Successful use of wifi_comm?

Question

Dear All,

I was just wondering if anyone successfully managed to use wifi_comm.

As far as I know I followed the instructions to the letter, successfully managed to install olsrd and also make the wifi_comm.

wifi_discovery_node and wifi_com_example are running fine.

I have 2 laptops connected Ad-Hoc, each running the software.
I can see their IP addresses on olsrd and also in the topic list. Ping works from one machine to another and also SSH, so presumably the network connection is fine.

In my case I would see

/wifi_hello_world
/wifi_hello_world_192_168_20_100
/wifi_hello_world_192_168_20_101
/wifi_neighbours_list

amongst others.

Hello World is being generated in each machine and can be seen when using
rostopic echo /wifi_hello_world

Also, machine with IP 192_168_20_100 can see data streaming in /wifi_hello_world_192_168_20_100, again using rostopic echo /wifi_hello_192_168_20_100
Somehow though data (Hello World) is not being transferred from one machine to the other and machine with IP 192_168_20_101 keeps waiting for data to be sent in.

Looks like the problem is somewhat related to foreign_relay (as same happens when I just use that)

Any help is greatly appreciated. Thanks in advance

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Originally posted by roboviz on ROS Answers with karma: 26 on 2011-07-13

Post score: 0

Answer 1

Sorted...

Basically, the IP Addresses have to be specifically defined either in every window used or better by modifying the .bashrc file

export ROS_MASTER_URI=http://192.168.20.100:11311 and
export ROS_IP=http://192.168.20.100

for one end and

export ROS_MASTER_URI=http://192.168.20.101:11311 and
export ROS_IP=http://192.168.20.101

for the other.

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Originally posted by roboviz with karma: 26 on 2011-07-26

This answer was ACCEPTED on the original site

Post score: 0

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Original comments

Comment by Per Lenander on 2011-12-21:
I have the exact same problem you had (with foreign relay, not wifi_comm) and I've tried the above solution, but without improvement. I still get the empty topic popping up on the foreign master without any data in it: http://answers.ros.org/question/3388/foreign_relay-problem