SOme help with launch files

navigation

asked 2013-11-17 10:02:22 -0500

Massbuilder
71 ●16 ●18 ●22

updated 2013-11-18 07:43:54 -0500

jarvisschultz

9031 ●58 ●128 ●143 https://www.linkedin.c...

In response to a request for the launch file and the error. Here is the launch file,

<launch>
  <node pkg="newrobot" type="/src/usb.py" name='base_scan' output="screen">
  </node>

  <node pkg="newrobot" type="src/odompublish.py" name="odom" output="screen">
  </node>

  <node pkg="newrobot" type="src/odompublish.py" name="base_pos" output="screen">
  </node>
</launch>

And the error message

ERROR: cannot launch node of type [newrobot/src/usb.py]: newrobot
ROS path [0]=/opt/ros/groovy/share/ros
ROS path [1]=/opt/ros/groovy/share
ROS path [2]=/opt/ros/groovy/stacks
ERROR: cannot launch node of type [newrobot/src/odompublish.py]: newrobot
ROS path [0]=/opt/ros/groovy/share/ros
ROS path [1]=/opt/ros/groovy/share
ROS path [2]=/opt/ros/groovy/stacks
ERROR: cannot launch node of type [newrobot/src/odompublish.py]: newrobot
ROS path [0]=/opt/ros/groovy/share/ros
ROS path [1]=/opt/ros/groovy/share
ROS path [2]=/opt/ros/groovy/stacks

edit retag flag offensive close merge delete

Comments

Can you post the .launch file you are trying to launch and the full error you get?

Tirjen ( 2013-11-17 19:24:52 -0500 )edit

`type` is the binary to launch.

dornhege ( 2013-11-17 22:00:12 -0500 )edit

add a comment

2 Answers

Sort by » oldest newest most voted

answered 2013-11-18 02:52:00 -0500

dornhege

31395 ●134 ●284 ●498

Remove all the paths in the type, e.g. /src/usb.py should be usb.py. ROS finds this by itself.

edit flag offensive delete link

Comments

Also, since you are using Python-based nodes, make sure that your files have executable permissions or ROS won't find nodes of that type e.g. `chmod a+x [PATH_ON_ROS_PACKAGE_PATH]/newrobot/src/usb.py`

jarvisschultz ( 2013-11-18 07:41:37 -0500 )edit

one question I use a class for the laser scan publisher that called within usb. Do I use usb ore the node that makes up the class?

Massbuilder ( 2013-11-18 07:49:30 -0500 )edit

IS the catkin workspace suppose to be the ROS directory? I got mine in seperate. Could be what causing the problem

Massbuilder ( 2013-11-18 09:56:41 -0500 )edit

As @dornhege mentioned above, the `type` field is the Python script to run. Regardless of how imports are structured and what classes are involved, the "top-level" script is what goes in the `type` field.

jarvisschultz ( 2013-11-18 11:38:46 -0500 )edit

Let's say your catkin ws is at *~/catkin_ws/*, then your package should be in *~/catkin_ws/src/*. Therefore, one of your example nodes would be *~/catkin_ws/src/newrobot/src/usb.py*. If everything is working, TAB key should autocomplete both the package name, and the nodename when using `rosrun`.

jarvisschultz ( 2013-11-18 11:41:48 -0500 )edit

Seems the tab is not working, is there another way to find the package path

Massbuilder ( 2013-11-19 01:05:58 -0500 )edit

The command `echo $ROS_PACKAGE_PATH` will print out the current package path. In the above example *~/catkin_ws/src* should be listed in that output if it's not, try `source ~/catkin_ws/devel/setup.bash`. I'm assuming you setup a workspace http://wiki.ros.org/catkin/Tutorials/create_a_workspace

jarvisschultz ( 2013-11-19 03:59:58 -0500 )edit

add a comment

answered 2013-11-18 02:07:14 -0500

Tirjen

808 ●9 ●18 ●28

It seems like your launch file can't find your package. From the error I can also see that it is searching only in the installation directories, so it seems that you have not created any workspace. Where is located this newrobot package? To see if ROS is able to find it try to run 'rospack find newrobot' and see if it can find it.

edit flag offensive delete link

Comments

You are on to something. I tried what you suggested and it found nothing.

Massbuilder ( 2013-11-18 07:44:01 -0500 )edit

If ROS can't find your package it means that maybe you put it into a wrong folder... Where is located your packege? You have to add its path to the ROS_PACKAGE_PATH.

Tirjen ( 2013-11-18 21:20:55 -0500 )edit

How do I do that?

Massbuilder ( 2013-11-19 01:17:47 -0500 )edit

If you haven't done it, create a workspace in your home folder then add to your .bashrc the following line: 'export ROS_PACKAGE_PATH=~/ros_workspace:${ROS_PACKAGE_PATH} ' Finally put your packages in the workspace folder.

Tirjen ( 2013-11-19 20:00:11 -0500 )edit

add a comment

SOme help with launch files

Comments

2 Answers

Comments

Comments

Question Tools

Stats

Related questions

SOme help with launch files edit

Comments

2 Answers

Comments

Comments

Question Tools

Stats

Related questions

SOme help with launch files