billtecteacher's profile - activity

Is KDL used by tf to do transforms or is it a supplement to explicitly do transforms by the programmer instead of letting tf do it? Please forgive my ignorance I've been trying to get a better understanding of tf but am confused by KDL.

This command is done one time only:

echo "source /opt/ros/indigo/setup.bash" >> ~/.bashrc

Once it is appended to .bashrc everytime you open a new terminal the bash script /opt/ros/indigo/setup.bash is run.

You could edit .bashrc in a number of ways to add the line "source /opt/ros/indigo/setup.bash" to the end of the .bashrc file, echo is just a handy way to edit .bashrc.

Fixed problem by reloading Ubuntu 14.04 and ROS-Indigo and sudo apt-get install ros-indigo-navigation

I get the following error from move_base when rviz is run:

[ WARN] [1480802963.679228067]: Timed out waiting for transform from base_footprint to map to become available before running costmap, tf error: 
[ WARN] [1480802968.718639954]: Timed out waiting for transform from base_footprint to map to become available before running costmap, tf error: 
[ WARN] [1480802973.758889303]: Timed out waiting for transform from base_footprint to map to become available before running costmap, tf error: 
terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::lock_error> >'
  what():  boost: mutex lock failed in pthread_mutex_lock: Invalid argument
[move_base-2] process has died [pid 2931, exit code -6, cmd /opt/ros/indigo/lib/move_base/move_base __name:=move_base __log:=/home/ros/.ros/log/03c65bac-b9a5-11e6-a280-0026b6f0bacb/move_base-2.log].
log file: /home/ros/.ros/log/03c65bac-b9a5-11e6-a280-0026b6f0bacb/move_base-2*.log

No errros occured when I tried to set the page up. Did not get to the point of adding information to PAGE. @PAGE@ is the one I can edit. I cannot edit @PAGE@ Writing a Complex Node. Is that ok?

Perhaps you could have your callback collect new data from the topic that would be passed to a lastest_data_off_queue variable to another function that runs at the rate you need for your system to work. If you also needed that second function to run if there is new data then it could be called by your call back as well.

Not sure from what you said why you can't call spin? I believe you can also use instead of spinOnce you can use use equivalent of ros python r = rospy.Rate(rate in hz) and then in the loop r.sleep()

The tutorial is a general purpose tutorial on writing a node with parameters, multiple publishers and subscribes to more than one topic. It is a beginner or intermediate tutorial for sure. Only option when I get is for a package tutorial or stack tutorial which it is not either. See page for new turtorial:

http://wiki.ros.org/action/fullsearch...

Related question is there a review process to approve the tutorials and also review for errors before it can be viewed by others. I see there is a process for code package submissions but not general purpose tutorials. Thanks

OK think I answered by own question or rather a package qt_ros does. Looks like it sets up a thread for Qt so qt does not block ros node. I am thinking could also use any inter-process communication or perhaps ros bridge if not using threads.

Of course its not check rospy.is_shutdown() since its not returning from guy_app while not rospy.is_shutdown(): str = "hello world %s"%rospy.get_time() pub.publish(str) gui_app() rospy.loginfo(str) r.sleep()

I can publish from gui user interface handler for a event like pushing a button but not sure yet if I can listen to a topic (because the gui takes control and won't give it back to node software main loop)?

Was wondering if anyone knows of or has a simple example of a node that uses PyQt that works in hydro? Trying to teach students about framework and thought they would find using it with their own node that display and gets input from gui interesting.

Hi

I am developing a turtlebot variant that does not use an existing turtlebot base. I want to write a driver for it, but am unsure of turtlebot architecture. It seems like the code is tied to the create base or even more so to the kubuki base. I would like to keep base code contained to a single node and new_base_driver.py. Is the turtlebot node the central point used to communicate with the base driver code? Is there a generic base driver module I should work off of? What do you think would be the best way to proceed?

The base will be non-holonomic in one configuration and holonomic in another. In short it can spin about it's center point but also go backwards to pull and push a cart that can be attached to it to carry instruments, sensors, etc.

Rviz does not show the registered point cloud. Running turtlebot software with a create and kinect.

The lock file in last post for some reason was left with a permission which killed the script. I can fix the lock permission and it goes back to error with list of 300+ packages not installed. I think I can learn more myself diving into aptitude command thanks to you.

aptitude was not able to resolve dependencies

Never mind just answered my own comment shoud be sudo apt-get install aptitude not installed by default on 12.04

ubuntu@ubuntu:~$ sudo aptitude install ros-hydro-desktop-full sudo: aptitude: command not found ubuntu@ubuntu:~$ sudo apt-get aptitude E: Invalid operation aptitude ubuntu@ubuntu:~$ How does one get aptitude on to system?

Trying to setup a USB stick with ROS for a student. Get to the following command and I get this error:

ubuntu@ubuntu:~$ sudo apt-get install ros-hydro-desktop-full Reading package lists... Done Building dependency tree
Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:

The following packages have unmet dependencies: ros-hydro-desktop-full : Depends: ros-hydro-desktop but it is not going to be installed Depends: ros-hydro-mobile but it is not going to be installed Depends: ros-hydro-perception but it is not going to be installed Depends: ros-hydro-simulators but it is not going to be installed E: Unable to correct problems, you have held broken packages. ubuntu@ubuntu:~$

Am using UBUNTU 12.04 Live and UNETBOOTIN loader.

Was wondering how to proceed to fix it?

Thanks

what do you mean by adding wire and taking it out. Wondering if it the code associated with wire that is causing the problem and not wire.h?

The example i gave in comment worked over a wifi. Were you able to ping over wifi each way?

Rosserial is sending receiving and sending ros topics or messages. The message will need a ros header on it but could be a string of some length that contains your json information you are trying to convey. Ros serial is like ros bridge but connects to a serial line. Ros bridge uses tcp/ip but once again it is I think a ros topic message and above applys to it.