mode_s offboard_control_mode = {};
  
  	struct actuator_controls_s actuator_controls = {};
  
  	bool values_finite =
  		PX4_ISFINITE(set_actuator_control_target.controls[0]) &&
  		PX4_ISFINITE(set_actuator_control_target.controls[1]) &&
  		PX4_ISFINITE(set_actuator_control_target.controls[2]) &&
  		PX4_ISFINITE(set_actuator_control_target.controls[3]) &&
  		PX4_ISFINITE(set_actuator_control_target.controls[4]) &&
  		PX4_ISFINITE(set_actuator_control_target.controls[5]) &&
  		PX4_ISFINITE(set_actuator_control_target.controls[6]) &&
  		PX4_ISFINITE(set_actuator_control_target.controls[7]);
  
  	if ((mavlink_system.sysid == set_actuator_control_target.target_system ||
  	     set_actuator_control_target.target_system == 0) &&
  	    (mavlink_system.compid == set_actuator_control_target.target_component ||
  	     set_actuator_control_target.target_component == 0) &&
  	    values_finite) {
  
  		/* ignore all since we are setting raw actuators here */
  		offboard_control_mode.ignore_thrust             = true;
  		offboard_control_mode.ignore_attitude           = true;
  		offboard_control_mode.ignore_bodyrate           = true;
  		offboard_control_mode.ignore_position           = true;
  		offboard_control_mode.ignore_velocity           = true;
  		offboard_control_mode.ignore_acceleration_force = true;
  
  		offboard_control_mode.timestamp = hrt_absolute_time();
  
  		if (_offboard_control_mode_pub == nullptr) {
  			_offboard_control_mode_pub = orb_advertise(ORB_ID(offboard_control_mode), &offboard_control_mode);
  
  		} else {
  			orb_publish(ORB_ID(offboard_control_mode), _offboard_control_mode_pub, &offboard_control_mode);
  		}
  
  
  		/* If we are in offboard control mode, publish the actuator controls */
  		bool updated;
  		orb_check(_control_mode_sub, &updated);
  
  		if (updated) {
  			orb_copy(ORB_ID(vehicle_control_mode), _control_mode_sub, &_control_mode);
  		}
  
  		if (_control_mode.flag_control_offboard_enabled) {
  
  			actuator_controls.timestamp = hrt_absolute_time();
  
  			/* Set duty cycles for the servos in actuator_controls_0 */
  			for (size_t i = 0; i < 8; i++) {
  				actuator_controls.control[i] = set_actuator_control_target.controls[i];
  			}
  
  			if (_actuator_controls_pub == nullptr) {
  				_actuator_controls_pub = orb_advertise(ORB_ID(actuator_controls_0), &actuator_controls);
  
  			} else {
  				orb_publish(ORB_ID(actuator_controls_0), _actuator_controls_pub, &actuator_controls);
  			}
  		}
  	}
  
  }
  
  void
  MavlinkReceiver::handle_message_gps_global_origin(mavlink_message_t *msg)
  {
  	mavlink_gps_global_origin_t origin;
  	mavlink_msg_gps_global_origin_decode(msg, &origin);
  
  	if (!globallocalconverter_initialized()) {
  		/* Set reference point conversion of local coordiantes <--> global coordinates */
  		globallocalconverter_init((double)origin.latitude * 1.0e-7, (double)origin.longitude * 1.0e-7,
  					  (float)origin.altitude * 1.0e-3f, hrt_absolute_time());
  		_global_ref_timestamp = hrt_absolute_time();
  
  	}
  }
  
  void
  MavlinkReceiver::handle_message_attitude_quaternion_cov(mavlink_message_t *msg)
  {
  	mavlink_attitude_quaternion_cov_t att;
  	mavlink_msg_attitude_quaternion_cov_decode(msg, &att);
  
  	struct vehicle_attitude_s vision_attitude = {};
  
  	vision_attitude.timestamp = sync_stamp(att.time_usec);
  
  	vision_attitude.q[0] = att.q[0];
  	vision_attitude.q[1] = att.q[1];
  	vision_attitude.q[2] = att.q[2];
  	vision_attitude.q[3] = att.q[3];
  
  	vision_attitude.rollspeed = att.rollspeed;
  	vision_attitude.pitchspeed = att.pitchspeed;
  	vision_attitude.yawspeed = att.yawspeed;
  
  	// TODO : full covariance matrix
  
  	int instance_id = 0;
  	orb_publish_auto(ORB_ID(vehicle_vision_attitude), &_vision_attitude_pub, &vision_attitude, &instance_id, ORB_PRIO_HIGH);
  
  }
  
  void
  MavlinkReceiver::handle_message_local_position_ned_cov(mavlink_message_t *msg)
  {
  	mavlink_local_position_ned_cov_t pos;
  	mavlink_msg_local_position_ned_cov_decode(msg, &pos);
  
  	struct vehicle_local_position_s vision_position = {};
  
  	vision_position.timestamp = sync_stamp(pos.time_usec);
  
  	// Use the estimator type to identify the external estimate
  	vision_position.estimator_type = pos.estimator_type;
  
  	vision_position.xy_valid = true;
  	vision_position.z_valid = true;
  	vision_position.v_xy_valid = true;
  	vision_position.v_z_valid = true;
  
  	vision_position.x = pos.x;
  	vision_position.y = pos.y;
  	vision_position.z = pos.z;
  
  	vision_position.vx = pos.vx;
  	vision_position.vy = pos.vy;
  	vision_position.vz = pos.vz;
  
  	vision_position.ax = pos.ax;
  	vision_position.ay = pos.ay;
  	vision_position.az = pos.az;
  
  	// Low risk change for now. TODO : full covariance matrix
  	vision_position.eph = sqrtf(fmaxf(pos.covariance[0], pos.covariance[9]));
  	vision_position.epv = sqrtf(pos.covariance[17]);
  
  	vision_position.xy_global = globallocalconverter_initialized();
  	vision_position.z_global = globallocalconverter_initialized();
  	vision_position.ref_timestamp = _global_ref_timestamp;
  	globallocalconverter_getref(&vision_position.ref_lat, &vision_position.ref_lon, &vision_position.ref_alt);
  
  	vision_position.dist_bottom_valid = false;
  
  	int instance_id = 0;
  	orb_publish_auto(ORB_ID(vehicle_vision_position), &_vision_position_pub, &vision_position, &instance_id, ORB_PRIO_HIGH);
  
  }
  
  void
  MavlinkReceiver::handle_message_vision_position_estimate(mavlink_message_t *msg)
  {
  	mavlink_vision_position_estimate_t pos;
  	mavlink_msg_vision_position_estimate_decode(msg, &pos);
  
  	struct vehicle_local_position_s vision_position = {};
  
  	// Use the estimator type to identify the simple vision estimate
  	vision_position.estimator_type = MAV_ESTIMATOR_TYPE_VISION;
  
  	vision_position.timestamp = sync_stamp(pos.usec);
  	vision_position.x = pos.x;
  	vision_position.y = pos.y;
  	vision_position.z = pos.z;
  
  	struct vehicle_attitude_s vision_attitude = {};
  
  	vision_attitude.timestamp = sync_stamp(pos.usec);
  
  	matrix::Quatf q(matrix::Eulerf(pos.roll, pos.pitch, pos.yaw));
  	q.copyTo(vision_attitude.q);
  
  	int inst = 0;
  	orb_publish_auto(ORB_ID(vehicle_vision_position), &_vision_position_pub, &vision_position, &inst, ORB_PRIO_DEFAULT);
  	orb_publish_auto(ORB_ID(vehicle_vision_attitude), &_vision_attitude_pub, &vision_attitude, &inst, ORB_PRIO_DEFAULT);
  }
  
  void
  MavlinkReceiver::handle_message_set_attitude_target(mavlink_message_t *msg)
  {
  	mavlink_set_attitude_target_t set_attitude_target;
  	mavlink_msg_set_attitude_target_decode(msg, &set_attitude_target);
  
  	bool values_finite =
  		PX4_ISFINITE(set_attitude_target.q[0]) &&
  		PX4_ISFINITE(set_attitude_target.q[1]) &&
  		PX4_ISFINITE(set_attitude_target.q[2]) &&
  		PX4_ISFINITE(set_attitude_target.q[3]) &&
  		PX4_ISFINITE(set_attitude_target.thrust) &&
  		PX4_ISFINITE(set_attitude_target.body_roll_rate) &&
  		PX4_ISFINITE(set_attitude_target.body_pitch_rate) &&
  		PX4_ISFINITE(set_attitude_target.body_yaw_rate);
  
