Force subscriber to process messages in the right order
I have a single publisher that publishes messages at high frequency (1800 Hz), and a subscriber in another node. I realized that the messages are not always processed sequentially. I verified this by...
View ArticleMavros move drone, no gps
Here am I again... I have been trying and trying but I can't seem to get the hang of it... I'm trying to move a drone to a certain location. I have the distances, which get updated whit a frequency of...
View ArticleROS2 ament overlay issue with messages
I'm working on adding array parameter support for ROS2, and am having trouble with ament. I've added new types and values...
View ArticleImport variables from a message
Hello, In my code I would like to get a variable from my message and use this in my main. Whenever I run this code "x" is said to be 0.00. This should be a different number. In my message I declare my...
View ArticleQuestion re ACML_demo rosout messages
Hi All, I am fairly new to ROS, so forgive a rookie question. When I run amcl_demo.launch and view the output, I can see info such as "goal reached" and "got new plan", and I would like to publish...
View Articlemap does not show up on RVIZ while using hector_slam
Hello everyone, i am using RPLIDAR A1 and hector_slam but so for there is no luck, RVIZ will start with nothing and no map in it. Here is the details: from this topic...
View ArticleIs there a possibility in ROS to check that in the other machine messages...
Hi, Is there a possibility in ROS to check that in the other machine messages publish in the topic without direct transfer of messages between the machines? I would like to transfer between machines...
View ArticleIs there any way to parse C structures to ROS messages?
I'm looking for a way to convert a C structure to a ROS message. Does has any ideas how to do it? Does ROS provide some tools to do that? Or should I write parser on my own?
View ArticleCannot open rosbags with multiarrays.
- Distro: kinetic - OS: Ubuntu 16.04 - Program: Matlab and python Hello, I've encountered this problem in matlab R2018a (it works fine in R2017b) and in python. When trying to open a rosbag with any of...
View ArticleGet information about topic message at runtime
I am trying to build an interface that universally bridges ROS topics to another system. I am importing the message type at runtime: importcom = ( # import type "from " + topic_class + ".msg import " +...
View ArticleHow to collect messages from all topics and put them into a csv file?
Hello everyone! I have a .bag file with recorded messages from 4 different sensors (2xIMU, 2xINEMO), which have been worked simultaneously. I need to collect all messages from all sensors' topics and...
View ArticleProblem regarding header files in Arduino
When I run Arduino IDE using the command "arduino" and compile it, I get the error that "sabertooth.h" and "kangaroo.h " doesn't exist, when I open it using the command "sudo arduino" I get the error...
View Articlerospy ColorRGBA array messages changing all vectors
So I'm trying to make certain LED's change color on certain events, I wrote a small program to test these changes import rospy from ledtracker.msg import ColorArray from std_msgs.msg import ColorRGBA...
View ArticleWhat is the difference between a topic and a message?
A very newbie question for sure, but I'm having a little trouble distinguishing between topics and messages. I understand that topics are the named "channels" published and subscribed by nodes and...
View ArticleWhere do I publish a robot's status?
I would like to trigger a LED or another indicator when ROS is running and or a specific package is ready. Would I do this as a service or a message? How would I track it when its not ready any...
View ArticleSubscriber not receiving messages even though publisher is continuously...
Hey! Had a question I needed your clarification with! I have a publisher that continuously publishes onto a topic, and I have a subscriber node that is defined as a part of the class. For some reason,...
View Articleros::desrialize messages
Hello. I'm building a system based on ros messages (not using ros message transferring system, only its messages). I'm using python zmq system to send ros messages, and cpp zmq to receive it. On the...
View ArticleLooking for existing Electromyograph EMG/EEG, or voltage messages
I am in the process of implementing a ROSBag writer for an electromyograh device. Before implementing my own messages, I would like to know if such messages already exist. Basically I al looking for...
View ArticleROS2 Custom Messages Not Found
While trying to run my python script, I get `ModuleNotFoundError: No module named 'lightring_msgs'`. I know the message types are being generated; the package files are in the install directory. Why...
View ArticleMessage for publishing roll, pitch, yaw without converting to quaternion
Hi there, I have been looking for a way to publish roll, pitch, yaw angles without change them to quaternions but I didn't find that kind of message after googling for a while. I know I can write my...
View ArticleUnderstanding messages MDSum
I am trying to understand how the MD5Sum of the messages is being calculated following this [link](http://wiki.ros.org/ROS/Technical%20Overview#Message_serialization_and_msg_MD5_sums) So far, I...
View Articleros2 rti dds cross communications example?
Does anyone know of an example of an RTI connext DDS node reading/writing with a ROS2 node? I have been using RTI connext for the last few years and am jumping back into ROS, via ROS2. However, i am at...
View Articlefinding the right action name and package names to import for smach
hi, i am creating a state machine which calls multiple actions and services but having trouble finding the right package/service names to import. the examples on tutorial pages are not helping much on...
View ArticleSubscribing multiple topics with different rate
Hey there, I´m currently new at ROS but made yet all the beginner tutorials at the ROS homepage. First I implemented a simple publisher and subscriber and it worked. Now I want to create something like...
View ArticleMessages aren't built
I've downloaded a ROS package and I would like to use its messages in my program, however, for some weird reason the messages aren't built and thus I get an error. My package.xml has this:...
View ArticleWhat is the correct (standard) way of using sensor_msgs/TimeReference?
I am writing a node that indirectly interfaces with a GPS receiver. I want to match the interface of the [NMEA Navsat Driver](http://wiki.ros.org/nmea_navsat_driver), for convenience, but I don't...
View ArticleIn publish raise ROSSerializationException(str(e))
In my package that I created, there are 3 nodes currently. I also generate a custom message which is "AnchorScan". First node does some stuff and only publishes from `/IPS` topic. Second node...
View ArticleHow to provide variance field in sensor_msgs/FluidPressure messages?
I'm writing a ROS driver for a pressure sensor and while I really only need to publish the 'pressure' field, I'd like to also fill out the other field which is 'variance' for the sake of completeness....
View ArticleTeraranger tower evo doesnt publish the data from each of its sensors.I've...
enter code here[ERROR] [1560244035.890227391]: Client [/range_ahead] wants topic /ranges to have datatype/md5sum [sensor_msgs/Range/c005c34273dc426c67a020a87bc24148], but our version has...
View ArticleImportError: No module named msg - standard ROS message
Hi, I am trying to use `geodesy` package https://github.com/ros-geographic-info/geographic_info I have installed the stack using `apt-get`. I can include the messages in `.cpp` files however in Python...
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