fix(mavlink): Allowing custom modes to request offboard setpoints via the external mode registration

msg/px4_msgs_old/msg/RegisterExtComponentRequestV1.msg

@@ -0,0 +1,24 @@
+# Request to register an external component
+
+uint32 MESSAGE_VERSION = 1
+
+uint64 timestamp # time since system start (microseconds)
+
+uint64 request_id                  # ID, set this to a random value
+char[25] name                      # either the requested mode name, or component name
+
+uint16 LATEST_PX4_ROS2_API_VERSION = 1 # API version compatibility. Increase this on a breaking semantic change. Changes to any message field are detected separately and do not require an API version change.
+
+uint16 px4_ros2_api_version   # Set to LATEST_PX4_ROS2_API_VERSION
+
+# Components to be registered
+bool register_arming_check
+bool register_mode                 # registering a mode also requires arming_check to be set
+bool register_mode_executor        # registering an executor also requires a mode to be registered (which is the owned mode by the executor)
+
+bool enable_replace_internal_mode  # set to true if an internal mode should be replaced
+uint8 replace_internal_mode        # vehicle_status::NAVIGATION_STATE_*
+bool activate_mode_immediately     # switch to the registered mode (can only be set in combination with an executor)
+bool not_user_selectable           # mode cannot be selected by the user
+
+uint8 ORB_QUEUE_LENGTH = 2

