Companion pc is not able to communicate using Discovery Server

[Onionsoupe]

Robot Model

Turtlebot4 Lite

ROS distro

Humble

Networking Configuration

Discovery Server

OS

Ubuntu 22.04

Built from source or installed?

Installed

Package version

ros-humble-turtlebot4-bringup: 1.0.3-1jammy.20250915.224200 (installed via apt)

Type of issue

Networking

Expected behaviour

When running ros2 topic list on my PC, I expect to see all TurtleBot 4 topics being published by the robot (Pi), such as /cmd_vel, /scan, /imu, /joint_states, etc., similar to the output I see when running ros2 topic list directly on the Pi.

Actual behaviour

Currently, the PC only shows:

/parameter_events
/rosout

which indicates that it is not discovering the robot’s topics over the network.

Error messages

Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.
2025-11-26 16:15:39.332 [XMLPARSER Error] Invalid element found into 'builtinAttributesType'. Name: use_SIMPLE_EndpointDiscoveryProtocol -> Function getXMLBuiltinAttributes
2025-11-26 16:15:39.332 [XMLPARSER Error] Error parsing participant profile -> Function parseXMLParticipantProf
2025-11-26 16:15:39.332 [XMLPARSER Error] Error parsing profile's tag participant -> Function parseProfiles
2025-11-26 16:15:39.332 [XMLPARSER Error] Error parsing '/home/turtlebot-pc/.ros/fastdds.xml' -> Function loadXMLFile
This happens when Rviz is run.

To Reproduce

Connect the pi using turtlebot-setup to a 5Ghz wifi. Connect the pc to the same router.

On the Pi, verify ROS 2 topics:

ros2 topic list

Expected output includes /cmd_vel, /scan, /imu, /joint_states, etc.

On PC running Ubuntu and ROS 2 Humble, verify ROS 2 topics:

ros2 topic list

Only /parameter_events and /rosout are listed.

Confirm network connectivity between PC and Pi:

ping <Pi_IP>

Response is successful.

Check that Fast DDS XML configuration files are present and set on both PC and Pi.

Attempt to run ROS 2 nodes or bringup on the PC to interact with the TurtleBot 4 robot.

Other notes

<participant profile_name="turtlebot4_pc" is_default_profile="true">
  <rtps>
    <builtin>
      <use_SIMPLE_EndpointDiscoveryProtocol>true</use_SIMPLE_EndpointDiscoveryProtocol>
      <use_STATIC_EndpointDiscoveryProtocol>false</use_STATIC_EndpointDiscoveryProtocol>
      <domainId>0</domainId>
    </builtin>
    <userTransports>
      <transport_id>udp_transport</transport_id>
    </userTransports>
    <transport_descriptors>
      <transport_descriptor>
        <transport_id>udp_transport</transport_id>
        <type>UDPv4</type>
        <interfaceWhiteList>
          <address><!-- PC Wi-Fi IP --></address> 
        </interfaceWhiteList>
      </transport_descriptor>
    </transport_descriptors>
  </rtps>
</participant>

[RustyCPR]

Hi there @Onionsoupe,
Sorry you’re running into concerns with your remote PC setup - happy to help.

1. Can you please confirm whether Ubuntu 22.04 with ROS 2 Humble is installed natively on your remote PC?

2. After that, were you able to complete the ROS 2 installation steps from the TurtleBot4 user manual? Reference: User PC Setup section.

3. Once ROS 2 is installed, you’ll also need the TurtleBot4 desktop tools: sudo apt update && sudo apt install ros-humble-turtlebot4-desktop

4. Next, can you double-check that you’ve sourced and exported the correct environment variables:

source /opt/ros/humble/setup.bash
export RMW_IMPLEMENTATION=rmw_fastrtps_cpp
export ROS_DOMAIN_ID=0
ros2 topic echo /ip

5. Please also try the following:

source /etc/turtlebot4_discovery/setup.bash
source ~/.bashrc
ros2 daemon stop ; ros2 daemon start
ros2 topic list

6. Could you share the full terminal output from these commands? That will help us narrow down what’s going on.

Thanks,
Rusty