Questions tagged [rostopic]

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Inconsistency between ros2 topic hz and bw

I have run into some unexpected behavior reflected in the outputs of ros2 topic hz and ros2 topic bw. Context: I am building a ...
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Подключение дополнительных камер к образу который использует ROS

Всем привет. В ROS не разбираюсь. Столкнулся с проблемой подключения дополнительных камер на raspberry pi 4 с использованием образа clover_v0.23.img. Моя зада состоит в том, чтобы подключить камеру ...
serpent's user avatar
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1 answer
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How to add an additional argument in a ROS2 cpp callback

I want to add an additional argument in a callback function for rclcpp, e.g. callback(msg, additional_argument). I can do it in ...
gab's user avatar
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/map topic not receiving any data (but still published)

I'm using Ubuntu 20.04 on a Raspberry Pi 4 B and I'm trying to use the /map topic with my LiDAR. However, when I open Rviz to visualize it, a "Warn" error appears that says "No map ...
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CycloneDDS is not working well ROS_LOCALHOST_ONLY=1 in ros2 humble

First, I configure the .bashrc file with: export RMW_IMPLEMENTATION=rmw_cyclonedds_cpp export ROS_LOCALHOST_ONLY=1 But I got following error when run any ros ...
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Data sent over ROS2 topic is not reliable

Hello everyone of this wonderful forum. I am currently doing my first ROS2 project in which i have send data of aruco id that includes its [id number,x,y,z,orientation] data. I am sending this data ...
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Is it possible to record or log specific topics in ROS2 without publishing?

I apologize if this is a somewhat naive question, but I don't really know much about ros2's architecture beyond basic utilization. I'm a student working in autonomous vehicle research, and my team ...
2muchdata's user avatar
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Issue with Rostopic Name Length Affecting Node Communication

I've been encountering a rather puzzling issue related to the length of a Rostopic name in my ROS (Robot Operating System) setup, and I'm hoping someone can shed some light on it. Here's the situation:...
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ROS2 Topic Echo does not work after ROS2 reinstallation

I recently had to uninstall ROS2 Iron and install ROS2 Humble using sudo apt uninstall ros-* after uninstalling I did ...
Ian Reid's user avatar
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2 answers
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How to find formating for rosmsg publishing on command line

I want to publish messages to my robot in order to get it to move in the command line but I can't figure out how to format the rostopic pub /topic /type . I'm having issue with the data and how to ...
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Why do I need a sleep before publishing first message to a topic?

I am trying to get an explanation for some code that works. To simplify the general issue, I created a bag file with exactly 2 messages with exact same header time stamp down to nano seconds. First ...
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1 answer
182 views

Reading from topic once using rospy.wait_for_message()

Hi, I want to read a message from a topic once, thus I tried to use wait_for_message() like this: ...
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1 answer
4 views

rostipic echo doesn't work because of a md5sum problem

Hi, I am playing a bag file and I typed rostopic echo /nav_status to see the actual messages but this error message appears. What's going on? I saw other similar questions but I don't understand them. ...
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1 answer
30 views

Reading data from Topic

I am using a GPS plugin on my model. I know it works as I have tested by using rostopic echo gps_out and it continually outputs data in the NavSatFix form. I am ...
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1 answer
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Way to modify messages in rostopic without tweaking stuffs in ros driver

This is an example sensor message from my robot topic (/base_imu/data): ...
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2 answers
3 views

Additional topics in ROS kinetic

I use the rostopic command on my ROS and get the following output: had@had-HP-Pavilion-Laptop-15-cs0xxx:~$ rostopic list /rosout /rosout_agg I'm looking at a tutorial and they also use "...
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Unable to publish varying list of PoseStamped. gives AttributeError: 'NoneType' object has no attribute 'secs'

I have created Path_arr.msg as mentioned, string frame_id geometry_msgs/PoseStamped[] poses And I want to publish next 5 states of robot that should be subscribed ...
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1 answer
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The loop_rate() for my node doesn't change the publish frequency

Hi to all, I'm having problems with the loop_rate() function for my node. I set it at 10hz and then I publish some topics in the while() loop but when I rostopic ...
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1 answer
16 views

Is it possible to increase the publishing rate of a topic inside a launch file?

