diegomex's profile - activity

Hi Rabe, thank you for your answer. What I want to do is to publish the received "data" in a new topic... I supose that maybe this should be done inside the callback that received "data", but I really dont know. "Data" is only avalable inside the callback local context, not for the publisher. Cheers

Hi, I would like to make a listener/talker in python. I already looked at the tutorials. However, these examples implement two separated codes, a listener and a talker, and I would like to implement them on the same node:

1. Some external node (TalkerA) shouts some mesagges through a topic TopicA (NO PROBLEM, it's a simple talker).
2. A second node (ListenerTalker) subscribes to TopicA and shouts something in TopicB.

For example, TalkerA shouts "Hello", and ListenerTalker listens TopicA and shouts "HelloWorld"...

How can I do this? It's a simple question, but it's not clear for me. Cheers!

Hi dear ROS community!

I would like to learn how to use multiple RGB cameras with ROS in a single PC. I already know how to use a single camera with the gscam package, I can read the video stream in the /camera/image_raw topic.

However, I couldn't find any information about the use of multiple cameras with ROS (let's say 3). I would like to create a node for each camera ( e.g. /camera01/image_raw, /camera02/image_raw, etc.) and then process them separatedly. I don't know if this is possible using gscam.

In general, what is the proper way (good practice) to use multiple RGB cameras with ROS?

Thank you very much!

Hi dear ROS community!

I've started learning ROS a few months ago. Currently I'm trying to create my first launchfile that starts gscam and image_view packages to open a camera and visualize the video stream. I made a launch file, however, gscam and image_view cannot get connected. Gscam node is launching properly, but not the image_view one; it seems that it is not receiving the parameter. If I launch image_view manually ($rosrun image_view image_view image:=/camera/image_raw) everything works fine and I can visualize the video stream from my camera. How can I fix my launch file? Thank you!

    <launch>
<node pkg="gscam" type="gscam" name="gscam01">
<env name="GSCAM_CONFIG" value="v4l2src device=/dev/video0 ! video/x-raw-rgb,framerate=30/1 ! ffmpegcolorspace" />
</node>

<node pkg="image_view" type="image_view" name="image_view01">
<param name="image" type="string" value="/camera/image_raw" />
</node>

</launch>

SOLUTION:

launch>
<node pkg="gscam" type="gscam" name="gscam01">
<env name="GSCAM_CONFIG" value="v4l2src device=/dev/video0 ! video/x-raw-rgb,framerate=30/1 ! ffmpegcolorspace" />
</node>

<node pkg="image_view" type="image_view" name="image_view01">
<remap from="image" to="/camera/image_raw"/>
</node>

</launch>

Thank you very much, this worked perfectly!