communication problem with laptop and workstation - turtlebot
I am having a problem with my workstation communicating with the turtlebot netbook. from the netbook, I can run rviz or
rosrun image_view image_view image:=/camera/rgb/image_color
and I will receive an image. When I try the same from the workstation, I received no image. In rviz it says no images received, in image_view a small white windows opens. I believe I have set the ROS_MASTER_URI and the ROS_HOSTNAME correctly since I can publish from the workstation and subscribe from the laptop. I can not subscribe from the workstation though, it doesn't say the topic isn't being published, all that it does is end the line in the terminal and has a blinking cursor on a blank line. I ctrl C to stop the subscribing since nothing shows up. Also, when I run :
rqt -s kobuki_dashboard
or this:
roslaunch turtlebot_rviz_launchers view_robot.launch
From the turtlebot netbook, it runs perfectly fine. However, when I run it from the workstation the first one comes up but doesn't appear to be connected to the turtlebot. It says "Last message received 1372357558 seconds ago". When I run the second command (rviz) it comes up with just a create base. On the netbook It comes up correctly with the full turtlebot and kobuki base. Any help is appreciated and if more information is needed just ask. Thanks
Edit: Also, running rxgraph from the workstation shows that none of the nodes are connected (they are all red circles)
Can you tell us how did you set ROS_MASTER_URI and the ROS_HOSTNAME on the workstation and on the laptop ? And have you synchronized workstation and laptop ? For this, you should use chrony: sudo ntpdate ntp.ubuntu.com or sudo ntpdate MasterIP. it may be the cause of "message received seconds ago"
I have already synchronized the workstation and laptop but I just resynchronized them using sudo ntpdate http://ntp.ubuntu.com. The laptop ip is 192.168.1.4 the workstation ip is 192.168.1.3 on the workstation the ROS_MASTER_URI is http://192.168.1.4:11311 the ROS_HOSTNAME is 192.168.1.3. The latptop
ROS_HOSTNAME is 192.168.1.4 and the ROS_MASTER_URI is http://localhost:11311. I did not set the ROS_MASTER_URI. I setup the laptop according to the directions in the tutorial (under robots, turtlebot, network setup for the Live USB Installation, and the workstation according to the directions also
I believe explicitly setting the ROS_MASTER_URI on the turtlebot fixed my problem. Thank You!