system_monitor_ros is a ROS 2 package to publish onboard companion status messages to the flight controller through px4_ros_com micro-RTPS bridge. Similarly, this is a reference implementation of the Mavlink message ONBOARD_COMPUTER_STATUS, but following the message definition of the uORB message onboard_computer_status, which ROS counter-part is defined in px4_msgs. This same message is published by this node in the /fmu/onboard_computer_status/in topic.

• ROS 2 Dashing or Eloquent - follow the install guide;
• Colcon build tool: apt install python3-colcon-common-extensions
• px4_ros_com built on the same workspace or on a different workspace that can be overlayed;
• px4_msgs built on the same workspace or on a different workspace that can be overlayed;

If px4_ros_com and px4_msgs were not built on another workspace, they can be built together with this package using the build_ros2_workspace.bash script for that purpose:

    $ mkdir -p colcon_ws/src
    $ cd colcon_ws/src
    $ git clone https://github.com/Auterion/system_monitor_ros.git -b ros2
    $ git clone https://github.com/PX4/px4_ros_com.git
    $ git clone https://github.com/PX4/px4_msgs.git
    $ ./px4_ros_com/scripts/build_ros2_workspace.bash

    $ source colcon_ws/install/setup.bash

The monitor can be run by the following ros2 launch command. The parameters can be edited in the monitor_parameters.yaml file.

    $ ros2 launch system_monitor_ros system_monitor.launch.py

To communicate with the autopilot, make sure that the micrortps_agent of px4_ros_com and the micrortps_client on the autopilot are both running.