px4主题的公告：orb advertise

orb_advert_t orb_advertise(const struct orb_metadata *meta, const void *data)

功能：公告发布者的主题；
说明：在发布主题之前是必须的；否则订阅者虽然能订阅，但是得不到数据；

int orb_publish(const struct orb_metadata *meta, orb_advert_t handle, const void *data)

功能：发布新数据到主题

int orb_subscribe(const struct orb_metadata *meta)

功能：订阅主题（topic）;
说明：即使订阅的主题没有被公告，但是也能订阅成功；但是在这种情况下，却得不到数据，直到主题被公告

(orb_advertise)
Topic(ORB_ID)

(orb_publish)

(orb_subscribe)

drivers/stm32/adc: system_power
adc.c
commander.cpp, meas_airspeed.cpp,

drivers/airspeed/airspeed.cpp: differential_pressure
ets_airspeed.cpp airspeed_calibration.cpp,

src/modules/sensors/sensors.cpp differential_pressure sensors.cpp
commander.cpp, sensors.cpp

drivers/airspeed/airspeed.cpp: subsystem_info
airspeed.cpp, commander.cpp

src/drivers/l140ls/l140ls.cpp subsystem_info
px4flow.cpp,

src/drivers/mbl2xx/mbl2xx.cpp subsystem_info trone.cpp

src/drivers/px4flow/px4flow.cpp subsystem_info l1401s.cpp, mb12xx.cpp

src/drivers/trone/trone.cpp subsystem_info

src/drivers/hil/hil.cpp actuator_outputs
ardrone_motor_control.c, fmu.cpp, hil.cpp,
mavlink_messages.cpp

ardrone_interface/ardrone_motor_control.c
actuator_outputs px4io.cpp

Attitude_estimator_ekf_main.cpp vehicle_attitude
attitude_estimator_ekf_main.cpp accelerometer_calibration.cpp

Attitude_estimator_q_main.cpp vehicle_attitude Attitude_estimator_ekf_main.cpp

Attitude_estimator_so3_main.cpp vehicle_attitude
Attitude_estimator_so3_main.cpp

ekf_att_pos_estimator_main.cpp vehicle_attitude
src/modules/controllib/uorb/blocks.cpp

mavlink_receiver.cpp vehicle_attitude
commander.cpp, flow_position_estimator_main.c

fw_att_control_main.cpp,
gimbal.cpp fw_pos_control_l1_main.cpp, mavlink_message.cpp

