R2015a Robotics System Toolbox: Cannot subscribe to topics on Windows MATLAB node

I have my roscore running on my Ubuntu machine which is running the Gazebo simulator. I configured the MATLAB node with the ROS_MASTER_URI environment variable and I can see the topics generated from the simulator using 'rostopic list' however I cannot subscribe or echo any of the topics on MATLAB. How do I fix this?

Answer 1

[MathWorks Support Team]

Please add the host name and IP address of your Ubuntu machine to the 'C:\Windows\System32\drivers\etc\hosts' file. In the 'hosts' file add the IP address and host name as shown below.

For example,

102.54.94.97     <Linux Host Name>

To initialize the MATLAB rosnode, please run the following commands when connecting to the network:

>>rosshutdown();
>>rosinit('<Linux Host Name', 'NodeHost', '<Windows Host Name>')

You should then be able to subscribe and echo topics that are published over the network.

Answer 2

[Mark Levin]

Hi! I have the same problem - I use Clearpath Jackal robot as a ros master and I try to connect with Robotics Toolbox of Matlab 2015a. I have no problem to publish, it means, robot moves as I want, but every time I do subscribe I get the same answer, that the time is gone and no message was gotten. In summary, - I can see the rostopic list - I can control the robot by publishing - I can't get messages. What can I do? I tried to update hosts file - I added the robot's IP and put some name (does it matter what name do I use?) and then even publishing doesn't work. Thank in advance!

[Chawki CRTL]

I have the same problem too, did you resolve it Mark Levin ?

[Jacob Heathorn]

Try the following:

https://www.mathworks.com/matlabcentral/answers/119559-why-is-the-ros-subscriber-callback-in-matlab-not-triggered-when-messages-are-published-from-an-exter

[sam]

I had the same issue with the Clearpath Jackal but the issue was resolved after following along with wjchen84's solution in https://www.mathworks.com/matlabcentral/answers/196911-use-matlab-robotics-system-toolbox-to-receive-ros-message. For me that meant only updating the 'hosts' file on both the Jackal and the external computer running MATLAB/Simulink.