Getting Started with ROS Part 1: Nodes, Parameters and Topics

All robots based on ROS are programmed using five simple but core constructs, and you'll hear these often:
- Nodes
- Parameters
- Topics
- Services
- Actions
In this video we'll introduce Nodes, Parameters and Topics.

Commands used in this video:

Start turtlesim:
💻 ros2 run turtlesim turtlesim_node

Start the turtlesim keyboard controller:

💻 ros2 run turtlesim turtle_teleop_key

Start the turtlebot simulator:

Start the turtlebot keyboard controller:

💻 ros2 run turtlebot3_teleop teleop_keyboard

List the nodes in the ROS graph:

💻 ros2 node list

List the topics in the ROS graph:

💻 ros2 topic list

List the topics in the ROS graph along with the topic type:

💻 ros2 topic list -t

Echo raw data on a topic to the screen:

💻 ros2 topic echo /turtle1/cmd_vel

List the parameters in the ROS graph:

💻 ros2 param list

Find the value of a parameter:

💻 ros2 param get /turtlesim background_g

Set a parameter when starting turtlesim:

💻 ros2 run turtlesim turtlesim_node --ros-args -p background_r:=255

––––––––––––––––––––––––––––––
Soundtrack:
Creative Commons — Attribution-ShareAlike 3.0 Unported— CC BY-SA 3.0
Subscribe to Ubuntu on YouTube for more content like this:

And follow our other social accounts:

LinkedIn:
Twitter:
Facebook:
Instagram:

#linux #ubuntu #canonical #opensource

[SkyRiderJavelin]

Excellent introduction, clear & concise. You can always tell when someone knows what they are talking about when you get a clear image in your head of what's going on in your head

[pengfeiDu]

Are you running those graphic interface thing from a rpi? when I try the turtlesim example, it says "package turntlesim not found", thanks if anyone can help with my problem.

[dicktonyboy]

Another rabbit hole - offering so much promise. Thanks for this.