topics not publishing

[sdobbelaere]

Hi, I'm struggling to get the topics list.

Please provide the following information:

• OS: Ubuntu 22.04
• ROS Distro: Humble
• Built from source or installed: installed via deb packages
• Package version:

• Package: ros-humble-turtlebot4-base

  Package: ros-humble-turtlebot4-base
  Status: install ok installed
  Priority: optional
  Section: misc
  Installed-Size: 479
  Maintainer: rkreinin <rkreinin@clearpathrobotics.com>
  Architecture: arm64
  Version: 1.0.1-1jammy.20230822.184857
  Depends: libc6 (>= 2.34), libgcc-s1 (>= 3.3.1), libgpiod2 (>= 1.1), libstdc++6 (>= 11), libgpiod-dev, ros-humble-irobot-create-msgs, ros-humble-rclcpp, ros-humble-rclcpp-action, ros-humble-rcutils, ros-humble-sensor-msgs, ros-humble-std-msgs, ros-humble-turtlebot4-msgs, ros-humble-turtlebot4-node, ros-humble-ros-workspace
  Description: Turtlebot4 Base Node

  • Package pc: ros-humble-turtlebot-desktop

    Package: ros-humble-turtlebot4-desktop
    Status: install ok installed
    Priority: optional
    Section: misc
    Installed-Size: 41
    Maintainer: rkreinin <rkreinin@clearpathrobotics.com>
    Architecture: arm64
    Version: 1.0.0-1jammy.20230814.180152
    Depends: ros-humble-turtlebot4-viz, ros-humble-ros-workspace
    Description: Turtlebot4 Desktop Metapackage

  Expected behaviour $ ros2 topic echo /ip should show the ip like in the documentation.

  Actual behaviour

  $ ros2 topic echo /ip
  WARNING: topic [/ip] does not appear to be published yet
  Could not determine the type for the passed topic

To Reproduce Provide the steps to reproduce:

1. setup Wifi via ssh on turtlebot4
2. connect to wifi on create3
3. setup ros2-humble-turtlebot4-desktop
4. export the variables, and find the IP

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

Other notes Not sure what I'm missing. Would love some help :) Obviously I managed to get the IP from the screen on the turtlebot. But running ros2 topic list yields the same poor result:

/parameter_events
/rosout

In create3, I tried both with rmw_fastrtps_cpp and rmw_cyclonedds_cpp but the end result is the same.

files / data sources via bashrc:

$ cat /etc/turtlebot4/setup.bash 
source /opt/ros/humble/setup.bash
export ROS_DOMAIN_ID=0
export RMW_IMPLEMENTATION=rmw_fastrtps_cpp

export CYCLONEDDS_URI=/etc/turtlebot4/cyclonedds_pc.xml

$ cat /etc/turtlebot4/cyclonedds_pc.xml
<CycloneDDS>
    <Domain>
        <General>
            <DontRoute>true</DontRoute>
        </General>
    </Domain>
</CycloneDDS>

Thank you!

[sdobbelaere]

Ok. After trying out a number of variations on the discovery server approach I finally managed to get the topics by directly setting the robots as discovery server.

One more factory reset and re-flash later. I found the virtual machine I'm running on the laptop to be the problem. I'm on OSX, using Parallels - and the only way I got any topics to publish with the simple discovery setup was by manually setting a bridge on the wifi rather then on the default connection.

See screenshot for what worked.