Operation - Software Tools
Operation - Software Tools#
This section describes how to use available software tools for your Duckiebot including the
start_gui_tools interface, ROS tools, and the
no-vnc Desktop interface.
If you are familiar with how ROS works and like using the command line interface, you can run:
dts start_gui_tools ![DUCKIEBOT_NAME]
to obtain a terminal (container actually) that is connected to the Duckiebot ROS network. In this terminal you can perform all ROS commands and have access to all ROS messages streaming on your Duckiebot.
Note again that in these commands you input the Duckiebot
hostname; do not include
You can only start one instance of the
start_gui_tools container. If you want multiple terminal instances, it is recommended to use
If you would rather use an image that runs
no-vnc to provide you with a Desktop environment connected to the Duckiebot, type:
dts start_gui_tools --vnc ![DUCKIEBOT_NAME]
no-vnc, use your browser and navigate to:
You can treat this environment as a typical Ubuntu machine with ROS installed and configured to talk with your Duckiebot. Click on the
Terminal Desktop icon to open the command line interface.
Using the ROS utilities#
Once you’ve opened a terminal connected to the Duckiebot container using one of the two methods above, you can use any of the commands below within that interface to check the data streams in ROS.
You can see a list of published topics with the command:
See also: For more information about
rostopic, see the official ROS wiki here.
You should see at least the following topics:
/![DUCKIEBOT_NAME]/camera_node/camera_info /![DUCKIEBOT_NAME]/camera_node/image/compressed /rosout /rosout_agg
There might be other topics if you have already started other demos.
Show topics frequency#
You can use
rostopic hz to see the statistics about the publishing frequency:
rostopic hz /![DUCKIEBOT_NAME]/camera_node/image/compressed
On a Raspberry Pi 3, you should see a number close to 30 Hz:
average rate: 30.016 min: 0.026s max: 0.045s std dev: 0.00190s window: 841
Use Ctrl-C to stop
Show topics data#
You can view the messages in real time with the command
rostopic echo /![DUCKIEBOT_NAME]/camera_node/image/compressed
You should see a large sequence of numbers being printed to your terminal.
That’s the “image” - as seen by a machine.
To see what your Duckiebot sees, you can run
The command will open a window where you can view the image.
You will have to select the
camera_node/image/compressed topic from the drop-down menu:
Or if you are using the
no-vnc interface, click on the
RQT Image View application icon on the desktop. You will see the same
rqt_image_view interface start up
If you want to explore the relationship between all the nodes, topics and tf, you can open up a terminal and run:
This will open up a window that contains all the ROS topics being published, all the ROS nodes running, and it is a very handy tool to understand the relationship between nodes.
My ros commands are not working. I cannot use tab to auto complete ROS commands.
You can fix that by sourcing
I cannot connect to ROS master.
Go to Dashboard > Portainer to make sure the following containers are running without errors:
If they are not running, refer to Docker troubleshooting for instructions to resolve the issue.