  	/* Only accept messages which are intended for this system */
  	if ((mavlink_system.sysid == set_attitude_target.target_system ||
  	     set_attitude_target.target_system == 0) &&
  	    (mavlink_system.compid == set_attitude_target.target_component ||
  	     set_attitude_target.target_component == 0) &&
  	    values_finite) {
  
  		/* set correct ignore flags for thrust field: copy from mavlink message */
  		_offboard_control_mode.ignore_thrust = (bool)(set_attitude_target.type_mask & (1 << 6));
  
  		/*
  		 * The tricky part in parsing this message is that the offboard sender *can* set attitude and thrust
  		 * using different messages. Eg.: First send set_attitude_target containing the attitude and ignore
  		 * bits set for everything else and then send set_attitude_target containing the thrust and ignore bits
  		 * set for everything else.
  		 */
  
  		/*
  		 * if attitude or body rate have been used (not ignored) previously and this message only sends
  		 * throttle and has the ignore bits set for attitude and rates don't change the flags for attitude and
  		 * body rates to keep the controllers running
  		 */
  		bool ignore_bodyrate_msg = (bool)(set_attitude_target.type_mask & 0x7);
  		bool ignore_attitude_msg = (bool)(set_attitude_target.type_mask & (1 << 7));
  
  		if (ignore_bodyrate_msg && ignore_attitude_msg && !_offboard_control_mode.ignore_thrust) {
  			/* Message want's us to ignore everything except thrust: only ignore if previously ignored */
  			_offboard_control_mode.ignore_bodyrate = ignore_bodyrate_msg && _offboard_control_mode.ignore_bodyrate;
  			_offboard_control_mode.ignore_attitude = ignore_attitude_msg && _offboard_control_mode.ignore_attitude;
  
  		} else {
  			_offboard_control_mode.ignore_bodyrate = ignore_bodyrate_msg;
  			_offboard_control_mode.ignore_attitude = ignore_attitude_msg;
  		}
  
  		_offboard_control_mode.ignore_position = true;
  		_offboard_control_mode.ignore_velocity = true;
  		_offboard_control_mode.ignore_acceleration_force = true;
  
  		_offboard_control_mode.timestamp = hrt_absolute_time();
  
  		if (_offboard_control_mode_pub == nullptr) {
  			_offboard_control_mode_pub = orb_advertise(ORB_ID(offboard_control_mode), &_offboard_control_mode);
  
  		} else {
  			orb_publish(ORB_ID(offboard_control_mode), _offboard_control_mode_pub, &_offboard_control_mode);
  		}
  
  		/* If we are in offboard control mode and offboard control loop through is enabled
  		 * also publish the setpoint topic which is read by the controller */
  		if (_mavlink->get_forward_externalsp()) {
  			bool updated;
  			orb_check(_control_mode_sub, &updated);
  
  			if (updated) {
  				orb_copy(ORB_ID(vehicle_control_mode), _control_mode_sub, &_control_mode);
  			}
  
  			if (_control_mode.flag_control_offboard_enabled) {
  
  				/* Publish attitude setpoint if attitude and thrust ignore bits are not set */
  				if (!(_offboard_control_mode.ignore_attitude)) {
  					_att_sp.timestamp = hrt_absolute_time();
  
  					if (!ignore_attitude_msg) { // only copy att sp if message contained new data
  						mavlink_quaternion_to_euler(set_attitude_target.q,
  									    &_att_sp.roll_body, &_att_sp.pitch_body, &_att_sp.yaw_body);
  						_att_sp.yaw_sp_move_rate = 0.0;
  						memcpy(_att_sp.q_d, set_attitude_target.q, sizeof(_att_sp.q_d));
  						_att_sp.q_d_valid = true;
  					}
  
  					if (!_offboard_control_mode.ignore_thrust) { // dont't overwrite thrust if it's invalid
  						_att_sp.thrust = set_attitude_target.thrust;
  					}
  
  					if (_att_sp_pub == nullptr) {
  						_att_sp_pub = orb_advertise(ORB_ID(vehicle_attitude_setpoint), &_att_sp);
  
  					} else {
  						orb_publish(ORB_ID(vehicle_attitude_setpoint), _att_sp_pub, &_att_sp);
  					}
  				}
  
  				/* Publish attitude rate setpoint if bodyrate and thrust ignore bits are not set */
  				///XXX add support for ignoring individual axes
  				if (!(_offboard_control_mode.ignore_bodyrate)) {
  					_rates_sp.timestamp = hrt_absolute_time();
  
  					if (!ignore_bodyrate_msg) { // only copy att rates sp if message contained new data
  						_rates_sp.roll = set_attitude_target.body_roll_rate;
  						_rates_sp.pitch = set_attitude_target.body_pitch_rate;
  						_rates_sp.yaw = set_attitude_target.body_yaw_rate;
  					}
  
  					if (!_offboard_control_mode.ignore_thrust) { // dont't overwrite thrust if it's invalid
  						_rates_sp.thrust = set_attitude_target.thrust;
  					}
  
  					if (_rates_sp_pub == nullptr) {
  						_rates_sp_pub = orb_advertise(ORB_ID(vehicle_rates_setpoint), &_rates_sp);
  
  					} else {
  						orb_publish(ORB_ID(vehicle_rates_setpoint), _rates_sp_pub, &_rates_sp);
  					}
  				}
  			}
  
  		}
  	}
  }
  
  void
  MavlinkReceiver::handle_message_radio_status(mavlink_message_t *msg)
  {
  	/* telemetry status supported only on first ORB_MULTI_MAX_INSTANCES mavlink channels */
  	if (_mavlink->get_channel() < (mavlink_channel_t)ORB_MULTI_MAX_INSTANCES) {
  		mavlink_radio_status_t rstatus;
  		mavlink_msg_radio_status_decode(msg, &rstatus);
  
  		struct telemetry_status_s &tstatus = _mavlink->get_rx_status();
  
  		tstatus.timestamp = hrt_absolute_time();
  		tstatus.telem_time = tstatus.timestamp;
  		/* tstatus.heartbeat_time is set by system heartbeats */
  		tstatus.type = telemetry_status_s::TELEMETRY_STATUS_RADIO_TYPE_3DR_RADIO;
  		tstatus.rssi = rstatus.rssi;
  		tstatus.remote_rssi = rstatus.remrssi;
  		tstatus.txbuf = rstatus.txbuf;
  		tstatus.noise = rstatus.noise;
  		tstatus.remote_noise = rstatus.remnoise;
  		tstatus.rxerrors = rstatus.rxerrors;
  		tstatus.fixed = rstatus.fixed;
  		tstatus.system_id = msg->sysid;
  		tstatus.component_id = msg->compid;
  
  		if (_telemetry_status_pub == nullptr) {
  			int multi_instance;
  			_telemetry_status_pub = orb_advertise_multi(ORB_ID(telemetry_status), &tstatus, &multi_instance, ORB_PRIO_HIGH);
  
