[ROS In 5 Minutes] 003 - How to create a ROS Publisher

Hi all!

Welcome to this "ROS In 5 Minutes" videos series.

In today's videos we are going to see how to create a ROS Publisher.

But before we start, if you want to Learn ROS Fast, we recommend you the following courses:

ROS In 5 Days (Python) - http://www.theconstructsim.com/construct-learn-develop-robots-using-ros/robotigniteacademy_learnros/ros-courses-library/ros-basics-in-5-days/
ROS In 5 Days (C++) - http://www.theconstructsim.com/construct-learn-develop-robots-using-ros/robotigniteacademy_learnros/ros-courses-library/ros-courses-ros-basics-in-5-days-c/

We have a POST that contains the content of this video: on http://www.theconstructsim.com/ros-5-minutes-003-create-ros-publisher/, but if you want a summary, we have it here too.

Regarding to the creation of the ROS Publisher, the commands used on the video to create a package named "tutorial" which depends on the "rospy" package were the following:

cd catkin_ws/src/
catkin_create_pkg tutorial rospy
roscd tutorial

And the code used to create the publisher called "tutorial" that publishes on a topic called "/say_hello" was the following:


#! /usr/bin/env python

import rospy
from std_msgs.msg import String

rospy.init_node('tutorial')

publisher = rospy.Publisher('/say_hello', String, queue_size=1)
rate = rospy.Rate(3) # 3hz

while not rospy.is_shutdown():
publisher.publish('Hey! Welcome to Robot Ignite Academy.')
rate.sleep()


So easy, isn't it?

Remember that the python file must be a executable. You cam make it executable with the following command (supposing the name of your file is publisher.py):

chmod +x publisher.py

After running your publisher with "rosrun tutorial publisher.py", you can see what is being published with:

rostopic echo /say_hello

That is it for today, guys. I hope you enjoy the video.

Whether you like the video or not, please leave a comment on the comments section below, so we can interact and learn from each other.