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i got problems with roslaunch learning_nxt robot.launch

asked 2017-11-14 22:04:14 -0500

luisitomzt gravatar image

updated 2017-11-16 12:59:30 -0500

i got this error when i try this command on console :

$ roslaunch learning_nxt robot.launch

process[nxt_ros-2]: started with pid [23000] 

Traceback (most recent call last):

  File "/home/luis/nxt/src/nxt_ros/src/nxt_ros/nxt_ros.py", line 37, in <module>
    import nxt.locator

ImportError: No module named nxt.locator

Update:

i'll describe the process to create the package first at home directory:

mkdir nxt
cd nxt
git clone --recursive https://github.com/NXT-ROS/nxt.git src

then on the root of the package directory

catkin_make (everything goes fine)
source devel/setup.bash

until this point everything is ok

then when i try this:

roslaunch nxt_ros_test test.launch

or

roslaunch learning_nxt robot.launch

both have the same problem

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Comments

Welcome! What version of ROS are you using and what OS? Can you please provide a link to the package that you're using? Is it this nxt_ros? Are you using a simulator or a physical robot?

jayess gravatar image jayess  ( 2017-11-15 01:29:19 -0500 )edit

@luisitomzt: I moved your updated info to your question, but in the future please don't use an answer to give more info about your question

jayess gravatar image jayess  ( 2017-11-15 16:15:47 -0500 )edit

I'm a little confused by this new info. Are you using a catkin workspace? Or, are you just doing everything from a regular folder that you created in your home directory?

jayess gravatar image jayess  ( 2017-11-15 16:16:46 -0500 )edit

i created a folder in home/my user/ called “nxt”. Then in this folder I cloned nxt_ros using the command I mentioned before. By executing catkin_make the folder I created becomes a catkin workspace isn’t it?

luisitomzt gravatar image luisitomzt  ( 2017-11-15 17:59:40 -0500 )edit

Yes, but you need to put your packages in the src folder inside the workspace. Checkout my updated answer and let me if it helps/you need further clarification.

jayess gravatar image jayess  ( 2017-11-15 18:31:26 -0500 )edit

So, I took a look at the README and it says that you need to use catkin buildnotcatkin_make. This could be the source of your problem.

jayess gravatar image jayess  ( 2017-11-15 18:40:05 -0500 )edit

i installed python-catkin-tools for using catkin build. then erased the nxt workspace and make it again for a clean installation. i followed the steps i mentioned before, but the problem persist.

luisitomzt gravatar image luisitomzt  ( 2017-11-15 19:29:46 -0500 )edit

Did you use catkin_make? If so, that is not compatible with catkin build. You can't use catkin_make with catkin_tools. Try again following the instructions in my answer (or the repo's README).

jayess gravatar image jayess  ( 2017-11-15 19:32:16 -0500 )edit

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answered 2017-11-16 12:59:02 -0500

luisitomzt gravatar image

updated 2017-11-17 02:00:22 -0500

i already fixed the problem with the missing module nxt.locator, what i've done to fix the problem is to install the following packages from nxt-python:

version 2.2.2 of nxt-python from here:

and PyBluez, PyUSB and Pyfantom

all installed by executing sudo python setup.py install

By doing that, the missing module nxt.locator problem was solved.

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answered 2017-11-15 01:35:54 -0500

jayess gravatar image

updated 2017-11-15 19:34:23 -0500

If you're using this version of nxt_ros then you'll need to run catkin_make from the root of the directory and then source your setup.bash to make the Python modules available.

~/catkin_ws/$ catkin_make
~/catkin_ws/$ source devel/setup.bash

Or, you haven't downloaded/compiled/installed the package with the required nxt.locator module.


Update:

The README shows that you need to use catkin build to compile. If you're using catkin_make you're going to have issues (as it appears you are) because these two are incompatible (as far as I know). From the README:

~$ mkdir nxt
~$ cd nxt
~/nxt$ git clone --recursive https://github.com/NXT-ROS/nxt.git src
~/nxt$ catkin init # initialize the workspace
~/nxt$ catkin build # build all packages

Take a look at the docs for catkin_tools for more information.

Note: I updated this (again) to reflect the README of the repo.

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Comments

i used the package you mentioned, run catkin_make on the root of my workspace, and then sourced setup.bash everything goes fine at this point. then i try to launch the test package with "roslaunch nxt_ros_test test.launch" and the error keep showing. ImportError: No module named nxt.locator

luisitomzt gravatar image luisitomzt  ( 2017-11-15 13:36:11 -0500 )edit

Thank you for you patience, but the nxt_ros package is inside the src folder. It was created when I executed the command “git clone —recursive https://github.com/NXT-ROS/nxt.git src” this created src folder inside ~/nxt folder

luisitomzt gravatar image luisitomzt  ( 2017-11-15 18:36:41 -0500 )edit

Right, I didn't notice the src at the end of your command. I've updated my answer.

jayess gravatar image jayess  ( 2017-11-15 18:41:05 -0500 )edit

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Asked: 2017-11-14 22:04:14 -0500

Seen: 275 times

Last updated: Nov 17 '17