MicroRTPS-Bridge not publishing ROS2 msgs

Hey everyone,
I’m currently trying to set up a micrortps-connection between a pixhawk 2 cube (black) flight controller (Hex Cube Black Flight Controller | PX4 User Guide) and a Raspberry Pi. The flight controller is running the default Firmware version of fmu_v3 where “micrortpsbridge”-module has been added to the cmake file. The Raspberry Pi is using a 20.04 Ubuntu LTS Server-Edition with ROS2-Foxy. As a connection I use the Tele2-Port of the pixhawk and a usb2uart ftdi-adapter (CP2102 USB UART Board(type A)).


To set up a connection between the Raspberry Pi and the flight controller I start the micrortps_client via Mavlink-Console from Q-GroundControll. I can also call a listener on any available topic there, which produces an output with a timestamp and some data.
Starting the micrortps_agent on the RPi I get notifications, that topics are published now.
Entering ros2 topic list in a new console on the RPi, none of the topics are listed.
Also starting the sensorCombined listener-node doesn’t give me any data, staying at the stage of “Starting listener node…”.
After closing the agent and the client, the notifications on both consoles show me an amount of messages “sent” and “received”. The Console-Code can be seen below.

This leaves me wondering, whether the micrortps-bridge is not working correctly (for this setup?) or messages are correctly exchanged but not published into ros2. Is there anything I’m missing about setting up the connection, that causes this problems or did anyone else already have this problem? Any help or advices are welcome, since I’m pretty new to ROS2.

Output from Pixhawk (Mavlink-Console from QGroundControll):

NuttShell (NSH) NuttX-10.1.0
nsh> micrortps_client start -d /dev/ttyS2 -b 921600 -t UART
INFO [micrortps_client] UART transport: device: /dev/ttyS2; baudrate: 921600; poll: 1ms; flow_control: No
nsh> listener sensor_accel

TOPIC: sensor_accel 3 instances

Instance 0:
timestamp: 465679695 (0.007060 seconds ago)
timestamp_sample: 465679429 (266 us before timestamp)
device_id: 2359330 (Type: 0x24, SPI:4 (0x00))
x: -0.2087
y: 0.2006
z: -9.9163
temperature: 50.0412
error_count: 0
clip_counter: [0, 0, 0]
samples: 5

Instance 1:
timestamp: 465728511 (0.000594 seconds ago)
timestamp_sample: 465728485 (26 us before timestamp)
device_id: 1114146 (Type: 0x11, SPI:4 (0x00))
x: 2.4120
y: -2.8786
z: -7.9107
temperature: 45.1250
error_count: 0
clip_counter: [0, 0, 0]
samples: 1

Instance 2:
timestamp: 465776512 (0.000456 seconds ago)
timestamp_sample: 465776239 (273 us before timestamp)
device_id: 2359306 (Type: 0x24, SPI:1 (0x00))
x: 0.0962
y: -0.0699
z: -9.7784
temperature: 55.3128
error_count: 0
clip_counter: [0, 0, 0]
samples: 5

Output from Raspberry Pi Agent:
ubuntu@ubuntu:~$ micrortps_agent -d /dev/ttyUSB0 -b 921600 -t UART
— MicroRTPS Agent —
[ micrortps_agent ] Starting link…
[ micrortps_agent ] UART transport: device: /dev/ttyUSB0; baudrate: 921600; poll: 1ms; flow_control: No
— Subscribers —

DebugArray subscriber started
DebugKeyValue subscriber started
DebugValue subscriber started
DebugVect subscriber started
OffboardControlMode subscriber started
OpticalFlow subscriber started
PositionSetpoint subscriber started
PositionSetpointTriplet subscriber started
TelemetryStatus subscriber started
Timesync subscriber started
VehicleCommand subscriber started
VehicleLocalPositionSetpoint subscriber started
VehicleTrajectoryWaypoint subscriber started
OnboardComputerStatus subscriber started
TrajectoryBezier subscriber started
VehicleTrajectoryBezier subscriber started
TrajectorySetpoint subscriber started
VehicleMocapOdometry subscriber started
VehicleVisualOdometry subscriber started

---- Publishers ----

Timesync publishers started
TrajectoryWaypoint publisher started
VehicleControlMode publisher started
VehicleOdometry publisher started
VehicleStatus publisher started
CollisionConstraints publisher started
TimesyncStatus publisher started
SensorCombined publisher started
VehicleTrajectoryWaypointDesired publisher started

[ micrortps_agent ] Interrupt signal (2) received.
[ micrortps_transport ] Closed UART.
[ micrortps_agent ] RECEIVED: 10318 messages - 1338737 bytes; 36369 LOOPS - 36.680 seconds - 36.50KB/s
[ micrortps_agent ] SENT: 369 messages - 19188 bytes

if you command in a new terminal like first ros2 run px4_ros_com sensor_combined_listener then in another terminal ros2 topic pub /fmu/sensor_combined/out you can see the outputs BUT if you see correct output could you look my issue: