ROS Programming: Building Powerful Robots

How does joy_node send joystick movements?

With the joy_node package active, we are going to see the messages sent by this node. This will help us understand how it sends information about axes and buttons.

To see the messages sent by the node, we can use this command:

    $ rostopic echo /joy  

And then, we can see each message sent as follows:

You will see two main vectors: one for axes and the other for buttons. Obviously, these vectors are used to publish the states of the buttons and axes of the real hardware.

If you want to know the message type, type the following command line in a shell:

    $ rostopic type /joy  

You will then obtain the ...