This is my situation, I am subscribing to a topic which publishes messages at a rate of 5 Hz and I want to increase the rate to 100 Hz. A way to achieve that, is creating a node and republish the ...
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1 answer
10 views

roslaunch rostopic pub file find package

How do I publish a message from a file, found with rospack find, using rostopic pub -f from a launch file? ...
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1 answer
21 views

Error when execute 'ros2 topic echo /hello_ros2 ros1_msgs/MyMsg'

The ros1_msgs/MyMsg is my custom message type, The package directory path is ~/ros1_install/src/ros1_msgs. So I open a terminal, then source the relevant package path to environment by this order: <...
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1 answer
2 views

Scaling data in a topic?

Let's say I have a node (that I didn't write) publishing an Int32 value data between 0 and 1. Is it possible to scale data so it'...
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1 answer
16 views

Problems with network setup involving Sawyer robot arms

I was working on a Sawyer robot arm (specifically, two of them plugged into the same router, but I'm just trying to get one started now). The cables got unplugged and then replugged, but the settings ...
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1 answer
7 views

How to get the actual coordinate for all of the joint?

Hi. I'm new to ROS Indigo. Is regarding the actual joint states, I have tried the rostopic echo /joint_states and /tf, but it seems like the joint_states and tf are keep on going non stop. May I know ...
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1 answer
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hokuyo subscriber callback delay?

Hi! I am trying to subscribe to a laser scan of the hokuyo_node. (UTM-30LX) I have checked that the rostopic(/scan) satisfied 40Hz. $rostopic hz /scan However, msg(/scan) callback is not satisfied ...
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1 answer
7 views

LiDAR does not appear in rostopic list?

Hello, I'm working on Jackal from Clearpath. The robot came with indigo and after a while, I re-imaged it. Now everything is working fine except LiDAR. When I run ...
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2 answers
96 views

check if topic is being published to without subscribing

In our project we want to write a node to check sensor nodes for possible errors. One of the checked criterion is, if the topics of the node are actually published and not just have publisher. Is it ...
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1 answer
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Subscriber to array type overwriting data from different publishers!

Hi, I have been witnessing some bizarre behaviour with my very simple node. I have a custom message that contains uint8[] type (it's 8 elements long). I have a ...
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1 answer
11 views

Why no cmd_vel topic during ROS + Gazebo Turtlebot Simulation?

I have been having a very difficult time trying to understand why my system does not have the cmd_vel topic. I am trying to get a ROS system running with Gazebo so that I can work through tutorials ...
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1 answer
4 views

Rostopic pub from master (one laptop) to nodes (other laptop)

Hello, I have the following configuration: laptop 1 that is the master (it runs "roscore") - it doesn't have the package or messages used by nodes laptop 2 that has two running nodes I ...
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1 answer
58 views

How to publish a dictionary with other dictionary inside in a topic?

Hi all, I'm trying to publish in a topic a dictionary with other dictionary inside so other ROS node is able to access to that information, but I do not know how can I do it. Anyone has any idea? ...
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1 answer
17 views

How to check size of a topic on multi device ROS Communication

Hello, experts. I am trying to ROS communicate with multi device. There is two PC. First one have a camera sensor, it have publish topics by 30 fps. Second one have be connected to another by 1Gb ...
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1 answer
7 views

Get raw network data of a ros topic

Hey guys, I try to get the raw data of a topic in ros for some days now. My Problem is, that I receive a complex Message Type from a topic and I have to serialize its data to a <uint8_t>vector ...
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1 answer
41 views

$ rostopic list ERROR: Unable to communicate with master!

