csherstan's profile - activity

I don't suppose anyone knows why this is a problem in python3? I'd really prefer not to switch back to 2.7.

I'm running indigo on Ubuntu 14.04. Running this command causes apt to uninstall ROS for me.

Turns out the problems were much larger. Something must have gone very bad during the install. A complete removal and reinstall of Kinetic did the trick. Things are working fine now with ros-kinetic-ros-base.

I am an experienced ROS installer. I just did a new install of Kinetic on a Raspberry Pi 3, running Ubuntu 16.04. I installed sudo apt-get install ros-kinetic-desktop and followed the rest of the instructions: http://wiki.ros.org/kinetic/Installation/Ubuntu#kinetic.2BAC8-Installation.2BAC8-PostInstall.Tutorials

I then when through setting up my workspace: http://wiki.ros.org/ROS/Tutorials/InstallingandConfiguringROSEnvironment

However, after sourcing both source /opt/ros/kinetic/setup.bash and source devel/setup.bash I check the var echo $ROS_PACKAGE_PATH but I only see /opt/ros/kinetic/share:/opt/ros/kinetic/stacks. My local workspace is missing.

Bug? Thanks.

Yup, Ryan and Tom for the win. Thanks guys.

For recognizers you can also check out gspeech and pocketsphinx.

And audiocapture for recording audio.

Thanks, but that's not it. There was a demo of a cool html based tool that allowed you to visualize package usage and number of bugs, etc.

Hey for those of you who were at ROSCon 2014 in Chicago there was a slick looking demo showing how many usage statistics of different packages, number of bugs, etc. I think it also showed a map of users geographically. I think it might have been demoed during a lightning talk, not sure.

I am NOT referring to this map: http://metrorobots.com/rosmap.html

Anyone know what I'm talking about or where it's located?

Well I've confirmed what you've said with tests. However, it would be really nice if messages were timestamped according to when they were published rather than received. So the callback for a subscriber would now have an extra parameter:

def callback(msg, timestamp):

Indigo, Linux Mint 17

I'm using the commandline rosbag utility to record various topics.

I have two topics /topic1 and /topic2. Topic1 is published before Topic2, like so:

if state==new_state:
      publish_topic_1()

publish_topic_2(state)

So topic1 publishes when we are in the new_state and topic2 just publishes the state, whatever it happens to be. After recording I inspect the bag with rqt_bag. I expect to see topic1 always preceding topic2 switching from another state to "new_state". However, this is not what I see. I often will see topic2 transition to "new_state" before topic1 appears. If I explicitly add a sleep statement after publishing topic1 then they appear in the order I expect.

So:

• What should I expect for timing topics? Should I expect them to be received and recorded in order? My understanding was that rosbag would handle synchronization of all my data streams.
• Does adding a Header to each msg type help?
• Is everything fine and rqt_bag is just broken?

Does it all come to the limitations of record/playback as described here? http://wiki.ros.org/ROS/Tutorials/Rec...

If so, does anyone have a solution for ensuring accurate timing in a rosbag? Writing it directly myself rather than publishing and letting rosrecord pick it up?

I seem to have gotten it sorted out.

Cause: No idea. Bug in out of date ROS binaries?

Solution:

 sudo apt-get upgrade

The problem is that I'm stuck on Raring, which is end of life and upgrade and update don't work properly any more. I had to figure out which sources to point apt-get at. Once I did that and ran upgrade the issue with serious delays in this particular situation went away.

So either I go back to 12.04 or hope that National Instruments updates their DAQ drivers soon so I can move forward to 14.04.

I see the issue has been corrected in the hydro branch, but not in groovy. Line 213 on https://github.com/turtlebot/turtlebo... needs to be removed.

I haven't tried that package, but it does not appear to be supported any more. I have had luck with the turtlebot_create package http://wiki.ros.org/turtlebot_create although if I recall correctly I had to make a fix to the serial port initialization.

This is for the dynamixel_controllers package ( http://wiki.ros.org/dynamixel_control... ), but I don't think it's specific to this particular package. The package is installed from source in my catkin_workspace, not from binaries.