msg/px4_msgs_old/msg/VehicleStatusV3.msg

@@ -0,0 +1,123 @@
+# Encodes the system state of the vehicle published by commander
+
+uint32 MESSAGE_VERSION = 3
+
+uint64 timestamp # time since system start (microseconds)
+
+uint64 armed_time # Arming timestamp (microseconds)
+uint64 takeoff_time # Takeoff timestamp (microseconds)
+
+uint8 arming_state
+uint8 ARMING_STATE_DISARMED = 1
+uint8 ARMING_STATE_ARMED    = 2
+
+uint8 latest_arming_reason
+uint8 latest_disarming_reason
+uint8 ARM_DISARM_REASON_STICK_GESTURE = 1
+uint8 ARM_DISARM_REASON_RC_SWITCH = 2
+uint8 ARM_DISARM_REASON_COMMAND_INTERNAL = 3
+uint8 ARM_DISARM_REASON_COMMAND_EXTERNAL = 4
+uint8 ARM_DISARM_REASON_MISSION_START = 5
+uint8 ARM_DISARM_REASON_LANDING = 6
+uint8 ARM_DISARM_REASON_PREFLIGHT_INACTION = 7
+uint8 ARM_DISARM_REASON_KILL_SWITCH = 8
+uint8 ARM_DISARM_REASON_RC_BUTTON = 13
+uint8 ARM_DISARM_REASON_FAILSAFE = 14
+
+uint64 nav_state_timestamp # time when current nav_state activated
+
+uint8 nav_state_user_intention                  # Mode that the user selected (might be different from nav_state in a failsafe situation)
+
+uint8 nav_state                                 # Currently active mode
+uint8 NAVIGATION_STATE_MANUAL = 0               # Manual mode
+uint8 NAVIGATION_STATE_ALTCTL = 1               # Altitude control mode
+uint8 NAVIGATION_STATE_POSCTL = 2               # Position control mode
+uint8 NAVIGATION_STATE_AUTO_MISSION = 3         # Auto mission mode
+uint8 NAVIGATION_STATE_AUTO_LOITER = 4          # Auto loiter mode
+uint8 NAVIGATION_STATE_AUTO_RTL = 5             # Auto return to launch mode
+uint8 NAVIGATION_STATE_POSITION_SLOW = 6
+uint8 NAVIGATION_STATE_FREE5 = 7
+uint8 NAVIGATION_STATE_ALTITUDE_CRUISE = 8      # Altitude with Cruise mode
+uint8 NAVIGATION_STATE_FREE3 = 9
+uint8 NAVIGATION_STATE_ACRO = 10                # Acro mode
+uint8 NAVIGATION_STATE_FREE2 = 11
+uint8 NAVIGATION_STATE_DESCEND = 12             # Descend mode (no position control)
+uint8 NAVIGATION_STATE_TERMINATION = 13         # Termination mode
+uint8 NAVIGATION_STATE_OFFBOARD = 14
+uint8 NAVIGATION_STATE_STAB = 15                # Stabilized mode
+uint8 NAVIGATION_STATE_FREE1 = 16
+uint8 NAVIGATION_STATE_AUTO_TAKEOFF = 17        # Takeoff
+uint8 NAVIGATION_STATE_AUTO_LAND = 18           # Land
+uint8 NAVIGATION_STATE_AUTO_FOLLOW_TARGET = 19  # Auto Follow
+uint8 NAVIGATION_STATE_AUTO_PRECLAND = 20       # Precision land with landing target
+uint8 NAVIGATION_STATE_ORBIT = 21               # Orbit in a circle
+uint8 NAVIGATION_STATE_AUTO_VTOL_TAKEOFF = 22   # Takeoff, transition, establish loiter
+uint8 NAVIGATION_STATE_EXTERNAL1 = 23
+uint8 NAVIGATION_STATE_EXTERNAL2 = 24
+uint8 NAVIGATION_STATE_EXTERNAL3 = 25
+uint8 NAVIGATION_STATE_EXTERNAL4 = 26
+uint8 NAVIGATION_STATE_EXTERNAL5 = 27
+uint8 NAVIGATION_STATE_EXTERNAL6 = 28
+uint8 NAVIGATION_STATE_EXTERNAL7 = 29
+uint8 NAVIGATION_STATE_EXTERNAL8 = 30
+uint8 NAVIGATION_STATE_MAX = 31
+
+uint8 executor_in_charge                        # Current mode executor in charge (0=Autopilot)
+uint8 nav_state_display                         # User-visible nav state sent via MAVLink (executor state if active, otherwise nav_state)
+
+uint32 valid_nav_states_mask                    # Bitmask for all valid nav_state values
+uint32 can_set_nav_states_mask                  # Bitmask for all modes that a user can select
+
+uint8 hil_state
+uint8 HIL_STATE_OFF = 0
+uint8 HIL_STATE_ON = 1
+
+# Current vehicle locomotion method. A vehicle can have different methods (e.g. VTOL transitions from RW to FW method)
+uint8 vehicle_type
+uint8 VEHICLE_TYPE_UNSPECIFIED = 0
+uint8 VEHICLE_TYPE_ROTARY_WING = 1
+uint8 VEHICLE_TYPE_FIXED_WING = 2
+uint8 VEHICLE_TYPE_ROVER = 3
+
+uint8 FAILSAFE_DEFER_STATE_DISABLED = 0
+uint8 FAILSAFE_DEFER_STATE_ENABLED = 1
+uint8 FAILSAFE_DEFER_STATE_WOULD_FAILSAFE = 2 # Failsafes deferred, but would trigger a failsafe
+
+bool failsafe # true if system is in failsafe state (e.g.:RTL, Hover, Terminate, ...)
+bool failsafe_and_user_took_over # true if system is in failsafe state but the user took over control
+uint8 failsafe_defer_state # one of FAILSAFE_DEFER_STATE_*
+
+# Link loss
+bool gcs_connection_lost              # datalink to GCS lost
+uint8 gcs_connection_lost_counter     # counts unique GCS connection lost events
+bool high_latency_data_link_lost # Set to true if the high latency data link (eg. RockBlock Iridium 9603 telemetry module) is lost
+
+# VTOL flags
+bool is_vtol             # True if the system is VTOL capable
+bool is_vtol_tailsitter  # True if the system performs a 90° pitch down rotation during transition from MC to FW
+bool in_transition_mode  # True if VTOL is doing a transition
+bool in_transition_to_fw # True if VTOL is doing a transition from MC to FW
+
+# MAVLink identification
+uint8 system_type  # system type, contains mavlink MAV_TYPE
+uint8 system_id	   # system id, contains MAVLink's system ID field
+uint8 component_id # subsystem / component id, contains MAVLink's component ID field
+
+bool safety_button_available # Set to true if a safety button is connected
+bool safety_off # Set to true if safety is off
+
+bool power_input_valid                            # set if input power is valid
+bool usb_connected                                # set to true (never cleared) once telemetry received from usb link
+
+bool open_drone_id_system_present
+bool open_drone_id_system_healthy
+
+bool parachute_system_present
+bool parachute_system_healthy
+
+bool traffic_avoidance_system_present
+
+bool rc_calibration_in_progress
+bool calibration_enabled
+
+bool pre_flight_checks_pass		# true if all checks necessary to arm pass

