ROS

This page gathers commands and examples on how to setup and use ROS Melodic with PolyVR.

ROS package installation under Ubuntu

WARNING: You can put the following lines in a script, but Do NOT execute it as sudo!

sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'
sudo apt-key adv --keyserver hkp://pool.sks-keyservers.net --recv-key 0xB01FA116
sudo apt-get update
sudo apt-get install ros-melodic-ros-base ros-melodic-rospy ros-melodic-rosbridge-server ros-melodic-common-tutorials ros-melodic-rospy-tutorials
sudo rosdep init
rosdep update
echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc
source ~/.bashrc

PolyVR python example

You can use the following code in polyvr to subscribe to a ROS topic

import VR, sys
# change path accordingly!
sys.path.append('/opt/ros/melodic/lib/python2.7/dist-packages')
import rospy, std_msgs

def callback(data):
	print data
	return

rospy.init_node('polyvr')

def initROS():
	rospy.Subscriber('/listener', std_msgs.msg.String, callback)
	rospy.spin()

tID = VR.startThread(initROS)

publish a topic

• write in a terminal roscore
• write in another terminal: rostopic pub /listener std_msgs/String "Hello, World"

Web example

Usefull commands

Start a master

roscore

Listen to topic

rostopic echo /my/topic

make a dump of the network traffic

rosbag record -a

play back the network dump (open a master in another console)

rosbag play 2015-06-29-16-40-23.bag

list all available topics

rostopic list