  		} else {
  			orb_publish(ORB_ID(telemetry_status), _telemetry_status_pub, &tstatus);
  		}
  	}
  }
  
  void
  MavlinkReceiver::handle_message_battery_status(mavlink_message_t *msg)
  {
  	// external battery measurements
  	mavlink_battery_status_t battery_mavlink;
  	mavlink_msg_battery_status_decode(msg, &battery_mavlink);
  
  	battery_status_s battery_status = {};
  	battery_status.timestamp = hrt_absolute_time();
  
  	float voltage_sum = 0.0f;
  	uint8_t cell_count = 0;
  
  	while (battery_mavlink.voltages[cell_count] < UINT16_MAX && cell_count < 10) {
  		voltage_sum += (float)(battery_mavlink.voltages[cell_count]) / 1000.0f;
  		cell_count++;
  	}
  
  	battery_status.voltage_v = voltage_sum;
  	battery_status.voltage_filtered_v  = voltage_sum;
  	battery_status.current_a = battery_status.current_filtered_a = (float)(battery_mavlink.current_battery) / 100.0f;
  	battery_status.current_filtered_a = battery_status.current_a;
  	battery_status.remaining = (float)battery_mavlink.battery_remaining / 100.0f;
  	battery_status.discharged_mah = (float)battery_mavlink.current_consumed;
  	battery_status.cell_count = cell_count;
  	battery_status.connected = true;
  
  	// Get the battery level thresholds.
  	float bat_emergen_thr;
  	float bat_crit_thr;
  	float bat_low_thr;
  	param_get(_p_bat_emergen_thr, &bat_emergen_thr);
  	param_get(_p_bat_crit_thr, &bat_crit_thr);
  	param_get(_p_bat_low_thr, &bat_low_thr);
  
  	// Set the battery warning based on remaining charge.
  	//  Note: Smallest values must come first in evaluation.
  	if (battery_status.remaining < bat_emergen_thr) {
  		battery_status.warning = battery_status_s::BATTERY_WARNING_EMERGENCY;
  
  	} else if (battery_status.remaining < bat_crit_thr) {
  		battery_status.warning = battery_status_s::BATTERY_WARNING_CRITICAL;
  
  	} else if (battery_status.remaining < bat_low_thr) {
  		battery_status.warning = battery_status_s::BATTERY_WARNING_LOW;
  	}
  
  	if (_battery_pub == nullptr) {
  		_battery_pub = orb_advertise(ORB_ID(battery_status), &battery_status);
  
  	} else {
  		orb_publish(ORB_ID(battery_status), _battery_pub, &battery_status);
  	}
  }
  
  void
  MavlinkReceiver::handle_message_serial_control(mavlink_message_t *msg)
  {
  	mavlink_serial_control_t serial_control_mavlink;
  	mavlink_msg_serial_control_decode(msg, &serial_control_mavlink);
  
  	// we only support shell commands
  	if (serial_control_mavlink.device != SERIAL_CONTROL_DEV_SHELL
  	    || (serial_control_mavlink.flags & SERIAL_CONTROL_FLAG_REPLY)) {
  		return;
  	}
  
  	MavlinkShell *shell = _mavlink->get_shell();
  
  	if (shell) {
  		// we ignore the timeout, EXCLUSIVE & BLOCKING flags of the SERIAL_CONTROL message
  		if (serial_control_mavlink.count > 0) {
  			shell->write(serial_control_mavlink.data, serial_control_mavlink.count);
  		}
  
  		// if no response requested, assume the shell is no longer used
  		if ((serial_control_mavlink.flags & SERIAL_CONTROL_FLAG_RESPOND) == 0) {
  			_mavlink->close_shell();
  		}
  	}
  }
  
  void
  MavlinkReceiver::handle_message_logging_ack(mavlink_message_t *msg)
  {
  	mavlink_logging_ack_t logging_ack;
  	mavlink_msg_logging_ack_decode(msg, &logging_ack);
  
  	MavlinkULog *ulog_streaming = _mavlink->get_ulog_streaming();
  
  	if (ulog_streaming) {
  		ulog_streaming->handle_ack(logging_ack);
  	}
  }
  
  void
  MavlinkReceiver::handle_message_play_tune(mavlink_message_t *msg)
  {
  	mavlink_play_tune_t play_tune;
  	mavlink_msg_play_tune_decode(msg, &play_tune);
  
  	char *tune = play_tune.tune;
  
  	if ((mavlink_system.sysid == play_tune.target_system ||
  	     play_tune.target_system == 0) &&
  	    (mavlink_system.compid == play_tune.target_component ||
  	     play_tune.target_component == 0)) {
  
  		if (*tune == 'M') {
  			int fd = px4_open(TONEALARM0_DEVICE_PATH, PX4_F_WRONLY);
  
  			if (fd >= 0) {
  				px4_write(fd, tune, strlen(tune) + 1);
  				px4_close(fd);
  			}
  		}
  	}
  }
  
  switch_pos_t
  MavlinkReceiver::decode_switch_pos(uint16_t buttons, unsigned sw)
  {
  	// This 2-bit method should be used in the future: (buttons >> (sw * 2)) & 3;
  	return (buttons & (1 << sw)) ? manual_control_setpoint_s::SWITCH_POS_ON : manual_control_setpoint_s::SWITCH_POS_OFF;
  }
  
  int
  MavlinkReceiver::decode_switch_pos_n(uint16_t buttons, unsigned sw)
  {
  
  	bool on = (buttons & (1 << sw));
  
  	if (sw < MOM_SWITCH_COUNT) {
  
  		bool last_on = (_mom_switch_state & (1 << sw));
  
  		/* first switch is 2-pos, rest is 2 pos */
  		unsigned state_count = (sw == 0) ? 3 : 2;
  
  		/* only transition on low state */
  		if (!on && (on != last_on)) {
  
  			_mom_switch_pos[sw]++;
  
  			if (_mom_switch_pos[sw] == state_count) {
  				_mom_switch_pos[sw] = 0;
  			}
  		}
  
  		/* state_count - 1 is the number of intervals and 1000 is the range,
  		 * with 2 states 0 becomes 0, 1 becomes 1000. With
  		 * 3 states 0 becomes 0, 1 becomes 500, 2 becomes 1000,
  		 * and so on for more states.
  		 */
  		return (_mom_switch_pos[sw] * 1000) / (state_count - 1) + 1000;
  
  	} else {
  		/* return the current state */
  		return on * 1000 + 1000;
  	}
  }
  
  void
  MavlinkReceiver::handle_message_rc_channels_override(mavlink_message_t *msg)
  {
  	mavlink_rc_channels_override_t man;
  	mavlink_msg_rc_channels_override_decode(msg, &man);
  
  	// Check target
  	if (man.target_system != 0 && man.target_system != _mavlink->get_system_id()) {
  		return;
  	}
  
  	struct rc_input_values rc = {};
  
  	rc.timestamp = hrt_absolute_time();
  
  	rc.timestamp_last_signal = rc.timestamp;
  
  	rc.channel_count = 8;
  
  	rc.rc_failsafe = false;
  
  	rc.rc_lost = false;
  
  	rc.rc_lost_frame_count = 0;
  
  	rc.rc_total_frame_count = 1;
  
  	rc.rc_ppm_frame_length = 0;
  
  	rc.input_source = input_rc_s::RC_INPUT_SOURCE_MAVLINK;
  
  	rc.rssi = RC_INPUT_RSSI_MAX;
  