msg/translation_node/translations/all_translations.h

@@ -16,9 +16,11 @@
 #include "translation_home_position_v1.h"
 #include "translation_register_ext_component_reply_v1.h"
 #include "translation_register_ext_component_request_v1.h"
+#include "translation_register_ext_component_request_v2.h"
 #include "translation_vehicle_attitude_setpoint_v1.h"
 #include "translation_vehicle_command_ack_v1.h"
 #include "translation_vehicle_local_position_v1.h"
 #include "translation_vehicle_status_v1.h"
 #include "translation_vehicle_status_v2.h"
 #include "translation_vehicle_status_v3.h"
+#include "translation_vehicle_status_v4.h"

msg/translation_node/translations/translation_register_ext_component_request_v1.h

@@ -6,14 +6,14 @@
 
 // Translate RegisterExtComponentRequest v0 <--> v1
 #include <px4_msgs_old/msg/register_ext_component_request_v0.hpp>
-#include <px4_msgs/msg/register_ext_component_request.hpp>
+#include <px4_msgs_old/msg/register_ext_component_request_v1.hpp>
 
 class RegisterExtComponentRequestV1Translation {
 public:
     using MessageOlder = px4_msgs_old::msg::RegisterExtComponentRequestV0;
     static_assert(MessageOlder::MESSAGE_VERSION == 0);
 
-    using MessageNewer = px4_msgs::msg::RegisterExtComponentRequest;
+    using MessageNewer = px4_msgs_old::msg::RegisterExtComponentRequestV1;
     static_assert(MessageNewer::MESSAGE_VERSION == 1);
 
     static constexpr const char* kTopic = "fmu/in/register_ext_component_request";

msg/translation_node/translations/translation_register_ext_component_request_v2.h

@@ -0,0 +1,51 @@
+/****************************************************************************
+ * Copyright (c) 2026 PX4 Development Team.
+ * SPDX-License-Identifier: BSD-3-Clause
+ ****************************************************************************/
+#pragma once
+
+// Translate RegisterExtComponentRequest v1 <--> v2
+#include <px4_msgs_old/msg/register_ext_component_request_v1.hpp>
+#include <px4_msgs/msg/register_ext_component_request.hpp>
+
+class RegisterExtComponentRequestV2Translation {
+public:
+    using MessageOlder = px4_msgs_old::msg::RegisterExtComponentRequestV1;
+    static_assert(MessageOlder::MESSAGE_VERSION == 1);
+
+    using MessageNewer = px4_msgs::msg::RegisterExtComponentRequest;
+    static_assert(MessageNewer::MESSAGE_VERSION == 2);
+
+    static constexpr const char* kTopic = "fmu/in/register_ext_component_request";
+
+    static void fromOlder(const MessageOlder &msg_older, MessageNewer &msg_newer) {
+	    msg_newer.timestamp = msg_older.timestamp;
+	    msg_newer.request_id = msg_older.request_id;
+	    msg_newer.name = msg_older.name;
+	    msg_newer.px4_ros2_api_version = msg_older.px4_ros2_api_version;
+	    msg_newer.register_arming_check = msg_older.register_arming_check;
+	    msg_newer.register_mode = msg_older.register_mode;
+	    msg_newer.register_mode_executor = msg_older.register_mode_executor;
+	    msg_newer.enable_replace_internal_mode = msg_older.enable_replace_internal_mode;
+	    msg_newer.replace_internal_mode = msg_older.replace_internal_mode;
+	    msg_newer.activate_mode_immediately = msg_older.activate_mode_immediately;
+	    msg_newer.not_user_selectable = msg_older.not_user_selectable;
+	    msg_newer.request_offboard_setpoints = false;
+    }
+
+    static void toOlder(const MessageNewer &msg_newer, MessageOlder &msg_older) {
+	    msg_older.timestamp = msg_newer.timestamp;
+	    msg_older.request_id = msg_newer.request_id;
+	    msg_older.name = msg_newer.name;
+	    msg_older.px4_ros2_api_version = msg_newer.px4_ros2_api_version;
+	    msg_older.register_arming_check = msg_newer.register_arming_check;
+	    msg_older.register_mode = msg_newer.register_mode;
+	    msg_older.register_mode_executor = msg_newer.register_mode_executor;
+	    msg_older.enable_replace_internal_mode = msg_newer.enable_replace_internal_mode;
+	    msg_older.replace_internal_mode = msg_newer.replace_internal_mode;
+	    msg_older.activate_mode_immediately = msg_newer.activate_mode_immediately;
+	    msg_older.not_user_selectable = msg_newer.not_user_selectable;
+    }
+};
+
+REGISTER_TOPIC_TRANSLATION_DIRECT(RegisterExtComponentRequestV2Translation);

