Is it possible to test XRCE DDS on real HW?

Karthik_B · April 3, 2024, 8:56am

Thank you for the reply @rhys . Also Micro_ros should be installed in the flight controller right?

rhys · April 3, 2024, 12:01pm

No, we are not using micro-ROS, but DDS eProsima micro XRCE DDS directly (they are different). We use the micro-ROS agent on the PC / companion computer to connect the DDS comms from the flight controller to the ROS 2 network.

mefrankli · May 27, 2024, 2:16pm

I have tried to connect Cube Orange Plus with ros2
in terminal I can see that dds connection is working but I’m not able to see any topics in ROS2
Am I missing something? I have tried it with running mavproxy but still no luck!

If anybody got this working please help

rfriedman · May 27, 2024, 11:47pm

If all the topics match, but no nodes or topics appear in the ROS 2 CLI, check you have ROS_DOMAIN_ID set to “”.

mefrankli · May 28, 2024, 10:42am

Hi @rfriedman
current ROS_DOMAIN_ID set to 22
Here is data from my bashrc file:

NB: Using orange cube_plus+ connected to the laptop using a USB cable

source /opt/ros/humble/setup.bash
export ROS_DOMAIN_ID=22
export ROS_LOCALHOST_ONLY=1
export PATH=$PATH:~/Micro-XRCE-DDS-Gen/scripts
export GZ_VERSION=garden
source /home/ubuntu/ardupilot/Tools/completion/completion.bash
export PATH=$PATH:~/.local/bin
export PATH=$PATH:/usr/local/lib/python3.10/dist-packages/MAVProxy

rhys · May 28, 2024, 2:02pm

Try export ROS_DOMAIN_ID=0. Currently this choice is hardcoded in the AP_DDS library. Can you also post the output from the micro_ros_agent when run with the verbose flag (-v6).

mefrankli · May 29, 2024, 5:25am

Hi, I got this working after setting ROS_DOMAIN_ID=0 and disconnecting from the internet while running.

:~/ros2_ws$ ros2 topic list
/ap/battery/battery0
/ap/clock
/ap/cmd_gps_pose
/ap/cmd_vel
/ap/geopose/filtered
/ap/gps_global_origin/filtered
/ap/imu/experimental/data
/ap/joy
/ap/navsat/navsat0
/ap/pose/filtered
/ap/tf
/ap/tf_static
/ap/time
/ap/twist/filtered
/parameter_events
/rosout

mefrankli · June 26, 2024, 1:39pm

Hi Im trying the same in jetson orin nano with JP6.
But when i try to run I’m encountering this error anyone know why this is happening ?
it says dds_xrce_profile.xml’ file is missing !!!
But the same work perfectly in my Ubuntu 22.04

/ros2_ws/src/ardupilot/libraries/AP_DDS$ ros2 run micro_ros_agent micro_ros_agent serial --baudrate 115200 --dev /dev/serial/by-id/usb-CubePilot_CubeOrange+_1A0032000D51323031393637-if02 --refs dds_xrce_profile.xml -v6
Error: reference file ‘dds_xrce_profile.xml’ does not exist!
Usage: ‘micro_ros_agent <udp4|udp6|tcp4|tpc6|canfd|serial|multiserial|pseudoterminal> <>’
For a more detailed description about all the available arguments, please execute the agent with ‘-h/–help’ option.

My bashrc file for reference
source /opt/ros/humble/setup.bash

export PATH=$PATH:/home/ceed/ros2_ws/Micro-XRCE-DDS-Gen/scripts
export PATH=$PATH:~/.local/bin
export PATH=$PATH:/usr/local/lib/python3.10/dist-packages/MAVProxy

export ROS_DOMAIN_ID=0
export ROS_LOCALHOST_ONLY=0

export GZ_VERSION=garden
source /home/ceed/ros2_ws/src/ardupilot/Tools/completion/completion.bash
export PATH=$PATH:~/.local/bin
export PATH=$PATH:/usr/local/lib/python3.10/dist-packages/MAVProxy

export PATH=“$PATH:$HOME/.local/bin”

when i manually added this dds_xrce_profile.xml
this error resolves but still communication between jetson and cube doesn’t happening!
Output:
:~/ros2_ws/src/ardupilot/libraries/AP_DDS$ ros2 run micro_ros_agent micro_ros_agent serial -b 115200 -r dds_xrce_profile.xml -D /dev/serial/by-id/usb-CubePilot_CubeOrange+_1A0032000D51323031393637-if00
[1719469514.466439] info | TermiosAgentLinux.cpp | init | running… | fd: 3
[1719469514.470243] info | Root.cpp | set_verbose_level | logger setup | verbose_level: 4

rhys · June 27, 2024, 10:25pm

The need for a refs file was removed from master in AP_DDS: replace ref interface with binary interface in uxr create entity methods by srmainwaring · Pull Request #27145 · ArduPilot/ardupilot · GitHub. It is still needed for the 4.5 release, but when running master drop the --refs dds_xrce_profile.xml option as the file has been removed.

mefrankli · July 3, 2024, 7:48am

And even with --refs dds_xrce_profile.xml` the ardupilot-cube need to disconnect and connect it back again to establish connection , is there any known workaround for that as-well?

FYI
When i rebuild all ros2_ws from scratch to get new updates
then the output is : -

I have tried running mavproxy.py in other terminal but still not creating topics

But when I try checking stream using command , I can see the data flowing …

~/Desktop/ros2_ws/src/ardupilot/libraries/AP_DDS$ python3 -m serial.tools.miniterm /dev/serial/by-id/usb-CubePilot_CubeOrange+_1A0032000D51323031393637-if00 115200 --echo --encoding hexlify— Miniterm on /dev/serial/by-id/usb-CubePilot_CubeOrange+_1A0032000D51323031393637-if00 115200,8,N,1 —
— Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H —
01 A7 68 88 FD 19 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 05 61 4B FD 14 00 00 EE 01 01 F1 00 00 44 BA 1A 10 00 00 00 00 C6 F2 42 3C 0F 89 D7 3C 5F 7A A9 3C EC 84 FD 29 00 00 EF 01 01 93 00 00 FF FF FF FF FF FF FF FF FF 7F EA 00 FF FF FF FF FF FF FF FF FF C9 FD 1C 00 00 F1 01 01 A3 00 00 FE 8C C6 B8 6D 7F 6F 35 C4 66 B3 B9 00 00 00 00 00 00 00 00 F6 5E 1A 3A 10 3F 89 3C 61 15 FD 0C 00 00 F2 01 01 B2 00 00 F3 AB 46 40 C6 EB 50 BC A1 D8 8C BE 07 D3 FD 1C 00 00 F3 01 01 1E 00 00 6E 20 04 00 DB 72 46 40 2A D9 C4 BA E3 E2 8B BE 77 B3 AC B8 A4 38 7C B8 7A CB D7 B9 AE FE FD 1C 00 00 F4 01 01 21 00 00 6E 20 04 00 00 00 00 00 00 00 00 00 22 06 00 00 28 06 00 00 00 00 00 00 00 00 83 86 FE 19 FD 12 00 00 F5 01 01 4A 00 00 00 00 00 00 00 00 00 00 C2 F5 C8 3F 01 AE 92 3F 58 01 96 F3 FD 1F 00 00 F6 01 01 01 00 00 0F DC 30 13 0F 00 20 12 0F 81 10 03 46 00 E6 00 …

rhys · July 3, 2024, 2:09pm

@mefrankli, I’ve added a note describing how to run a HW test on a laptop using a CP2102 USB-to-UART bridge to provide a second USB connection: Testing PPP and DDS on a desktop or laptop