Hovering (hello, world)

After completing Installation and Configuration, you are ready to test your setup for the first time!

First, run the test script in simulation mode to make sure your Python interpreter is set up correctly:

python hello_world.py --sim

In the 3D visualization, you should see a Crazyflie take off, hover for a few seconds, and then land.

If the script runs in simulation, you can move on to real hardware. First, start the crazyswarm_server:

source ros_ws/devel/setup.bash
roslaunch crazyswarm hover_swarm.launch

It should only take a few seconds to connect to the CFs. If you have the LED ring extension installed, you can see the connectivity by the color (green=good connectivity; red=bad connectivity). Furthermore, rviz will show the estimated pose of all CFs. If there is an error, such as a faulty configuration or a turned-off Crazyflie, an error message will be shown and the application exits. If there is a problem in the communication between the motion capture system and the Crazyswarm server, the application will not exit but the positions of the Crazyflies will not appear in rviz.

If crazyswarm_server is running correctly and you see CF pose(s) in rviz, open a new terminal (remember to source devel/setup.bash) and run the test script:

python hello_world.py

You should see the same behavior in real life. If you have more than one Crazyflie in your crazyflies.yaml, the script will select one arbitrarily.