msg/translation_node/translations/translation_vehicle_status_v3.h

@@ -6,14 +6,14 @@
 
 // Translate VehicleStatus v2 <--> v3
 #include <px4_msgs_old/msg/vehicle_status_v2.hpp>
-#include <px4_msgs/msg/vehicle_status.hpp>
+#include <px4_msgs_old/msg/vehicle_status_v3.hpp>
 
 class VehicleStatusV3Translation {
 public:
 	using MessageOlder = px4_msgs_old::msg::VehicleStatusV2;
 	static_assert(MessageOlder::MESSAGE_VERSION == 2);
 
-	using MessageNewer = px4_msgs::msg::VehicleStatus;
+	using MessageNewer = px4_msgs_old::msg::VehicleStatusV3;
 	static_assert(MessageNewer::MESSAGE_VERSION == 3);
 
 	static constexpr const char* kTopic = "fmu/out/vehicle_status";

msg/translation_node/translations/translation_vehicle_status_v4.h

@@ -0,0 +1,109 @@
+/****************************************************************************
+ * Copyright (c) 2026 PX4 Development Team.
+ * SPDX-License-Identifier: BSD-3-Clause
+ ****************************************************************************/
+#pragma once
+
+// Translate VehicleStatus v3 <--> v4
+#include <px4_msgs_old/msg/vehicle_status_v3.hpp>
+#include <px4_msgs/msg/vehicle_status.hpp>
+
+class VehicleStatusV4Translation {
+public:
+	using MessageOlder = px4_msgs_old::msg::VehicleStatusV3;
+	static_assert(MessageOlder::MESSAGE_VERSION == 3);
+
+	using MessageNewer = px4_msgs::msg::VehicleStatus;
+	static_assert(MessageNewer::MESSAGE_VERSION == 4);
+
+	static constexpr const char* kTopic = "fmu/out/vehicle_status";
+
+	static void fromOlder(const MessageOlder &msg_older, MessageNewer &msg_newer) {
+		msg_newer.timestamp = msg_older.timestamp;
+		msg_newer.armed_time = msg_older.armed_time;
+		msg_newer.takeoff_time = msg_older.takeoff_time;
+		msg_newer.arming_state = msg_older.arming_state;
+		msg_newer.latest_arming_reason = msg_older.latest_arming_reason;
+		msg_newer.latest_disarming_reason = msg_older.latest_disarming_reason;
+		msg_newer.nav_state_timestamp = msg_older.nav_state_timestamp;
+		msg_newer.nav_state_user_intention = msg_older.nav_state_user_intention;
+		msg_newer.nav_state = msg_older.nav_state;
+		msg_newer.executor_in_charge = msg_older.executor_in_charge;
+		msg_newer.nav_state_display = msg_older.nav_state_display;
+		msg_newer.accepts_offboard_setpoints = false;
+		msg_newer.valid_nav_states_mask = msg_older.valid_nav_states_mask;
+		msg_newer.can_set_nav_states_mask = msg_older.can_set_nav_states_mask;
+		msg_newer.hil_state = msg_older.hil_state;
+		msg_newer.vehicle_type = msg_older.vehicle_type;
+		msg_newer.failsafe = msg_older.failsafe;
+		msg_newer.failsafe_and_user_took_over = msg_older.failsafe_and_user_took_over;
+		msg_newer.failsafe_defer_state = msg_older.failsafe_defer_state;
+		msg_newer.gcs_connection_lost = msg_older.gcs_connection_lost;
+		msg_newer.gcs_connection_lost_counter = msg_older.gcs_connection_lost_counter;
+		msg_newer.high_latency_data_link_lost = msg_older.high_latency_data_link_lost;
+		msg_newer.is_vtol = msg_older.is_vtol;
+		msg_newer.is_vtol_tailsitter = msg_older.is_vtol_tailsitter;
+		msg_newer.in_transition_mode = msg_older.in_transition_mode;
+		msg_newer.in_transition_to_fw = msg_older.in_transition_to_fw;
+		msg_newer.system_type = msg_older.system_type;
+		msg_newer.system_id = msg_older.system_id;
+		msg_newer.component_id = msg_older.component_id;
+		msg_newer.safety_button_available = msg_older.safety_button_available;
+		msg_newer.safety_off = msg_older.safety_off;
