Nexus8's profile - activity

Cross compiling? Hello friends, I am working with Humble on a raspberry Pi. The system will be in charge of the low-lev

Cross compiling? Hello friends, I am working with Humble on a raspberry Pi. The system will be in charge of the low-lev

Hi,

If you plan to use WiFi you will have to make sure that you can ping all components on the network. In other words, properly set up your network. I would say there must be a set up guide for the Arduino/shield on the web to do so.

Then, start sending UDP packages (or the protocol that suits your application) from your Arduino to one node in ROS.

Cheers

North-East-Down is a right handed frame! No doubt about it. The image you shared from DJI displays the drone from its back x axis pointing towards the front. X CROSS Y = Z, so it is a right handed frame. Use a rotation to convert between frames.

Choosing a subgroup from the group of 15 quadcopters is software/addressing related. That goes beyond of what launch files can do. On launch files you can define addresses and names, you can make sure that all names and addresses are different. You can comment out nodes/quadcotpers not required.

Oh! Good! I was about to point out that your are asking for a left to right handed axis transformation. Ok, be careful with your reference frames. I would suggest to change your perspective to:

x: North y: East z: Down

Georeferenced systems used that reference frame (drones, rovers, planes).

Yes sir, I did!

## System dependencies are found with CMake's conventions
## GStreamer 1.0 package required
find_package(PkgConfig)

macro(find_gstreamer_component prefix pkg lib)
  pkg_check_modules(PC_${prefix} REQUIRED ${pkg})
  find_library(${prefix}_LIBRARIES NAMES ${lib} HINTS ${PC_${prefix}_LIBRARY_DIRS} ${PC_${prefix}_LIBDIR})
  list(APPEND gstreamer_INCLUDE_DIRS ${PC_${prefix}_INCLUDE_DIRS})
  list(APPEND gstreamer_LIBRARIES ${${prefix}_LIBRARIES})
  mark_as_advanced(${prefix}_LIBRARIES gstreamer_LIBRARIES gstreamer_INCLUDE_DIRS)
endmacro()

find_gstreamer_component(gst      gstreamer-1.0       gstreamer-1.0)
find_gstreamer_component(gstbase  gstreamer-base-1.0  gstbase-1.0)
find_gstreamer_component(gstapp   gstreamer-app-1.0   gstapp-1.0)
find_gstreamer_component(gstvideo gstreamer-video-1.0 gstvideo-1.0)

I'm terribly sorry not to give credit to the authors, but I don't remember where I find a ROS package that also required Gstreamer 1.0.

cheers.

What if you try creating the image message doubling the width and then do some programming to store one 16 bit pixel in two pixels, send the image message, and when you receive the image message on your subscriber node do exactly the inverse to create an OpenCV compatible image?

Just an idea.... Cheers...

How are you getting this readings? Are you accessing the IMU using a UART on your computer, creating the message and the publishing what you get?

In any case, something is wrong with the code you are using, the quaternion should indicate a vector of norm equal to one. All elements are equal to zero on what you shared.

cheers...

You can build a rotation matrix or a quaternion that represents the change in orientation from one reference frame to the other reference frame. Then all you do is rotate your vector [x,y,z] with the quaternion or matrix.

Cheers

It is possible. Check the roslaunch tips for large projects.

What you need is to create a node that uses image transport and camera info manager. The image transport is the standard way to publish images in ROS and the second shares the calibrated camera information. I imagine that you will have to somehow broadcast the images from your phonte to the pc running ROS and then your node should receive and publish the video feed you receive.

Cheers...

Hello,

I'm trying to get running a UDP Camera with the help of Gstreamer on ROS.

I carefully went through the tutorials of Gstreamer and I managed to get a functional C program to get the video feed. I mean, I know the pipeline is correct. I built this program with cmake and make, it works with gstreamer 1.0 and it depays/decodes RTP H264 video. When I run this program I can confirm with: gst_version_string() that the version of Gstreamer is >1.0.

The problem arises when I try to do this on ROS. I added the exact same lines on the cmakeslists.txt of my package to find and link Gstreamer 1.0, but when I run my node I get gstreamer version is 0.10. The lines that share my cmakelists.txt on the pure C and Ros Package are:

find_package(PkgConfig)
pkg_check_modules(GSTREAMER REQUIRED gstreamer-1.0)
pkg_check_modules(GST_APP REQUIRED gstreamer-app-1.0)

So, my best guess is that I have to change something on my cmakeslist.txt or some catkin_make related setting. Do you know how can I make this work?

Any help would be greatly appreciated.

Hello,

I'm trying to get running a UDP Camera with the help of Gstreamer on ROS.

I carefully went through the tutorials of Gstreamer and I managed to get a functional C program to get the video feed. I mean, I know the pipeline is correct. I built this program with cmake and make, it works with gstreamer 1.0 and it depays/decodes RTP H264 video. When I run this program I can confirm with: gst_version_string() that the version of Gstreamer is >1.0.

The problem arises when I try to do this on ROS. I added the exact same lines on the cmakeslists.txt of my package to find and link Gstreamer 1.0, but when I run my node I get gstreamer version is 0.10. The lines that share my cmakelists.txt on the pure C and Ros Package are:

find_package(PkgConfig)
pkg_check_modules(GSTREAMER REQUIRED gstreamer-1.0)
pkg_check_modules(GST_APP REQUIRED gstreamer-app-1.0)

So, my best guess is that I have to change something on my cmakeslist.txt or some catkin_make related setting. Do you know how can I make this work?

Any help would be greatly appreciated.

DSG

ps. I require Gstreamer 1.0 because 0.1 is now not recommended. Ubuntu recently moved to libav which works great with 1.0 and lastly, the components on the pipeline I'm using to decode H264 are only available on 1.0.