mc_att_control_main.cpp, mc_pos_control_main.cpp

multicopterLandDetector.cpp,

position_estimator_inav_main.c, vtol_att_control_main.cpp

fw_att_control_main.cpp vehicle_attitude_setpoint

fw_pos_control_l1_main.cpp vehicle_attitude_setpoint

mavlink_receiver.cpp vehicle_attitude_setpoint

mc_pos_control_main.cpp vehicle_attitude_setpoint

navigator_main.cpp vehicle_attitude_setpoint

src/modules/commander/commander.cpp vehicle_control_mode

src/modules/commander/commander.cpp vehicle_status

drivers/batt_smbus/batt_smbus.cpp batt_topic

drivers/bma180/bma180.cpp sensor_accel

mavlink_receiver.cpp sensor_accel

bottle_drop.cpp actuator_controls_2

src/drivers/gimbal/gimbal.cpp actuator_controls_2

fw_att_control_main.cpp _actuators_0_pub

fw_att_control_main.cpp _actuators_2_pub

src/example_hwtest/hwtest.c actuator_controls_0

mavlink_receiver.cpp actuator_controls_0

vtol_att_control_main.cpp
actuator_controls_0

src/modules/sensors/sensors.cpp actuator_controls_3

bottle_drop.cpp onboard_mission

src/modules/commander/commander.cpp home_position

src/modules/commander/commander.cpp actuator_armed

src/example_hwtest/hwtest.c actuator_armed

src/drivers/px4fmu/fmu.cpp actuator_armed

src/modules/commander/commander.cpp offboard_mission

mavlink_mission.cpp offboard_mission

ekf_att_pos_estimator_main.cpp estimator_status

ekf_att_pos_estimator_main.cpp wind_estimate

ekf_att_pos_estimator_main.cpp vehicle_local_position

flow_position_estimator_main.c vehicle_local_position

mavlink_receiver.cpp vehicle_local_position

position_esmator_inav_main.c vehicle_local_position

ekf_att_pos_estimator_main.cpp vehicle_global_position

mavlink_receiver.cpp vehicle_global_position

position_esmator_inav_main.c vehicle_global_position

src/modules/uvcan/actuators/esc.cpp esc_status

src/drivers/hott/message.cpp esc_status

src/drivers/mkblctrl/mkblctrl.cpp esc_status

flow_position_estimator_main.c filtered_bottom_flow

src/drivers/px4fmu/fmu.cpp input_rc

mavlink_receiver.cpp input_rc

src/drivers/px4io/px4io.cpp input_rc

fw_att_control_main.cpp rates_sp_id

mc_att_control_main.cpp _rates_sp_id

fw_pos_control_l1_main.cpp navigation_capabilities

fw_pos_control_l1_main.cpp tecs_status

src/modules/navigator/geofence.cpp fence

src/modules/uavcan/sensors/gnss.cpp vehicle_gps_position

src/drivers/gps/gps.cpp vehicle_gps_position

mavlink_receiver.cpp vehicle_gps_position

src/drivers/gps/gps.cpp satellite_info

src/drivers/hil/hil.cpp ORB_ID_VEHICLE_ATTITUDE_CONTROLS

src/examples/fixedwing_control/main.c ORB_ID_VEHICLE_ATTITUDE_CONTROLS

src/examples/rover_steering_control/main.cpp
ORB_ID_VEHICLE_ATTITUDE_CONTROLS

landDetector.cpp vehicle_land_detected

mavlink_receiver.cpp vehicle_land_detected

src/drivers/l140ls/l140ls.cpp sensor_range_finder

mavlink_receiver.cpp sensor_range_finder

src/drivers/mbl2xx/mbl2xx.cpp sensor_range_finder

src/drivers/sf0x/sf0x.cpp sensor_range_finder

src/drivers/trone/trone.cpp sensor_range_finder

mavlink_parameters.cpp rc_parameter_map

mavlink_receiver.cpp vehicle_command

src/modules/sdlog2/sdlog2.c vehicle_command

src/drivers/px4io/px4io.cpp vehicle_command

mavlink_receiver.cpp optical_flow

src/drivers/px4flow/px4flow.cpp optical_flow

mavlink_receiver.cpp vehicle_vicon_position

mavlink_receiver.cpp offboard_control_mode

mavlink_receiver.cpp vehicle_force_setpoint

mavlink_receiver.cpp position_setpoints_triplet

mavlink_receiver.cpp vision_position_estimate

mavlink_receiver.cpp vehicle_rates_setpoint

vtol_att_control_main.cpp
vehicle_rates_setpoint

mavlink_receiver.cpp manual_control_setpoints

src/modules/sensors/sensors.cpp manual_control_setpoint

mavlink_receiver.cpp time_offset

mavlink_receiver.cpp airspeed

src/modules/sdlog2/sdlog2.c airspeed

mavlink_receiver.cpp sensor_gyro

mavlink_receiver.cpp sensor_mag

mavlink_receiver.cpp sensor_baro

mavlink_receiver.cpp sensor_combined

src/modules/sensors/sensors.cpp sensor_combined

src/drivers/px4io/px4io.cpp battery_status

mavlink_receiver.cpp battery_status

src/modules/sensors/sensors.cpp battery_status

mc_att_control_main.cpp ma_att_ctrl_status

mc_pos_control_main.cpp vehicle_global_velocity_setpoint

mc_pos_control_main.cpp vehicle_local_position_setpoint

src/systemcmds/motor_test/motor_test.c test_motor

navigator_main.cpp position_setpoint_triplet

navigator_main.cpp mission_result

navigator_main.cpp geofence_result

src/modules/systemlib/param/param.c parameter_update

src/drivers/px4io/px4io.cpp safety

src/drivers/px4io/px4io.cpp servorail_status

src/drivers/px4io/px4io.cpp multirotor_motor_limits

src/modules/sensors/sensors.cpp rc_channels

src/modules/uorb/uorb.cpp orb_test

vtol_att_control_main.cpp vtol_vehicle_status