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Laptop connected to roscore host, does not receive messages

asked 2012-04-25 00:36:50 -0500

Hansg91 gravatar image

updated 2014-01-28 17:12:05 -0500

ngrennan gravatar image


I was having some problems setting up my wifi network with a laptop and a pandaboard. The pandaboard starts its own wifi network through hostapd and the laptop connects to that network. The ROS_MASTER_URI is correctly set (ROS_HOSTNAME too, to '', but I'm not sure it's still required) to (Pandaboard) and the laptop can indeed communicate with the roscore (doing for example rostopic list gives me the correct list of currently active topics).

However if I do the following command on the laptop :

rostopic pub -r 1 /test std_msgs/String hello


rostopic echo /test

on the pandaboard, no messages are received. If I switch 'roles', no messages are received either. If I send and echo on the pandaboard, it does display messages. If I send and echo on the laptop, no messages are displayed.

If I connect both to my home network and set the ROS_MASTER_URI to its local IP everything works fine, but I don't always have such a network available... Is there something wrong with my hostapd network?

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answered 2012-04-25 03:46:51 -0500

michikarg gravatar image

Did you check all the steps at:

Also i had some trouble with some entries in the /etc/hosts file since the entries there usually overwrite the information from the DNS/DHCP Server. If you have some entries there, you can make a backup of your /etc/hosts file and delete every entry except the following:   localhost

At least this was the cause for a similar problem in a network with non-static IP addresses....

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Thanks, that seems to have helped me.

Hansg91 gravatar image Hansg91  ( 2012-04-25 10:33:16 -0500 )edit

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Asked: 2012-04-25 00:36:50 -0500

Seen: 834 times

Last updated: Apr 25 '12