Ok, I have 5 callbacks (JointController.process_motor_states, 5 instances of JointController) that subscribe to a topic (MotorState.msg) that is being published at 20Hz, so 0.05s. Each of the callbacks also publishes a message (JointState.msg). Now timing the callbacks I see that summing up all 5 takes longer than 0.05 s and is creating a bottleneck. So what is happening is that process_motor_states ends up falling way behind and gets further and further out of sync as time goes on. Further inspection of the process_motor_states shows that the bottleneck is the publishing of the message (JointState.msg), which itself can take up to 0.05s. So in the code snippet below, the issue is the last line.

def process_motor_states(self, state_list):
    if self.running:
        state = filter(lambda state: state.id == self.motor_id, state_list.motor_states)
        if state:
            state = state[0]
            self.joint_state.motor_temps = [state.temperature]
            self.joint_state.goal_pos = self.raw_to_rad(state.goal, self.initial_position_raw, self.flipped, self.RADIANS_PER_ENCODER_TICK)
            self.joint_state.current_pos = self.raw_to_rad(state.position, self.initial_position_raw, self.flipped, self.RADIANS_PER_ENCODER_TICK)
            self.joint_state.error = state.error * self.RADIANS_PER_ENCODER_TICK
            self.joint_state.velocity = state.speed * self.VELOCITY_PER_TICK
            self.joint_state.load = state.load
            self.joint_state.is_moving = state.moving
            self.joint_state.header.stamp = rospy.Time.from_sec(state.timestamp)

            self.joint_state_pub.publish(self.joint_state)

Here's the JointState.msg:

Header header
string name         # joint name
int32[] motor_ids   # motor ids controlling this joint
int32[] motor_temps # motor temperatures, same order as motor_ids

float64 goal_pos    # commanded position (in radians)
float64 current_pos # current joint position (in radians)
float64 error       # error between commanded and current positions (in radians)
float64 velocity    # current joint speed (in radians per second)
float64 load        # current load
bool is_moving      # is joint currently in motion

There is one subscriber for each of the instances of this publisher:

rospy.Subscriber('/%s/state' % controller_name, JointState, self.state_update)

If the subscriber callback for the JointState.msg is simply a pass statement so:

def state_update(self, joint_state):
      pass

Then we still have the bottleneck. If I remove the single subscriber then there is no bottle neck.

Any help is welcome. I don't think I'm doing anything weird here.

I have a custom message /adc_interface/EMGSignal. If I run rosmsg show EMGSignal it displays the message correctly. However, if I try to run rostopic echo /adc_interface/EMGSignals I get:

ERROR: Cannot load message class for [adc_interface/EMGSignal]. Are your messages built?

I also get a similar error when trying to use rqt_plot.

The message has been tested and used on Groovy on another computer. I am running Hydro on my computer.

I have run catkin_make. My .bashrc is:

source /opt/ros/hydro/setup.bash
export ROS_PACKAGE_PATH="/home/craig/Documents/workspace/551/project":$ROS_PACKAGE_PATH

I am new to Ros and may have some configuration/installation issues (I thought it would be fun to uninstall python from Linux Mint - it wasn't).

Additionally, running roswtf produces:

Loaded plugin tf.tfwtf
No package or stack in context
================================================================================
Static checks summary:

Found 1 warning(s).
Warnings are things that may be just fine, but are sometimes at fault

WARNING You are missing core ROS Python modules: rosrelease -- 

Found 1 error(s).

ERROR Not all paths in ROS_PACKAGE_PATH [/home/craig/Documents/workspace/551/project:/opt/ros/hydro/share:/opt/ros/hydro/stacks] point to an existing directory: 
 * /opt/ros/hydro/stacks

================================================================================
Beginning tests of your ROS graph. These may take awhile...
analyzing graph...
... done analyzing graph
running graph rules...
... done running graph rules

Online checks summary:

Found 2 warning(s).
Warnings are things that may be just fine, but are sometimes at fault

WARNING The following node subscriptions are unconnected:
 * /rosout:
   * /rosout

WARNING The following nodes are unexpectedly connected:
 * unknown (http://gunstar:50711/)->/rosout (/rosout)

I am attempting to do a ROS install on Raspbian (pi). 3.10.25+

Pretty much everything has gone very well until I tried to install the tf2_bullet package that I need for create_node.

To install new packages I have been following the instructions here: http://wiki.ros.org/ROSberryPi/Settin...

Running

rosdep install  --from-paths src --ignore-src --rosdistro hydro -y --os=debian:wheezy

I get the error:

ERROR: the following packages/stacks could not have their rosdep keys resolved to system dependencies:
tf2_bullet: No definition of [bullet] for OS version [wheezy]

I have manually installed bullet on my system from source (although I'm not sure I did it right).

I've already checked and create_node does in fact need tf, which depends on tf2 down to bullet.

I see in the source for rosdep that it does a look up in the data dictionary passed in to RosdepDefinition, but I haven't yet found where that data dictionary is created.

Anyone know how to get bullet installed or how I can get rosdep to move past this point?

Thanks