I just tried this real quick on VOXL1 and indeed there is an issue related to pty

on PC:

docker pull arm64v8/ros:rolling-ros-core docker image save arm64v8/ros:rolling-ros-core | gzip > rolling-ros-core-arm64v8.tar.gz adb push rolling-ros-core-arm64v8.tar.gz /data/

on VOXL1:

adb shell cd /data docker load < rolling-ros-core-arm64v8.tar.gz cd /home/root mkdir ros2 cd ros2 docker run -it --rm --privileged -v `pwd`:/home/user -w /home/user arm64v8/ros:rolling-ros-core #now inside docker container apt-get update apt install python3-colcon-common-extensions

then follow example to set up a demo project : https://roboticsbackend.com/ros2-launch-file-example/

run (inside docker container)
colcon build

Error:

stdout_descriptor, stdout = pty.openpty() File "/usr/lib/python3.10/pty.py", line 34, in openpty master_fd, slave_name = _open_terminal() File "/usr/lib/python3.10/pty.py", line 64, in _open_terminal raise OSError('out of pty devices') OSError: out of pty devices --- Failed <<< my_robot_bringup [0.21s, exited with code 1] Summary: 0 packages finished [3.72s] 1 package failed: my_robot_bringup 1 package had stderr output: my_robot_bringup out of pty device

After doing a quick search, cannot figure it out. It is probably related to very old docker version on VOXL1.. Not sure if anything can be done..

For a final wrap-up, we installed ROS2 Humble from Source on Voxl2 this fixed the communication issues.

We also noticed in Foxy if we we had the following set up on the same device

Publisher A -> (TOPIC A) Subscriber A (Which Publishes Topic B )

Topic A publishes 500Hz
Topic B publishes at 400Hz ish

In Humble,

Topic A publishes 500Hz
Topic B publishes at 500Hz

@Zachary-Lowell-0 Thanks Zach, this does answer. I have been used to ROS1/MAVROS where sending position targets was completely ignored unless in offboard mode so my node would typically blast setpoint_raw messages whether in offboard or not (in part to keep the option of switching to 'offboard' mode "alive").

I will proceed from now on in ROS2/MicroXRCE assuming I should constantly send offboard control mode messages, but send traj setpoints only when offboard mode is confirmed. I appreciate the clarification on why this is.

-Joe

@jacob-yaacubov , FYI, this fix will be in 1.2.0 release which is in testing now

@K-Stute here is the directory in voxl-dev px4-firmware: https://github.com/modalai/px4-firmware/blob/voxl-dev/src/modules/microdds_client/dds_topics.yaml

@Zachary-Lowell-0 @Moderator A really important question here is what if there are two drones publishing the same name FMU topics and you haven't set the domain id different for those drones for data sharing through your custom interfaces. PX4 ROS2 docs provide a way to change the namespace of the FMU topics to be published but MODAL AI docs mention no such thing? Is there a way to do that? As most of the starling systems are being used as a swarm platform this thing is really critical

@Zachary-Lowell-0 well it work now!
I found these lines on another thread of the forum:

sudo apt-get install voxl-ros2-foxy sudo apt-get install voxl-mpa-to-ros2 voxl-configure-mpa-to-ros2 source /opt/ros/foxy/mpa_to_ros2/install/setup.bash export ROS_HOME=/opt/foxy ros2 run voxl_mpa_to_ros2 voxl_mpa_to_ros2_node

And everything worked first time ! So please put these line directly on the documentation cause I lost so much time with this install !

@Prabhav-Gupta , you are welcome!

@Eric-Katzfey

I had backed up my ROS workspace using adb pull before flashing the drone and used adb push to reinstate my workspace on the drone. This unfortunately changed up the file permissions for the folders within the workspace.

I was able to fix this by deleting (using rm -rf) all folders within my ROS workspace except the src (which contains the packages I was working on) and building the packages again.

I was then faced with the other CMake error visible above -

@Prabhav-Gupta said in Unable to build ROS python workspace on the RB5 drone:

CMake Error at /home/root/python_ws/src/vision_opencv/cv_bridge/CMakeLists.txt:16 (find_package):
Could not find a package configuration file provided by "OpenCV" (requested
version 3) with any of the following names:

OpenCVConfig.cmake opencv-config.cmake

I fixed this by building opencv from source on the drone (following this - https://docs.opencv.org/4.x/d7/d9f/tutorial_linux_install.html)

After installing opencv, the catrkin build did not return any errors at the time. I do need to check whether my ROS Nodes are working as expected or not. Will update here once I do the same.

Thank you for your time!

@Denver-Bennett Were you able to find a solution to this? same issue on my end

@Denver-Bennett were you able to find a solution to this? same issue on our end

@Prabhav-Gupta You can just remap the topics coming out of the voxl_mpa_node, or remap the topics inside your ORBSLAM launch file. No need to mess with the source code.

Manual mode is not really representative of the ability to switch into offboard mode and send setpoints. You will need to be able to arm in position or hold mode first. If you do not have an rc controller then try to arm in hold mode. If you are not able to arm in either mode, then there is a preflight check fail somewhere that needs to be addressed first.

@tahawaru also since you are running an RB5 and not a voxl2, the most recent SDK you are running is 1.1.3 which might have dependencies in modal-pipe or modal-json that are not transferable to the newest dev branch of voxl-mpa-to-ros2 causing some form of error somewhere in the pipeline.

@brahim
@tom

Hi and sorry for the delayed response.

Main result : no response from the rb5
Comments: the offboard code example in cpp is running in Gazebo but I cannot get the drone to arm via ROS2 run px4_ros_com offboard_control.

This is the output from my terminal
~/ros2_ws$ ros2 run px4_ros_com offboard_control
Starting offboard control node...
[INFO] [1729601421.989530505] [offboard_control]: Arm command send

Notes: The offboard setting is "off" not "false" on the voxl-vision-hub.conf.

Do you have a recent tutorial on how to use ROS2 with the rb5?

Best wishes,

@Alex-Kushleyev

Please could you provide a simple example like arm() and disarm() or something similar to the offboard_control.cpp?

Best wishes,