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The MRS UAV System 1.5 is being released and this page needs updating. Please, keep in mind that the information on this page might not be valid.

Connecting to ROS core remotely

ROS allows multiple computers to communicate and share topics and services via a local network. This feature is useful for remote testing and simulations, where different ROS nodes can run on multiple machines as if they were on a single computer.

Server computer, a.k.a., “the robot”

Add following lines to .bashrc:

export ROS_MASTER_URI=http://localhost:11311

Important (skipping these steps may kill ROS on the robot if it disconnects from a wifi):

Do NOT export ROS_IP to .bashrc.
Remove the server’s (the robot’s) own hostname in /etc/hosts except of 127.0.1.1. The top of the /etc/hosts file of robot with hostname dog and IP 192.168.69.123 should look like below. For correct functionality, only one instance of 192.168.69.123 can be present in /etc/hosts. Duplicated instances for IP 192.168.69.123 are not allowed.
```
127.0.0.1 localhost
127.0.1.1 dog
192.168.69.123 dog
```

Client computer, a.k.a., “the notebook”

Add following lines to .bashrc:

export ROS_MASTER_URI=http://<server-hostname>:11311

The <server-hostname> should be specified in /etc/hosts on the client’s computer, and <client-hostname> should be specified on the server computer. You should be able to ping one from another using just its hostname.

When finished, don’t forget to comment or delete the configuration on the client. Otherwise, ROS will not be able to start.

For more information, follow to wiki.ros.org/ROS/Tutorials/MultipleMachines.