  	/* channels */
  	rc.values[0] = man.chan1_raw;
  
  	rc.values[1] = man.chan2_raw;
  
  	rc.values[2] = man.chan3_raw;
  
  	rc.values[3] = man.chan4_raw;
  
  	rc.values[4] = man.chan5_raw;
  
  	rc.values[5] = man.chan6_raw;
  
  	rc.values[6] = man.chan7_raw;
  
  	rc.values[7] = man.chan8_raw;
  
  	if (_rc_pub == nullptr) {
  		_rc_pub = orb_advertise(ORB_ID(input_rc), &rc);
  
  	} else {
  		orb_publish(ORB_ID(input_rc), _rc_pub, &rc);
  	}
  }
  
  void
  MavlinkReceiver::handle_message_manual_control(mavlink_message_t *msg)
  {
  	mavlink_manual_control_t man;
  	mavlink_msg_manual_control_decode(msg, &man);
  
  	// Check target
  	if (man.target != 0 && man.target != _mavlink->get_system_id()) {
  		return;
  	}
  
  	if (_mavlink->get_manual_input_mode_generation()) {
  
  		struct rc_input_values rc = {};
  		rc.timestamp = hrt_absolute_time();
  		rc.timestamp_last_signal = rc.timestamp;
  
  		rc.channel_count = 8;
  		rc.rc_failsafe = false;
  		rc.rc_lost = false;
  		rc.rc_lost_frame_count = 0;
  		rc.rc_total_frame_count = 1;
  		rc.rc_ppm_frame_length = 0;
  		rc.input_source = input_rc_s::RC_INPUT_SOURCE_MAVLINK;
  		rc.rssi = RC_INPUT_RSSI_MAX;
  
  		/* roll */
  		rc.values[0] = man.x / 2 + 1500;
  		/* pitch */
  		rc.values[1] = man.y / 2 + 1500;
  		/* yaw */
  		rc.values[2] = man.r / 2 + 1500;
  		/* throttle */
  		rc.values[3] = fminf(fmaxf(man.z / 0.9f + 800, 1000.0f), 2000.0f);
  
  		/* decode all switches which fit into the channel mask */
  		unsigned max_switch = (sizeof(man.buttons) * 8);
  		unsigned max_channels = (sizeof(rc.values) / sizeof(rc.values[0]));
  
  		if (max_switch > (max_channels - 4)) {
  			max_switch = (max_channels - 4);
  		}
  
  		/* fill all channels */
  		for (unsigned i = 0; i < max_switch; i++) {
  			rc.values[i + 4] = decode_switch_pos_n(man.buttons, i);
  		}
  
  		_mom_switch_state = man.buttons;
  
  		if (_rc_pub == nullptr) {
  			_rc_pub = orb_advertise(ORB_ID(input_rc), &rc);
  
  		} else {
  			orb_publish(ORB_ID(input_rc), _rc_pub, &rc);
  		}
  
  	} else {
  		struct manual_control_setpoint_s manual = {};
  
  		manual.timestamp = hrt_absolute_time();
  		manual.x = man.x / 1000.0f;
  		manual.y = man.y / 1000.0f;
  		manual.r = man.r / 1000.0f;
  		manual.z = man.z / 1000.0f;
  		manual.data_source = manual_control_setpoint_s::SOURCE_MAVLINK_0 + _mavlink->get_instance_id();
  
  		int m_inst;
  		orb_publish_auto(ORB_ID(manual_control_setpoint), &_manual_pub, &manual, &m_inst, ORB_PRIO_LOW);
  	}
  }
  
  void
  MavlinkReceiver::handle_message_heartbeat(mavlink_message_t *msg)
  {
  	/* telemetry status supported only on first TELEMETRY_STATUS_ORB_ID_NUM mavlink channels */
  	if (_mavlink->get_channel() < (mavlink_channel_t)ORB_MULTI_MAX_INSTANCES) {
  		mavlink_heartbeat_t hb;
  		mavlink_msg_heartbeat_decode(msg, &hb);
  
  		/* ignore own heartbeats, accept only heartbeats from GCS */
  		if (msg->sysid != mavlink_system.sysid && hb.type == MAV_TYPE_GCS) {
  
  			struct telemetry_status_s &tstatus = _mavlink->get_rx_status();
  
  			/* set heartbeat time and topic time and publish -
  			 * the telem status also gets updated on telemetry events
  			 */
  			tstatus.timestamp = hrt_absolute_time();
  			tstatus.heartbeat_time = tstatus.timestamp;
  
  			if (_telemetry_status_pub == nullptr) {
  				int multi_instance;
  				_telemetry_status_pub = orb_advertise_multi(ORB_ID(telemetry_status), &tstatus, &multi_instance, ORB_PRIO_HIGH);
  
  			} else {
  				orb_publish(ORB_ID(telemetry_status), _telemetry_status_pub, &tstatus);
  			}
  		}
  	}
  }
  
  void
  MavlinkReceiver::handle_message_ping(mavlink_message_t *msg)
  {
  	mavlink_ping_t ping;
  	mavlink_msg_ping_decode(msg, &ping);
  
  	if ((mavlink_system.sysid == ping.target_system) &&
  	    (mavlink_system.compid == ping.target_component)) {
  		mavlink_msg_ping_send_struct(_mavlink->get_channel(), &ping);
  	}
  }
  
  void
  MavlinkReceiver::handle_message_request_data_stream(mavlink_message_t *msg)
  {
  	// REQUEST_DATA_STREAM is deprecated, please use SET_MESSAGE_INTERVAL instead
  }
  
  int
  MavlinkReceiver::set_message_interval(int msgId, float interval, int data_rate)
  {
  	if (msgId == 0) {
  		return PX4_ERROR;
  	}
  
  	if (data_rate > 0) {
  		_mavlink->set_data_rate(data_rate);
  	}
  
  	// configure_stream wants a rate (msgs/second), so convert here.
  	float rate = 0;
  
  	if (interval < 0) {
  		// stop the stream.
  		rate = 0;
  
  	} else if (interval > 0) {
  		rate = 1000000.0f / interval;
  
  	} else {
  		// note: mavlink spec says rate == 0 is requesting a default rate but our streams
  		// don't publish a default rate so for now let's pick a default rate of zero.
  	}
  
  	bool found_id = false;
  
  
  	// The interval between two messages is in microseconds.
  	// Set to -1 to disable and 0 to request default rate
  	if (msgId != 0) {
  		for (unsigned int i = 0; streams_list[i] != nullptr; i++) {
  			const StreamListItem *item = streams_list[i];
  
  			if (msgId == item->get_id()) {
  				_mavlink->configure_stream_threadsafe(item->get_name(), rate);
  				found_id = true;
  				break;
  			}
  		}
  	}
  
  	return (found_id ? PX4_OK : PX4_ERROR);
  }
  
  void
  MavlinkReceiver::get_message_interval(int msgId)
  {
  	unsigned interval = 0;
  
  	MavlinkStream *stream = nullptr;
  	LL_FOREACH(_mavlink->get_streams(), stream) {
  		if (stream->get_id() == msgId) {
  			interval = stream->get_interval();
  			break;
  		}
  	}
  
  	// send back this value...
  	mavlink_msg_message_interval_send(_mavlink->get_channel(), msgId, interval);
  }
  
  void
  MavlinkReceiver::handle_message_system_time(mavlink_message_t *msg)
  {
  	mavlink_system_time_t time;
  	mavlink_msg_system_time_decode(msg, &time);
  
  	timespec tv = {};
  	px4_clock_gettime(CLOCK_REALTIME, &tv);
  