+		msg_newer.power_input_valid = msg_older.power_input_valid;
+		msg_newer.usb_connected = msg_older.usb_connected;
+		msg_newer.open_drone_id_system_present = msg_older.open_drone_id_system_present;
+		msg_newer.open_drone_id_system_healthy = msg_older.open_drone_id_system_healthy;
+		msg_newer.parachute_system_present = msg_older.parachute_system_present;
+		msg_newer.parachute_system_healthy = msg_older.parachute_system_healthy;
+		msg_newer.traffic_avoidance_system_present = msg_older.traffic_avoidance_system_present;
+		msg_newer.rc_calibration_in_progress = msg_older.rc_calibration_in_progress;
+		msg_newer.calibration_enabled = msg_older.calibration_enabled;
+		msg_newer.pre_flight_checks_pass = msg_older.pre_flight_checks_pass;
+	}
+
+	static void toOlder(const MessageNewer &msg_newer, MessageOlder &msg_older) {
+		msg_older.timestamp = msg_newer.timestamp;
+		msg_older.armed_time = msg_newer.armed_time;
+		msg_older.takeoff_time = msg_newer.takeoff_time;
+		msg_older.arming_state = msg_newer.arming_state;
+		msg_older.latest_arming_reason = msg_newer.latest_arming_reason;
+		msg_older.latest_disarming_reason = msg_newer.latest_disarming_reason;
+		msg_older.nav_state_timestamp = msg_newer.nav_state_timestamp;
+		msg_older.nav_state_user_intention = msg_newer.nav_state_user_intention;
+		msg_older.nav_state = msg_newer.nav_state;
+		msg_older.executor_in_charge = msg_newer.executor_in_charge;
+		msg_older.nav_state_display = msg_newer.nav_state_display;
+		msg_older.valid_nav_states_mask = msg_newer.valid_nav_states_mask;
+		msg_older.can_set_nav_states_mask = msg_newer.can_set_nav_states_mask;
+		msg_older.hil_state = msg_newer.hil_state;
+		msg_older.vehicle_type = msg_newer.vehicle_type;
+		msg_older.failsafe = msg_newer.failsafe;
+		msg_older.failsafe_and_user_took_over = msg_newer.failsafe_and_user_took_over;
+		msg_older.failsafe_defer_state = msg_newer.failsafe_defer_state;
+		msg_older.gcs_connection_lost = msg_newer.gcs_connection_lost;
+		msg_older.gcs_connection_lost_counter = msg_newer.gcs_connection_lost_counter;
+		msg_older.high_latency_data_link_lost = msg_newer.high_latency_data_link_lost;
+		msg_older.is_vtol = msg_newer.is_vtol;
+		msg_older.is_vtol_tailsitter = msg_newer.is_vtol_tailsitter;
+		msg_older.in_transition_mode = msg_newer.in_transition_mode;
+		msg_older.in_transition_to_fw = msg_newer.in_transition_to_fw;
+		msg_older.system_type = msg_newer.system_type;
+		msg_older.system_id = msg_newer.system_id;
+		msg_older.component_id = msg_newer.component_id;
+		msg_older.safety_button_available = msg_newer.safety_button_available;
+		msg_older.safety_off = msg_newer.safety_off;
+		msg_older.power_input_valid = msg_newer.power_input_valid;
+		msg_older.usb_connected = msg_newer.usb_connected;
+		msg_older.open_drone_id_system_present = msg_newer.open_drone_id_system_present;
+		msg_older.open_drone_id_system_healthy = msg_newer.open_drone_id_system_healthy;
+		msg_older.parachute_system_present = msg_newer.parachute_system_present;
+		msg_older.parachute_system_healthy = msg_newer.parachute_system_healthy;
+		msg_older.traffic_avoidance_system_present = msg_newer.traffic_avoidance_system_present;
+		msg_older.rc_calibration_in_progress = msg_newer.rc_calibration_in_progress;
+		msg_older.calibration_enabled = msg_newer.calibration_enabled;
+		msg_older.pre_flight_checks_pass = msg_newer.pre_flight_checks_pass;
+	}
+};
+
+REGISTER_TOPIC_TRANSLATION_DIRECT(VehicleStatusV4Translation);

