How To

This page shows short how to’s for the advanced usage.

Tracking Non-Robotic Objects

In some cases it can be useful to provide the position or pose of rigid bodies in the motion capture space to the robots. For example, consider a collision avoidance algorithms implemented on-board the firmware that requires to know the position of an obstacle. In that case, a “virtual” robot can be defined in crazyflies.yaml

        enabled: true
        initial_position: [0, -0.5, 0]
        type: marker  # see robot_types
        id: 255

    # Just a marker to track, not a robot to connect to
        connection: none
            enabled: true
            marker: default_single_marker
            dynamics: default

Here, the position of the obstacle will be tracked using the motion_capture_tracking ROS package. The resulting pose will be available via TF (named “obstacle”) and send to the firmware of the actual robots with id 255.


If there is a crash (e.g., segmentation fault) in the crazyflie_server (C++ backend), you can find the stacktrace by using gdb. First, compile your code in debug mode, then run the launch file with the debug flag, which will open an xterm window. If you don’t have xterm installed, you can do so using sudo apt install xterm.

colcon build --symlink-install --cmake-args -DCMAKE_BUILD_TYPE=Debug
ros2 launch crazyflie debug:=True