I am trying to calibrate a Logitic 920 HD 1080p camera in Ubuntu 16.04. I have installed ros kinetik. I am not sure if this tutorial is the correct link but I get this error: http://wiki.ros.org/...
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1 answer
57 views

How to have topics publish and subscribe both ways between host and docker container?

I have roscore running in docker. I have a bunch of topics, some are started by nodes inside the docker container, some are outside of the container, on host. I need some of these topics to subscribe ...
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1 answer
5 views

how can we create a node publishing a random data using a class and without using a callback function

I want to create a publisher node without using a callback function as the title explains. Have you guys any suggestions? Originally posted by samo on ROS Answers with karma: 11 on 2018-07-19 Post ...
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1 answer
17 views

Cannot connect to Jackal clear path from my laptop

I have successfully connected the jackal robot to a wifi network by ssh ing to the jackal through an ethernet cable, so my robot has a working internet connection. When I follow the steps outlined in ...
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1 answer
2 views

Cannot execute rostopic list -v correctly

Hi, I am a beginner to ROS, please see below information about my environment: ROS version: melodic Platform: Ubuntu 18 Environment Variables (output of env | grep ROS) i source the setup.bash file ...
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1 answer
6 views

rostopic no longer work

I am working with ubuntu 14.04 indigo. I was downloading a python program and installed a few dependences like python3-pandas, python3-yaml, python3-rospkg. Now, it ...
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1 answer
2 views

Fetch robot, joint_state topic sometimes contains all joints, sometimes doesn't

I am programming with the Fetch robot (the physical one, not Gazebo simulation). I use my laptop with the following settings: Macbook Pro Late 2013 edition Ubuntu 14.04 installed as sole operating ...
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0 votes
1 answer
30 views

No rostopic response when run in docker container

When I run rostopic hz <topic-name> inside a docker container to get the publishing rate of a topic via the containers logs I don't get any output. (If I echo ...
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1 answer
6 views

Can python subscribe nodelet topic?

I'm new in ROS and I understand that nodelet is using ROS c++ interface. Currently, I am using a library which can publish nodelet topic. Should I have to write ...
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0 votes
1 answer
5 views

how to echo custom-defined message remotely?

There are two machines, A and B, connected via Ethernet cable, and their connections are established. One of the ROS package implemented at the machine A has custom messages, and I would like it to be ...
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1 answer
19 views

How to make a ROS topic?

How do I make a ROS topic. I want to make a ROS topic (Either a subscriber or a publisher) which I can either write to or read from. For example: how ROS programs have topics I can subscribe to or ...
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2 answers
30 views

republishing a Gazebo topic to a ROS topic

Hi, I'm currently working on trying to get a gazebo topic into the ROS topic list so I can access it through the matlab interface with ROS. Right now I managed to create a subscriber to the gazebo ...
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1 answer
1 view

Export topic from bag at different rate

Hi to all, i have recorded several bag files which contain different topics recorded at different rates. For example: ...
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1 answer
13 views

Can't use rqt_plot with some topics

Hi to all, I'm not able to use rqt_plot with some topics (I'm using ROS Indigo). I this it's because I can't find the correct field name and so I'm not able to ...
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1 answer
23 views

Write/Improve a ROS node to publish encoder data

Hi to all, I'm using two incremental encoders (SICK DFS60B) on my skid steering robot. A full wheel turn on each side generates about 2241114 pulses. I wrote a ROS node in C language in order to ...
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1 answer
30 views

Unable to communicate with master with roscore running

Hi, I am trying to subscribe to a node I launched on a raspberry pi on my laptop. I am able to SSH into the raspberry pi to launch the node (the problem is not that roscore isn't running because it is)...
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0 votes
1 answer
7 views

Publish on a Topic for a certain time

Hi, I would like to know if it is possible to publish on a topic for a certain time (fixed before publishing). For example, I want to publish a linear velocity (geometry_msgs/Twist Message) for 3 ...
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