msg/versioned/RegisterExtComponentRequest.msg

@@ -1,6 +1,6 @@
 # Request to register an external component
 
-uint32 MESSAGE_VERSION = 1
+uint32 MESSAGE_VERSION = 2
 
 uint64 timestamp # time since system start (microseconds)
 
@@ -20,5 +20,6 @@ bool enable_replace_internal_mode  # set to true if an internal mode should be r
 uint8 replace_internal_mode        # vehicle_status::NAVIGATION_STATE_*
 bool activate_mode_immediately     # switch to the registered mode (can only be set in combination with an executor)
 bool not_user_selectable           # mode cannot be selected by the user
+bool request_offboard_setpoints    # set to true if the registered mode wants to receive offboard trajectory setpoints via MAVLink
 
 uint8 ORB_QUEUE_LENGTH = 2

msg/versioned/VehicleStatus.msg

@@ -1,6 +1,6 @@
 # Encodes the system state of the vehicle published by commander
 
-uint32 MESSAGE_VERSION = 3
+uint32 MESSAGE_VERSION = 4
 
 uint64 timestamp # time since system start (microseconds)
 
@@ -65,6 +65,8 @@ uint8 NAVIGATION_STATE_MAX = 31
 uint8 executor_in_charge                        # Current mode executor in charge (0=Autopilot)
 uint8 nav_state_display                         # User-visible nav state sent via MAVLink (executor state if active, otherwise nav_state)
 
+bool accepts_offboard_setpoints                 # True if the current mode accepts offboard trajectory setpoints via MAVLink
+
 uint32 valid_nav_states_mask                    # Bitmask for all valid nav_state values
 uint32 can_set_nav_states_mask                  # Bitmask for all modes that a user can select
 

src/modules/commander/Commander.cpp

@@ -2025,6 +2025,7 @@ void Commander::run()
 
 			// vehicle_status publish (after prearm/preflight updates above)
 			_mode_management.getModeStatus(_vehicle_status.valid_nav_states_mask, _vehicle_status.can_set_nav_states_mask);
+			_vehicle_status.accepts_offboard_setpoints = _mode_management.currentModeAcceptsOffboardSetpoints(_vehicle_status.nav_state);
 			_vehicle_status.timestamp = hrt_absolute_time();
 			_vehicle_status_pub.publish(_vehicle_status);