ROS Learning (III)-create a simple release node and subscription node, ros Node

ROS Learning (III)-create a simple release node and subscription node, ros Node

Summer vacation at home is a little slack, no, very slack--|! My conscience hurts and I want to make up the progress. But I suddenly find that I have been interrupted for a while, and I have forgotten some of the most basic symbols.

This time, we made a very basic task, restoring the previous progress.

 

1. Create a workspace

$ mkdir -p ~/catkin_xi/src$ cd ~/catkin_xi/src

The corresponding folder has been created in the home folder. Of course, there is nothing empty in it.

 

Then, use the catkin_make command to create a folder in the catkin workspace. The current directory should be able to see the 'build 'and 'devel' folders. In the 'devel 'folder, you can see several setup. sh files.

$ cd ~/catkin_xi/$ catkin_make

　　

 

Next, Run "source" and set the setup. sh file.

Switch the path to the src path,

$ cd ~/catkin_ws/src

　　

$ catkin_create_pkg beginner_tutorials std_msgs rospy roscpp

Use this command to create a new package named 'ininner _ tutorials ', which depends on std_msgs, roscpp, and rospy. Hosts file, both of which automatically contain information you provided when executing the catkin_create_pkg command.

Use the rospack command tool to view the first-level dependent package.

$ rospack depends1 beginner_tutorials

Of course, this may encounter a problem, that is, an error occurs. Enter this code to correct it.

$ source devel/setup.bash

　　

Rospack lists the dependent packages that are used as parameters when running the catkin_create_pkg command. These dependent packages are then stored in the package. xml file. Open this file and paste it in it,

<?xml version="1.0"?><package>... <buildtool_depend>catkin</buildtool_depend>  <build_depend>roscpp</build_depend>  <build_depend>rospy</build_depend>  <build_depend>std_msgs</build_depend>  <run_depend>roscpp</run_depend>  <run_depend>rospy</run_depend>  <run_depend>std_msgs</run_depend>...</package>

A package can also have several indirect dependent packages. Fortunately, using rospack can recursively detect all dependent packages.

Then, create a simple release node and subscription node.

$ roscd beginner_tutorials$ mkdir src$ touch src/talker.cpp

The same is true for creating subscription nodes.

$ cd beginner_tutorials$ touch src/listener.cpp