  	// date -d @1234567890: Sat Feb 14 02:31:30 MSK 2009
  	bool onb_unix_valid = (unsigned long long)tv.tv_sec > PX4_EPOCH_SECS;
  	bool ofb_unix_valid = time.time_unix_usec > PX4_EPOCH_SECS * 1000ULL;
  
  	if (!onb_unix_valid && ofb_unix_valid) {
  		tv.tv_sec = time.time_unix_usec / 1000000ULL;
  		tv.tv_nsec = (time.time_unix_usec % 1000000ULL) * 1000ULL;
  
  		if (px4_clock_settime(CLOCK_REALTIME, &tv)) {
  			warn("failed setting clock");
  
  		} else {
  			warnx("[timesync] UTC time synced.");
  		}
  	}
  
  }
  
  void
  MavlinkReceiver::handle_message_timesync(mavlink_message_t *msg)
  {
  	mavlink_timesync_t tsync = {};
  	mavlink_msg_timesync_decode(msg, &tsync);
  
  	struct time_offset_s tsync_offset = {};
  
  	uint64_t now_ns = hrt_absolute_time() * 1000LL ;
  
  	if (tsync.tc1 == 0) {
  
  		mavlink_timesync_t rsync; // return timestamped sync message
  
  		rsync.tc1 = now_ns;
  		rsync.ts1 = tsync.ts1;
  
  		mavlink_msg_timesync_send_struct(_mavlink->get_channel(), &rsync);
  
  		return;
  
  	} else if (tsync.tc1 > 0) {
  
  		int64_t offset_ns = (int64_t)(tsync.ts1 + now_ns - tsync.tc1 * 2) / 2 ;
  		int64_t dt = _time_offset - offset_ns;
  
  		if (dt > 10000000LL || dt < -10000000LL) { // 10 millisecond skew
  			_time_offset = offset_ns;
  			warnx("[timesync] Hard setting offset.");
  
  		} else {
  			smooth_time_offset(offset_ns);
  		}
  	}
  
  	tsync_offset.offset_ns = _time_offset ;
  
  	if (_time_offset_pub == nullptr) {
  		_time_offset_pub = orb_advertise(ORB_ID(time_offset), &tsync_offset);
  
  	} else {
  		orb_publish(ORB_ID(time_offset), _time_offset_pub, &tsync_offset);
  	}
  
  }
  
  void
  MavlinkReceiver::handle_message_hil_sensor(mavlink_message_t *msg)
  {
  	mavlink_hil_sensor_t imu;
  	mavlink_msg_hil_sensor_decode(msg, &imu);
  
  	uint64_t timestamp = hrt_absolute_time();
  
  	/* airspeed */
  	{
  		struct airspeed_s airspeed = {};
  
  		float ias = calc_indicated_airspeed(imu.diff_pressure * 1e2f);
  		float tas = calc_true_airspeed_from_indicated(ias, imu.abs_pressure * 100, imu.temperature);
  
  		airspeed.timestamp = timestamp;
  		airspeed.indicated_airspeed_m_s = ias;
  		airspeed.true_airspeed_m_s = tas;
  
  		if (_airspeed_pub == nullptr) {
  			_airspeed_pub = orb_advertise(ORB_ID(airspeed), &airspeed);
  
  		} else {
  			orb_publish(ORB_ID(airspeed), _airspeed_pub, &airspeed);
  		}
  	}
  
  	/* gyro */
  	{
  		struct gyro_report gyro = {};
  
  		gyro.timestamp = timestamp;
  		gyro.x_raw = imu.xgyro * 1000.0f;
  		gyro.y_raw = imu.ygyro * 1000.0f;
  		gyro.z_raw = imu.zgyro * 1000.0f;
  		gyro.x = imu.xgyro;
  		gyro.y = imu.ygyro;
  		gyro.z = imu.zgyro;
  		gyro.temperature = imu.temperature;
  
  		if (_gyro_pub == nullptr) {
  			_gyro_pub = orb_advertise(ORB_ID(sensor_gyro), &gyro);
  
  		} else {
  			orb_publish(ORB_ID(sensor_gyro), _gyro_pub, &gyro);
  		}
  	}
  
  	/* accelerometer */
  	{
  		struct accel_report accel = {};
  
  		accel.timestamp = timestamp;
  		accel.x_raw = imu.xacc / mg2ms2;
  		accel.y_raw = imu.yacc / mg2ms2;
  		accel.z_raw = imu.zacc / mg2ms2;
  		accel.x = imu.xacc;
  		accel.y = imu.yacc;
  		accel.z = imu.zacc;
  		accel.temperature = imu.temperature;
  
  		if (_accel_pub == nullptr) {
  			_accel_pub = orb_advertise(ORB_ID(sensor_accel), &accel);
  
  		} else {
  			orb_publish(ORB_ID(sensor_accel), _accel_pub, &accel);
  		}
  	}
  
  	/* magnetometer */
  	{
  		struct mag_report mag = {};
  
  		mag.timestamp = timestamp;
  		mag.x_raw = imu.xmag * 1000.0f;
  		mag.y_raw = imu.ymag * 1000.0f;
  		mag.z_raw = imu.zmag * 1000.0f;
  		mag.x = imu.xmag;
  		mag.y = imu.ymag;
  		mag.z = imu.zmag;
  
  		if (_mag_pub == nullptr) {
  			/* publish to the first mag topic */
  			_mag_pub = orb_advertise(ORB_ID(sensor_mag), &mag);
  
  		} else {
  			orb_publish(ORB_ID(sensor_mag), _mag_pub, &mag);
  		}
  	}
  
  	/* baro */
  	{
  		struct baro_report baro = {};
  
  		baro.timestamp = timestamp;
  		baro.pressure = imu.abs_pressure;
  		baro.altitude = imu.pressure_alt;
  		baro.temperature = imu.temperature;
  
  		/* fake device ID */
  		baro.device_id = 1234567;
  
  		if (_baro_pub == nullptr) {
  			_baro_pub = orb_advertise(ORB_ID(sensor_baro), &baro);
  
  		} else {
  			orb_publish(ORB_ID(sensor_baro), _baro_pub, &baro);
  		}
  	}
  
  	/* battery status */
  	{
  		struct battery_status_s hil_battery_status = {};
  
  		hil_battery_status.timestamp = timestamp;
  		hil_battery_status.voltage_v = 11.5f;
  		hil_battery_status.voltage_filtered_v = 11.5f;
  		hil_battery_status.current_a = 10.0f;
  		hil_battery_status.discharged_mah = -1.0f;
  
  		if (_battery_pub == nullptr) {
  			_battery_pub = orb_advertise(ORB_ID(battery_status), &hil_battery_status);
  
  		} else {
  			orb_publish(ORB_ID(battery_status), _battery_pub, &hil_battery_status);
  		}
  	}
  
  	/* increment counters */
  	_hil_frames++;
  
