Getting started

Make sure to have the installation done before starting with this guide.

Configuration

Start by configuring the hardware as well as the software components.

Note

If you only want to use the simulation, you can skip this section and skip to Usage section immediately.

Hardware

If you want to use real hardware, you need to configure your Crazyradio, Crazyflies (and motion capture system).

• Crazyradio
• Crazyflie

Software

Lastly you need to configure the software. This includes setting up the motion capture system, as well as the Crazyflie configuration.

• Crazyflie Configuration
• Setting up Motion Capture
• Different Implementations

Additional Configuration:

• Rviz2 Configuration

Usage

The crazyflies package provides a convenient launch file (framework.launch.py) which allows you to launch with hardware, webots or mixed crazyflies.

1. Sourcing (needs to be done in every new terminal):

   source install/setup.bash
   

2. Launch the framework with:

   ros2 launch crazyflies framework.launch.py backend:=webots
   

   Select hardware, webots, or both as your backend.

   When hardware or both is selected it is necessary to set the radio_channels argument (it defaults to 80):

   ros2 launch crazyflies framework.launch.py radio_channels:=[100] backend:=hardware
   

3. Starting with webots or both will not automatically open Webots. You need to open Webots seperately and select the provided world (see Installation). (The Framework will then connect as extern controller to the Webots simulation).

4. Now it is time to connect your first crazyflie. To simplify this process ds-crazyflies provides two panels for RQT.

   • For this RQT first needs to discover these plugins, for this run the following command in a new terminal (in the ds-crazyflies folder):

   source install/setup.bash
   rqt --force-discover
   

   

   You should now find two new plugins in the RQT plugin list. Add both Plugins to your View.

   Note

   When inside VSCode unset GTK_PATH needs to be run before starting RQT, otherwise it will not start.

   • The Add Plugin can then be used to connnect the crazyflie.

     Choose the correct backend and provide the necessary parameters. (For the basic webots-world the id is 0).

     

   • The connected crazyflies are now listed in the Crazyflie List plugin.

     From here you can monitor the battery voltage and connection status of each crazyflie. For the webots crazyflie most values do not update. When a crazyflie disconnects it will be greyed out.

     

     The small control button between the LinkQuality and the PropellerTest button opens a small high level commander interface.

     Here you can send takeoff, goTo and land commands to the crazyflie. The position field should also update correctly.

Usage without RQT

The RQT-Plugins are just convenient buttons for service calls and topic publications. You can also connect a crazyflie by calling the appropriate service directly.

1. For connecting a hardware crazyflie:

   ros2 service call /crazyflie_hardware_gateway/add_crazyflie crazyflie_hardware_gateway/srv/AddCrazyflie "id: 0
       channel: 100
       initial_position: [0.0, 0.0, 0.0]
       type: 'default'"
   

   For connecting a webots crazyflie:

   ros2 service call /crazyflie_webots_gateway/add_crazyflie crazyflie_webots_gateway_interfaces/srv/WebotsCrazyflie "id: 0"
   

   The result should include a success=True.

2. When the crazyflie is connected, you can use the high level commander to control the crazyflie:

   Note

   Do not forget the ‘–once’ flag to only send the command once.

   • Takeoff

     ros2 topic pub /cf0/takeoff crazyflie_interfaces/msg/Takeoff "group_mask: 0
         height: 0.5
         yaw: 0.0
         use_current_yaw: false
         duration: 2.0" --once
     

   • goTo

     ros2 topic pub /cf0/go_to crazyflie_interfaces/msg/GoTo "group_mask: 0
         relative: true
         linear: false
         goal: [1.0, 0.0, 0.5] # TODO
         yaw: 0.0
         duration: 2.0" --once
     

   • Land

     ros2 topic pub /cf0/land crazyflie_interfaces/msg/Land "group_mask: 0
         height: 0.0
         yaw: 0.0
         use_current_yaw: false
         duration: 2.0" --once
     

Note

Creating a Crazyflie/Safeflie will automatically set it up to be tracked by a motion capture system, but this is subject to change. If you instantiate a Crazyflie using the gateway (see Usage /Architecture), then you may provide a type field.

Start implementing your application logic by following the API Documentation.