Elizabeth C's profile - activity

The message is telling you that you have too many recursive method calls. From looking at the code, this appears to be because you're calling get_joint() from within get_joint() (under while not rospy.is_shutdown() ).

The problem is most likely in your code and has nothing to do with rosrun. It appears that your node did start, but it didn't keep running for very long. For the node to continue running, it has to either continuously be doing things (for example: while not rospy.is_shutdown(): #do stuff), or include rospy.spin() somewhere to keep it running after initialization is done. (You can see examples of both of those in this tutorial.)

If that wasn't the problem, you'll need to post your code before anyone will be able to help you.

EDIT: The actual problem appears to have been that a return statement was placed too early a method. Fixing this revealed another problem with infinite recursive method calls.

The USB port isn't set to writable. Run sudo chmod a+rw /dev/ttyUSB0 to make it writable by all users.

You can add a udev rule to make USB ports be writable by all users by default. Make a file called 75-usb-rw.rules in /etc/udev/rules.d and add the following to it:

SUBSYSTEMS=="usb", KERNEL=="ttyACM[0-9]*", MODE="0666"
SUBSYSTEMS=="usb", KERNEL=="ttyUSB[0-9]*", MODE="0666"

Instructions are added. Unfortunately I STILL can't post any direct links (like the specific path to the tag in the svn repository) until I get enough upvotes on my questions and answers to get 30 karma. :(

Does ANYONE have contact sensors working with Gazebo and Fuerte? If so, how did you get them working? I have sensors defined in the urdf of my model (and all the links have <collision> blocks), and the topics for the sensors are being advertised, but whenever I try to subscribe to the topics, I get a variation on this each clock cycle I'm subscribed to the topic:

Error [ContactSensor.cc:237] Contact Sensor[sensor_name] has no collision[link_name_geom]

At least part of the issue seems to have been fixed (Gazebo bitbucket issue 141), but I don't think the fix has made it to the released version yet. Also, issue 244 might still create problems, and a comment on issue 141 makes it sound like the bumper plugin might have problems as well. (Sorry about the lack of real links.)

The link 1Daniel1 posted has the correct information about how to add a pressure sensor (also known as a bumper) to the URDF of a model. However, whenever you try to listen to the contact sensor topic, you'll most likely get a variation on this message:

Error [ContactSensor.cc:237] Contact Sensor[contact_sensor] has no collision[base_link_geom]

This is because the contact sensor implementation is broken in the version of Gazebo that comes with Fuerte. The comment thread on Gazebo bitbucket issue 13 has information about how to get a version of Gazebo with working contact sensors. (I'd link to it, but I don't have enough karma.)

I don't think that message is your fault--it's because the contact sensor implementation is broken in the version of Gazebo that comes with Fuerte. At least one of the bugs causing the problem is now fixed, but the fix hasn't made it to the released version yet. It also sounds like that there might be bugs in the bumper implementation itself (based on this and this).

EDIT: Thomas Koletschka's comment has information about how to get a working version of Gazebo, which I've included and expanded below.

Installing a new version of Gazebo

• Choose somewhere to put your new version of Gazebo. I put mine in ~/ros/simulator_gazebo, and I'll assume that's the location for the rest of the instructions.
• $ mkdir ~/ros
• $ svn co https://code.ros.org/svn/ros-pkg/stacks/simulator_gazebo/tags/simulator_gazebo-1.7.11/ ~/ros/simulator_gazebo
• In your ~/.bashrc (or wherever it is that you set your ROS_PACKAGE_PATH), add ~/ros/simulator_gazebo to ROS_PACKAGE_PATH before the original value. For example:
  export ROS_PACKAGE_PATH=~/ros/simulator_gazebo:$ROS_PACKAGE_PATH
• $ source ~/.bashrc
• $ rosmake -i simulator_gazebo (-i means put a ROS_NOBUILD in the directories)
  This took about 30 minutes to run successfully. The first time I tried running it, I got this:
  -- BUILD ERRORS: These must be resolved before compiling.
-- Missing: Google Protobuf Compiler Library (libprotoc-dev)
-- Missing: libtar
  so I did:
  $ sudo apt-get install libprotoc-dev libtar-dev
  and tried again, and it worked.

When you launch Gazebo as usual, you'll get the new version you just compiled, and it should have semi-working contact sensors (with the caveats mentioned above). Be aware though that it's possible existing models you want to use might be incompatible with this new version.

EDIT 4/9/2013: The issue seems to have been resolved as of Gazebo 1.3, which is included in the simulator-gazebo-1.7.11 tag.

The rospy code API docs seem to be broken right now. The "Code API" link on the wiki page for rospy goes to a directory with nothing useful in it. Unless I'm massively missing something and looking in the wrong place, can someone either fix this, or direct me to the correct place to report the problem?

I'm having a similar problem. Based on this open issue, it looks like the problem might be caused by a bug in Gazebo: https://bitbucket.org/osrf/gazebo/issue/141/contact-sensor-state

(Sorry that's not actually much help.)

After starting a thread like this:

threading.Thread(target=self.__update_servo_states).start()

calls to rospy.log* from within __update_servo_states don't display anything. Does anyone know why that might be happening and what I can do to fix it? (I'm using a modified version of the dynamixel_motor stack, but the line of code above is directly from the original version.)