  	/* print HIL sensors rate */
  	if ((timestamp - _old_timestamp) > 10000000) {
  		// printf("receiving HIL sensors at %d hz\n", _hil_frames / 10);
  		_old_timestamp = timestamp;
  		_hil_frames = 0;
  	}
  }
  
  void
  MavlinkReceiver::handle_message_hil_gps(mavlink_message_t *msg)
  {
  	mavlink_hil_gps_t gps;
  	mavlink_msg_hil_gps_decode(msg, &gps);
  
  	uint64_t timestamp = hrt_absolute_time();
  
  	struct vehicle_gps_position_s hil_gps = {};
  
  	hil_gps.timestamp_time_relative = 0;
  	hil_gps.time_utc_usec = gps.time_usec;
  
  	hil_gps.timestamp = timestamp;
  	hil_gps.lat = gps.lat;
  	hil_gps.lon = gps.lon;
  	hil_gps.alt = gps.alt;
  	hil_gps.eph = (float)gps.eph * 1e-2f; // from cm to m
  	hil_gps.epv = (float)gps.epv * 1e-2f; // from cm to m
  
  	hil_gps.s_variance_m_s = 1.0f;
  
  	hil_gps.vel_m_s = (float)gps.vel * 1e-2f; // from cm/s to m/s
  	hil_gps.vel_n_m_s = gps.vn * 1e-2f; // from cm to m
  	hil_gps.vel_e_m_s = gps.ve * 1e-2f; // from cm to m
  	hil_gps.vel_d_m_s = gps.vd * 1e-2f; // from cm to m
  	hil_gps.vel_ned_valid = true;
  	hil_gps.cog_rad = _wrap_pi(gps.cog * M_DEG_TO_RAD_F * 1e-2f);
  
  	hil_gps.fix_type = gps.fix_type;
  	hil_gps.satellites_used = gps.satellites_visible;  //TODO: rename mavlink_hil_gps_t sats visible to used?
  
  	if (_gps_pub == nullptr) {
  		_gps_pub = orb_advertise(ORB_ID(vehicle_gps_position), &hil_gps);
  
  	} else {
  		orb_publish(ORB_ID(vehicle_gps_position), _gps_pub, &hil_gps);
  	}
  }
  
  void MavlinkReceiver::handle_message_follow_target(mavlink_message_t *msg)
  {
  	mavlink_follow_target_t follow_target_msg;
  	follow_target_s follow_target_topic = {};
  
  	mavlink_msg_follow_target_decode(msg, &follow_target_msg);
  
  	follow_target_topic.timestamp = hrt_absolute_time();
  
  	follow_target_topic.lat = follow_target_msg.lat * 1e-7;
  	follow_target_topic.lon = follow_target_msg.lon * 1e-7;
  	follow_target_topic.alt = follow_target_msg.alt;
  
  	if (_follow_target_pub == nullptr) {
  		_follow_target_pub = orb_advertise(ORB_ID(follow_target), &follow_target_topic);
  
  	} else {
  		orb_publish(ORB_ID(follow_target), _follow_target_pub, &follow_target_topic);
  	}
  }
  
  void MavlinkReceiver::handle_message_adsb_vehicle(mavlink_message_t *msg)
  {
  	mavlink_adsb_vehicle_t adsb;
  	transponder_report_s t = {};
  
  	mavlink_msg_adsb_vehicle_decode(msg, &adsb);
  
  	t.timestamp = hrt_absolute_time();
  
  	t.ICAO_address = adsb.ICAO_address;
  	t.lat = adsb.lat * 1e-7;
  	t.lon = adsb.lon * 1e-7;
  	t.altitude_type = adsb.altitude_type;
  	t.altitude = adsb.altitude / 1000.0f;
  	t.heading = adsb.heading / 100.0f / 180.0f * M_PI_F - M_PI_F;
  	t.hor_velocity = adsb.hor_velocity / 100.0f;
  	t.ver_velocity = adsb.ver_velocity / 100.0f;
  	memcpy(&t.callsign[0], &adsb.callsign[0], sizeof(t.callsign));
  	t.emitter_type = adsb.emitter_type;
  	t.tslc = adsb.tslc;
  	t.flags = adsb.flags;
  	t.squawk = adsb.squawk;
  
  	//warnx("code: %d callsign: %s, vel: %8.4f", (int)t.ICAO_address, t.callsign, (double)t.hor_velocity);
  
  	if (_transponder_report_pub == nullptr) {
  		_transponder_report_pub = orb_advertise(ORB_ID(transponder_report), &t);
  
  	} else {
  		orb_publish(ORB_ID(transponder_report), _transponder_report_pub, &t);
  	}
  }
  
  void MavlinkReceiver::handle_message_collision(mavlink_message_t *msg)
  {
  	mavlink_collision_t collision;
  	collision_report_s t = {};
  
  	mavlink_msg_collision_decode(msg, &collision);
  
  	t.timestamp = hrt_absolute_time();
  	t.src = collision.src;
  	t.id = collision.id;
  	t.action = collision.action;
  	t.threat_level = collision.threat_level;
  	t.time_to_minimum_delta = collision.time_to_minimum_delta;
  	t.altitude_minimum_delta = collision.altitude_minimum_delta;
  	t.horizontal_minimum_delta = collision.horizontal_minimum_delta;
  
  	if (_collision_report_pub == nullptr) {
  		_collision_report_pub = orb_advertise(ORB_ID(collision_report), &t);
  
  	} else {
  		orb_publish(ORB_ID(collision_report), _collision_report_pub, &t);
  	}
  }
  
  void MavlinkReceiver::handle_message_gps_rtcm_data(mavlink_message_t *msg)
  {
  	mavlink_gps_rtcm_data_t gps_rtcm_data_msg = {};
  	mavlink_msg_gps_rtcm_data_decode(msg, &gps_rtcm_data_msg);
  
  	gps_inject_data_s gps_inject_data_topic = {};
  	gps_inject_data_topic.len = math::min((int)sizeof(gps_rtcm_data_msg.data),
  					      (int)sizeof(uint8_t) * gps_rtcm_data_msg.len);
  	gps_inject_data_topic.flags = gps_rtcm_data_msg.flags;
  	memcpy(gps_inject_data_topic.data, gps_rtcm_data_msg.data,
  	       math::min((int)sizeof(gps_inject_data_topic.data), (int)sizeof(uint8_t) * gps_inject_data_topic.len));
  
  	orb_advert_t &pub = _gps_inject_data_pub;
  
  	if (pub == nullptr) {
  		pub = orb_advertise_queue(ORB_ID(gps_inject_data), &gps_inject_data_topic,
  					  _gps_inject_data_queue_size);
  
  	} else {
  		orb_publish(ORB_ID(gps_inject_data), pub, &gps_inject_data_topic);
  	}
  
  }
  
  void
  MavlinkReceiver::handle_message_hil_state_quaternion(mavlink_message_t *msg)
  {
  	mavlink_hil_state_quaternion_t hil_state;
  	mavlink_msg_hil_state_quaternion_decode(msg, &hil_state);
  
  	uint64_t timestamp = hrt_absolute_time();
  
  	/* airspeed */
  	{
  		struct airspeed_s airspeed = {};
  
  		airspeed.timestamp = timestamp;
  		airspeed.indicated_airspeed_m_s = hil_state.ind_airspeed * 1e-2f;
  		airspeed.true_airspeed_m_s = hil_state.true_airspeed * 1e-2f;
  
  		if (_airspeed_pub == nullptr) {
  			_airspeed_pub = orb_advertise(ORB_ID(airspeed), &airspeed);
  
  		} else {
  			orb_publish(ORB_ID(airspeed), _airspeed_pub, &airspeed);
  		}
  	}
  
  	/* attitude */
  	struct vehicle_attitude_s hil_attitude;
  	{
  		hil_attitude = {};
  		hil_attitude.timestamp = timestamp;
  
  		matrix::Quatf q(hil_state.attitude_quaternion);
  		q.copyTo(hil_attitude.q);
  
  		hil_attitude.rollspeed = hil_state.rollspeed;
  		hil_attitude.pitchspeed = hil_state.pitchspeed;
  		hil_attitude.yawspeed = hil_state.yawspeed;
  
  		if (_attitude_pub == nullptr) {
  			_attitude_pub = orb_advertise(ORB_ID(vehicle_attitude), &hil_attitude);
  
  		} else {
  			orb_publish(ORB_ID(vehicle_attitude), _attitude_pub, &hil_attitude);
  		}
  	}
  
