Robotics System Toolbox custom message stops working R2016b

After following all instructions downloading the plug in and creating custom messages from package I was able to succesfully use ROS custom messages - until I tried running the exact same code a few weeks later "Cannot find a MATLAB message class for type pkg/custom". Running the

rosgenmsg(folderpath)

command again doesn't even work: Undefined function or variable 'rosgenmsg'. It's as if the plugin is gone. This has happened twice already and the only solution is to re-download the plugin and redo the custom message from package. Any help in figuring out why this keeps happening would be appreciated.

Answer 1

[Archita P]

It might be the case that the package name in the package.xml file does not match the folder name.

Unfortunately, the code makes the assumption that the two always match and that causes the behavior you are seeing. Try renaming the folder so that the two names match.

Also, you can try to install the following add-on,

>> roboticsAddons

Then select the 'ROS Custom Messages' add on to install.

The default folder for this add-on is the following -

C:\ProgramData\MATLAB\SupportPackages\R2016b\toolbox\robotics\supportpackages\roscustommsg\

Add this to the MATLAB path -

>>addpath(genpath('C:\ProgramData\MATLAB\SupportPackages\R2016b\toolbox\robotics\supportpackages\roscustommsg\'))

Restart MATLAB and see if it works.

[Alexander]

adding and saving the path 'C:\ProgramData\MATLAB\SupportPackages\R2016b\toolbox\robotics\supportpackages\roscustommsg\' worked. thanks