Publish to topic from file
Hello, I am quite new to ROS. I have a logfile (format: .pcapng) and I want to write a node which receives the logged udp-packets (as a simulation; later, the node should receive these packets from a...
View Article/joint_states topic and publish rate
I want to read the joint states of a robot from the `/joint_states` topic, preferably at 1kHz. The problem is that when I increase the publishing rate X of the joint controller above 100Hz, a...
View ArticlePusblishing to topic problem (Mavros)
I'm trying to push to the override RC for mavros. I checked the message type first rostopic type mavros/rc/override giving mavros_msgs/OverrideRCIn I then check the parameters for this message type...
View ArticleHow to subscribe to a topic, while publishing to another
Hey guys, I want to write a basic controller for a quadrotor. For a target_position it should take the current_position from a simulated quadrotor, calculate an error between the two and send the...
View Articlemodify turtle_teleop_key to control mavros
HI I wonder make a node to send control information to [mavros](http://wiki.ros.org/mavros). So I modify the [teleop_turtle_key.cpp](https://github.com/ros/ros_tutorials/tree/jade-devel/turtlesim)...
View Articlepublish multiple data on one topic
Hello, Is it possible to publish multiple data i.e angle for servo1 and angle for servo2 on one topic ? If yes, please show me answer how to do it. Thanks in advance. --- Edit: Thank you sir for your...
View Articleadvertise() function parameter for vector type
I'd like to publish a vector (cpp) in my publisher, and I do not want to create my own message. Is there already a built-in type for it? What I mean is to replace `"std_msgs::Float64"` part below:...
View Articlepublish message not maintain(bool type) in the program
When I publish message, callback function from subscriber works well. However when I use bool type of valuable, the valuable disappear in the program. For example I publish 1.0 and bool type valuable...
View Articlepublish c structs
Hey guys, I'm searching for a way to publish my own c struct. In my code I use a struct like: struct test { int a; int b; int c; float d; } ; and I want a message that uses two integers and one "test"....
View ArticlePublish to Topics of different node [Solved]
Dear All, I have a silly question. is there a way to publish to topics of different node using c++ methods? I mean like we are subscribing to topics of different nodes, is there a way to publish to...
View ArticleRosbridge_server - formatting header with JSON
I have a simple python script that I can't upload because I don't have 5 points. My script "advertise" sensor_msgs/Joy and then tries to send one with a header. The same code works for the json string...
View ArticleStage ros velocity publish rate
Hi, I am working with some simulation issues in Stage ROS. I want to reduce the publish rate of each robot's pose topic, e.g. robot_0/base_pose_ground_truth, robot_1/base_pose_ground_truth, etc. due...
View ArticleHow to publish a 2 dimensional array of known values
Hello, I'm stuck at my program to publish a 2 dimensional array. The array kinda looks like this: int deptharray[4][5] = { {0, 0, 0, 0}, {0, average11, average21, average31, average41}, {0, average12,...
View ArticleHow can i make communication between two nodes(Python)
Hi... I have a problem with rospy. I want to create two nodes that communicate with each other. The problem is that the communication starts only when node1 and node2 send information on the channel...
View ArticleIs it possible to publish/subscribe as root?
Hello smart people, I have made a ROS node that makes use of an FTDI library that requires that I run the executable as root to have access to the usb device that the node reads data from. The trouble...
View Articlepublish numpy matrix to topic
Hello together, I would like to publish a 10x10x10 numpy-Matrix in one publishing step. Therefore I would like to know how I can declare the `numpy.ndarray` as a message type like matrix.msg: >...
View ArticleHow do Publisher/Subscriber Message Queues Work?
Hi all, I can't seem to find any documentation on this, but it I want to understand more deeply how messaging queues work. My understanding is that each node has its own publisher and subscriber...
View ArticleNameError: global name 'NAME' is not defined
hello, I'm trying to publish data of my GPS but it appears this error NameError: global name 'hora' is not defined Anybody help me please :) My code is this: #!/usr/bin/env python import rospy import...
View ArticleReducing the publishing rate of a topic from RosLaunch
Hi there, I have a custom-built robot which I am trying to control with move_it. I have written the urdf and generated the srdf using the move_it setup assistant. All the topics from my URDF are being...
View ArticleSubsribe and publish conversion problem
I'm trying to write an own Subscribe and Publisk node. I would like ti subscribe to the joystick and publish to my motors. For the publish i create with a launchfile to topics, I use the...
View Article