ROS2 Offboard on Hardware

[REGATTE]

Hi,
I’ve been working with ROS2 for a while with PX4, have all my apps built w.r.t RTPS bridge and the SITL, is working fine. I want to test it on a real drone with a Pixhawk 5x(holybro) and Nvidia Jetson Nano. I understand that the guide to building a Hardware RTPS bridge is still not out from the developers.

I have tried building with the link below, but for some reason, the terminal crashes every time, without an error.

Building PX4-ROS2 bridge on hardware? (Pixhawk 4)

Hello all, I’ve had some success with SITL: creating ROS2 bridge listeners and advertisers through px4_sitl_rtps jmavsim. Thanks for your help there! Next, I’d like to have the ROS2 bridge code running on Pixhawk 4 hardware. I understand that I should upload a custom .px4 firmware file, but I’m not sure how to generate the correct one. I can make px4_fmu-v5_rtps and upload the resulting .px4 file; however, it doesn’t seem to capture the most up-to-date settings on the ROS2 bridge (e.g., the .y…

Anyone else has tried it??
What is the PX4 developer’s timeline to release it??

Thanks

[gugafelds]

Hey, did you manage to build it? I’m trying to do that too

[REGATTE]

(SOLVED) with reference to Micrortps_client does not receive uorb message and Unable to establish FastRTPS connection with pixhawk. #38 .

Plug Pixhawk 4 into companion computer via USB, make and upload the firmware from the PX4-Autopilot directory:

make px4_fmu-v5_rtps
make px4_fmu-v5_rtps upload

Enter the nsh> from ~/PX4-Autopilot/Tools$:

python3 mavlink_shell.py 

Start the micrortps_client over UART instead of UDP (which works for SITL):

nsh>  micrortps_client start -t UART

In a new terminal, source ROS2 and start the micrortps_agent over UART:

micrortps_agent start -t UART

In a new terminal, source ROS2 and echo the desired topic (or run the desired listener):

ros2 topic echo /fmu/vehicle_odometry/out

And the vehicle_odometry topic is printed for the Pixhawk 4 as desired. Hope this helps someone else stuck in the future!

Make sure it’s an UART connection instead of a UDP as it is a USB connection. If you’re using a pixhawk 5x, and connecting to the Companion Computer using the ETH port then use UDP.

You could later add a bash script to start PX4 at startup and automatically connect.