Nepu-Gear

1.- Workspace:

Create and build and empty workspace:

For the examples the workspace is called “catkin_ws”:

Create a package:

Go to the source directory of the workspace:

 cd ~/catkin_ws/src  

then create a package

 catkin_create_pkg [depend1] [depend2] [depend3]  

catkin_create_pkg requires that you give it a package_name and optionally a list of dependencies on which that package depends.

Example:

 catkin_create_pkg turtlebot_controller turtlesim geometry_msgs std_msgs roscpp rospy  

The name of the package is "turtlebot_controller" and the dependences are "turtlesim", "geometry_msgs", "std_msgs", "roscpp" and "rospy"

Build the packages in the catkin workspace: 

Go to main workspace directory: 

 cd ~/catkin_ws   

then build the packages: 

 catkin_make   

To add the workspace to the ROS environment : 

 . ~/catkin_ws/devel/setup.bash  

2.- Running and see states:

Start using ROS:

 roscore  

this command is the first thing you should run when using ROS.

Run a node of a package:

 rosrun [package_name] [node_name]  

Displays ROS nodes that are currently running:

 rosnode list  

/rosout is always present

Display more information about a node currently running:

 rosnode info [node]  

Example:

 rosnode info /rosout  

Displays ROS topics that are currently present:

 rostopic list  

See the actual messages that are being published on a topic:

 rostopic echo [topic]  

Get information about ROS topics:

 rostopic type [topic]  

It will be updated with more commands ...