  	/* global position */
  	{
  		struct vehicle_global_position_s hil_global_pos = {};
  		matrix::Eulerf euler = matrix::Quatf(hil_attitude.q);
  
  		hil_global_pos.timestamp = timestamp;
  		hil_global_pos.lat = hil_state.lat / ((double)1e7);
  		hil_global_pos.lon = hil_state.lon / ((double)1e7);
  		hil_global_pos.alt = hil_state.alt / 1000.0f;
  		hil_global_pos.vel_n = hil_state.vx / 100.0f;
  		hil_global_pos.vel_e = hil_state.vy / 100.0f;
  		hil_global_pos.vel_d = hil_state.vz / 100.0f;
  		hil_global_pos.yaw = euler.psi();
  		hil_global_pos.eph = 2.0f;
  		hil_global_pos.epv = 4.0f;
  
  		if (_global_pos_pub == nullptr) {
  			_global_pos_pub = orb_advertise(ORB_ID(vehicle_global_position), &hil_global_pos);
  
  		} else {
  			orb_publish(ORB_ID(vehicle_global_position), _global_pos_pub, &hil_global_pos);
  		}
  	}
  
  	/* local position */
  	{
  		double lat = hil_state.lat * 1e-7;
  		double lon = hil_state.lon * 1e-7;
  
  		if (!_hil_local_proj_inited) {
  			_hil_local_proj_inited = true;
  			_hil_local_alt0 = hil_state.alt / 1000.0f;
  			map_projection_init(&_hil_local_proj_ref, lat, lon);
  			_hil_local_pos.ref_timestamp = timestamp;
  			_hil_local_pos.ref_lat = lat;
  			_hil_local_pos.ref_lon = lon;
  			_hil_local_pos.ref_alt = _hil_local_alt0;
  		}
  
  		float x = 0.0f;
  		float y = 0.0f;
  		map_projection_project(&_hil_local_proj_ref, lat, lon, &x, &y);
  		_hil_local_pos.timestamp = timestamp;
  		_hil_local_pos.xy_valid = true;
  		_hil_local_pos.z_valid = true;
  		_hil_local_pos.v_xy_valid = true;
  		_hil_local_pos.v_z_valid = true;
  		_hil_local_pos.x = x;
  		_hil_local_pos.y = y;
  		_hil_local_pos.z = _hil_local_alt0 - hil_state.alt / 1000.0f;
  		_hil_local_pos.vx = hil_state.vx / 100.0f;
  		_hil_local_pos.vy = hil_state.vy / 100.0f;
  		_hil_local_pos.vz = hil_state.vz / 100.0f;
  		matrix::Eulerf euler = matrix::Quatf(hil_attitude.q);
  		_hil_local_pos.yaw = euler.psi();
  		_hil_local_pos.xy_global = true;
  		_hil_local_pos.z_global = true;
  
  		if (_local_pos_pub == nullptr) {
  			_local_pos_pub = orb_advertise(ORB_ID(vehicle_local_position), &_hil_local_pos);
  
  		} else {
  			orb_publish(ORB_ID(vehicle_local_position), _local_pos_pub, &_hil_local_pos);
  		}
  	}
  
  	/* land detector */
  	{
  		bool landed = (float)(hil_state.alt) / 1000.0f < (_hil_local_alt0 + 0.1f); // XXX improve?
  
  		if (_hil_land_detector.landed != landed) {
  			_hil_land_detector.landed = landed;
  			_hil_land_detector.timestamp = hrt_absolute_time();
  
  			if (_land_detector_pub == nullptr) {
  				_land_detector_pub = orb_advertise(ORB_ID(vehicle_land_detected), &_hil_land_detector);
  
  			} else {
  				orb_publish(ORB_ID(vehicle_land_detected), _land_detector_pub, &_hil_land_detector);
  			}
  		}
  	}
  
  	/* accelerometer */
  	{
  		struct accel_report accel = {};
  
  		accel.timestamp = timestamp;
  		accel.x_raw = hil_state.xacc / CONSTANTS_ONE_G * 1e3f;
  		accel.y_raw = hil_state.yacc / CONSTANTS_ONE_G * 1e3f;
  		accel.z_raw = hil_state.zacc / CONSTANTS_ONE_G * 1e3f;
  		accel.x = hil_state.xacc;
  		accel.y = hil_state.yacc;
  		accel.z = hil_state.zacc;
  		accel.temperature = 25.0f;
  
  		if (_accel_pub == nullptr) {
  			_accel_pub = orb_advertise(ORB_ID(sensor_accel), &accel);
  
  		} else {
  			orb_publish(ORB_ID(sensor_accel), _accel_pub, &accel);
  		}
  	}
  
  	/* battery status */
  	{
  		struct battery_status_s	hil_battery_status = {};
  
  		hil_battery_status.timestamp = timestamp;
  		hil_battery_status.voltage_v = 11.1f;
  		hil_battery_status.voltage_filtered_v = 11.1f;
  		hil_battery_status.current_a = 10.0f;
  		hil_battery_status.discharged_mah = -1.0f;
  
  		if (_battery_pub == nullptr) {
  			_battery_pub = orb_advertise(ORB_ID(battery_status), &hil_battery_status);
  
  		} else {
  			orb_publish(ORB_ID(battery_status), _battery_pub, &hil_battery_status);
  		}
  	}
  
  	/* control state */
  	control_state_s ctrl_state = {};
  	matrix::Quatf q(hil_state.attitude_quaternion);
  	matrix::Dcmf R_to_body(q.inversed());
  
  	//Time
  	ctrl_state.timestamp = hrt_absolute_time();
  
  	//Roll Rates:
  	//ctrl_state: body angular rate (rad/s, x forward/y right/z down)
  	//hil_state : body frame angular speed (rad/s)
  	ctrl_state.roll_rate = hil_state.rollspeed;
  	ctrl_state.pitch_rate = hil_state.pitchspeed;
  	ctrl_state.yaw_rate = hil_state.yawspeed;
  
  	// Local Position NED:
  	//ctrl_state: position in local earth frame
  	//hil_state : Latitude/Longitude expressed as * 1E7
  	float x = 0.0f;
  	float y = 0.0f;
  	double lat = hil_state.lat * 1e-7;
  	double lon = hil_state.lon * 1e-7;
  	map_projection_project(&_hil_local_proj_ref, lat, lon, &x, &y);
  	ctrl_state.x_pos = x;
  	ctrl_state.y_pos = y;
  	ctrl_state.z_pos = hil_state.alt / 1000.0f;
  
  	// Attitude quaternion
  	q.copyTo(ctrl_state.q);
  
  	// Velocity
  	//ctrl_state: velocity in body frame (x forward/y right/z down)
  	//hil_state : Ground Speed in NED expressed as m/s * 100
  	matrix::Vector3f v_n(hil_state.vx, hil_state.vy, hil_state.vz);
  	matrix::Vector3f v_b = R_to_body * v_n;
  	ctrl_state.x_vel = v_b(0) / 100.0f;
  	ctrl_state.y_vel = v_b(1) / 100.0f;
  	ctrl_state.z_vel = v_b(2) / 100.0f;
  
  	// Acceleration
  	//ctrl_state: acceleration in body frame
  	//hil_state : acceleration in body frame
  	ctrl_state.x_acc = hil_state.xacc;
  	ctrl_state.y_acc = hil_state.yacc;
  	ctrl_state.z_acc = hil_state.zacc;
  
  	static float _acc_hor_filt = 0;
  	_acc_hor_filt = 0.95f * _acc_hor_filt + 0.05f * sqrtf(ctrl_state.x_acc * ctrl_state.x_acc + ctrl_state.y_acc *
  			ctrl_state.y_acc);
  	ctrl_state.horz_acc_mag = _acc_hor_filt;
  	ctrl_state.airspeed_valid = false;
  
