Publish a cmd_vel geometry msgs/twist from webserver over rosbridge to RVIZ
I am new to ROS and I am trying to publish a cmd_vel geometry_msgs/twist from my Webserver and visualize it in RVIZ, so that I can see the robot moving. I am running the ROS distro kinetic on a...
View ArticleScaling 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's between 0 and 10 instead of 0 and 1? Ideally, I'm wondering if...
View ArticleProblems 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...
View ArticlePublishing to /move_base_simple/goal
Hello All, This is a fairly straightforward question, however I have not been able to find it so far. Could someone please tell me the terminal command to publish move_base_simple/goal. I know it is...
View ArticleHow to get the actual position 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...
View ArticleCannot rostopic echo remote roscore
I have looked though most of the available online guides to rostopic echo a roscore running on a remote machine, but the standard suggestions are not helping I have configured the...
View ArticleHow data from one node send to another ?
I want to build an IOT-OS where one node can communicate with another. Ros sends data from one topic to another or from one node to another. I want the basic source code for understanding in depth...
View ArticleUsing ROS without Internet
Hello, I am building an outdoor robot and I will not be having internet connectivity. I was able to start and run the robot with internet connectivity. I changed the configuration to work without...
View Articlehokuyo 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...
View ArticleSending start command vs starting node.
I am planning to develop a system that has one master node. The master node handles different states and initiates other nodes. What is the best way to start slave nodes? 1. The master node starts a...
View ArticleConnection refused - docker to docker
Hi, I am trying to establish ros connection between 2 dockers. Details given below. 1. Lets consider I have **docker_1** and **docker_2**. 2. I am able to publish message from **docker_1** and...
View ArticleLiDAR is not appeared 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 `rostopic list` it doesn't show...
View Articlerostopic pub - {stamp:now} vs --rate
I would like publish a continuous flow messages on a topic from the terminal. In order to do that I use the --rate argument of the rostopic tool. However my message type contains a header field that I...
View ArticleDuplicate messages using `rostopic echo -b -p
Hello, I am using ROS Kinetic on Ubuntu 16.04. I am trying to save the rosbag mgss from topics into .csv files. When I used the command below, I see duplicate messages. `rostopic echo -b xxx.bag -p...
View ArticleTime synchronized callback doesn't seem to work
Hey there, I need your help again. My goal is to synchronize two topics: The first is a pointCloud2Topic which I want to synchronize with a message/topic that I wrote which revolves around the state...
View ArticleOctomap: No Map Recieved
Hello, I tried to follow various solutions and examples to launch my octomap in RVIZ. However, for some reason I still get no map recieved. I am aware that by just remapping the `"cloud_in"` to the...
View Articlechecking for published rostopic with data, without using terminal commands.
I am beginner novice working on a robotics project, I have written a series of rostopic list that publishes the data on the topic. But when I try launching many launch files, I wasn't able check for...
View Articlecheck 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...
View ArticleIs /clock being published?
Hi Guys, This question has been asked before, however I was not able to fix the issue by using the recommended solutions. Kindly help me in understanding the reason for this prompt and also the steps...
View ArticleSubscriber 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 subscriber that subscribes to a topic...
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