  	// publish control state data
  	if (_control_state_pub == nullptr) {
  		_control_state_pub = orb_advertise(ORB_ID(control_state), &ctrl_state);
  
  	} else {
  		orb_publish(ORB_ID(control_state), _control_state_pub, &ctrl_state);
  	}
  }
  
  /**
   * Receive data from UART.
   */
  void *
  MavlinkReceiver::receive_thread(void *arg)
  {
  
  	/* set thread name */
  	{
  		char thread_name[24];
  		sprintf(thread_name, "mavlink_rcv_if%d", _mavlink->get_instance_id());
  		px4_prctl(PR_SET_NAME, thread_name, px4_getpid());
  	}
  
  	// poll timeout in ms. Also defines the max update frequency of the mission & param manager, etc.
  	const int timeout = 10;
  
  #ifdef __PX4_POSIX
  	/* 1500 is the Wifi MTU, so we make sure to fit a full packet */
  	uint8_t buf[1600 * 5];
  #else
  	/* the serial port buffers internally as well, we just need to fit a small chunk */
  	uint8_t buf[64];
  #endif
  	mavlink_message_t msg;
  
  	struct pollfd fds[1] = {};
  
  	if (_mavlink->get_protocol() == SERIAL) {
  		fds[0].fd = _mavlink->get_uart_fd();
  		fds[0].events = POLLIN;
  	}
  
  #ifdef __PX4_POSIX
  	struct sockaddr_in srcaddr = {};
  	socklen_t addrlen = sizeof(srcaddr);
  
  	if (_mavlink->get_protocol() == UDP || _mavlink->get_protocol() == TCP) {
  		// make sure mavlink app has booted before we start using the socket
  		while (!_mavlink->boot_complete()) {
  			usleep(100000);
  		}
  
  		fds[0].fd = _mavlink->get_socket_fd();
  		fds[0].events = POLLIN;
  	}
  
  #endif
  	ssize_t nread = 0;
  	hrt_abstime last_send_update = 0;
  
  	while (!_mavlink->_task_should_exit) {
  		if (poll(&fds[0], 1, timeout) > 0) {
  			if (_mavlink->get_protocol() == SERIAL) {
  
  				/*
  				 * to avoid reading very small chunks wait for data before reading
  				 * this is designed to target one message, so >20 bytes at a time
  				 */
  				const unsigned character_count = 20;
  
  				/* non-blocking read. read may return negative values */
  				if ((nread = ::read(fds[0].fd, buf, sizeof(buf))) < (ssize_t)character_count) {
  					unsigned sleeptime = (1.0f / (_mavlink->get_baudrate() / 10)) * character_count * 1000000;
  					usleep(sleeptime);
  				}
  			}
  
  #ifdef __PX4_POSIX
  
  			if (_mavlink->get_protocol() == UDP) {
  				if (fds[0].revents & POLLIN) {
  					nread = recvfrom(_mavlink->get_socket_fd(), buf, sizeof(buf), 0, (struct sockaddr *)&srcaddr, &addrlen);
  				}
  
  			} else {
  				// could be TCP or other protocol
  			}
  
  			struct sockaddr_in *srcaddr_last = _mavlink->get_client_source_address();
  
  			int localhost = (127 << 24) + 1;
  
  			if (!_mavlink->get_client_source_initialized()) {
  
  				// set the address either if localhost or if 3 seconds have passed
  				// this ensures that a GCS running on localhost can get a hold of
  				// the system within the first N seconds
  				hrt_abstime stime = _mavlink->get_start_time();
  
  				if ((stime != 0 && (hrt_elapsed_time(&stime) > 3 * 1000 * 1000))
  				    || (srcaddr_last->sin_addr.s_addr == htonl(localhost))) {
  					srcaddr_last->sin_addr.s_addr = srcaddr.sin_addr.s_addr;
  					srcaddr_last->sin_port = srcaddr.sin_port;
  					_mavlink->set_client_source_initialized();
  					PX4_INFO("partner IP: %s", inet_ntoa(srcaddr.sin_addr));
  				}
  			}
  
  #endif
  			// only start accepting messages once we're sure who we talk to
  
  			if (_mavlink->get_client_source_initialized()) {
  				/* if read failed, this loop won't execute */
  				for (ssize_t i = 0; i < nread; i++) {
  					if (mavlink_parse_char(_mavlink->get_channel(), buf[i], &msg, &_status)) {
  
  						/* check if we received version 2 and request a switch. */
  						if (!(_mavlink->get_status()->flags & MAVLINK_STATUS_FLAG_IN_MAVLINK1)) {
  							/* this will only switch to proto version 2 if allowed in settings */
  							_mavlink->set_proto_version(2);
  						}
  
  						/* handle generic messages and commands */
  						handle_message(&msg);
  
  						/* handle packet with mission manager */
  						_mission_manager.handle_message(&msg);
  
  						/* handle packet with parameter component */
  						_parameters_manager.handle_message(&msg);
  
  						/* handle packet with ftp component */
  						_mavlink_ftp.handle_message(&msg);
  
  						/* handle packet with log component */
  						_mavlink_log_handler.handle_message(&msg);
  
  						/* handle packet with parent object */
  						_mavlink->handle_message(&msg);
  					}
  				}
  
  				/* count received bytes (nread will be -1 on read error) */
  				if (nread > 0) {
  					_mavlink->count_rxbytes(nread);
  				}
  			}
  		}
  
  		hrt_abstime t = hrt_absolute_time();
  
  		if (t - last_send_update > timeout * 1000) {
  			_mission_manager.check_active_mission();
  			_mission_manager.send(t);
  			_parameters_manager.send(t);
  			_mavlink_ftp.send(t);
  			_mavlink_log_handler.send(t);
  			last_send_update = t;
  		}
  
  	}
  
  	return nullptr;
  }
  
  void MavlinkReceiver::print_status()
  {
  
  }
  
  uint64_t MavlinkReceiver::sync_stamp(uint64_t usec)
  {
  
  	if (_time_offset != 0) {
  		return usec + (_time_offset / 1000) ;
  
  	} else {
  		return hrt_absolute_time();
  	}
  }
  
  
  void MavlinkReceiver::smooth_time_offset(int64_t offset_ns)
  {
  	/* The closer alpha is to 1.0, the faster the moving
  	 * average updates in response to new offset samples.
  	 */
  
  	_time_offset = (_time_offset_avg_alpha * offset_ns) + (1.0 - _time_offset_avg_alpha) * _time_offset;
  }
  
  
  void *MavlinkReceiver::start_helper(void *context)
  {
  
  	MavlinkReceiver *rcv = new MavlinkReceiver((Mavlink *)context);
  
  	if (!rcv) {
  		PX4_ERR("alloc failed");
  		return nullptr;
  	}
  
  	void *ret = rcv->receive_thread(nullptr);
  
  	delete rcv;
  
  	return ret;
  }
  
  void
  MavlinkReceiver::receive_start(pthread_t *thread, Mavlink *parent)
  {
  	pthread_attr_t receiveloop_attr;
  	pthread_attr_init(&receiveloop_attr);
  
  	struct sched_param param;
  	(void)pthread_attr_getschedparam(&receiveloop_attr, &param);
  	param.sched_priority = SCHED_PRIORITY_MAX - 80;
  	(void)pthread_attr_setschedparam(&receiveloop_attr, &param);
  
  	pthread_attr_setstacksize(&receiveloop_attr, PX4_STACK_ADJUSTED(2140));
  	pthread_create(thread, &receiveloop_attr, MavlinkReceiver::start_helper, (void *)parent);
  
  	pthread_attr_destroy(&receiveloop_attr);
  }
  