RTPS Connection Problem

ROS / MAVROS / MicroDDS
1

Good morning everyone

I am actually trying to create a RTPS communication between my Pixracer and Rpi 3b+.
These two are connected by a Serial-USB converter (Telem1 at Pixracer, USB at Raspberry), appositely added for RTPS only.
The Client starts well, with the following command:

micrortps_client start -d /dev/ttyS1

Still, when trying to launch the Agent, with the following command:

micrortps_agent -d /dev/ttyUSB0

The terminal launches the Publishers/Subscribers, but then right after says:

    terminate called after throwing an instance of 'std::system_error'
      what():  Resource temporarily unavailable
    Aborted

giving you the exact output here, for more info you may search for:

--- MicroRTPS Agent ---
- Starting link...
- UART transport: device: /dev/ttyUSB0; baudrate: 460800; sleep: 1us; poll: 0ms
No flush
--- Subscribers ---
- CameraCapture subscriber started
- CameraTrigger subscriber started
- CollisionReport subscriber started
- DebugArray subscriber started
- DebugKeyValue subscriber started
- DebugValue subscriber started
- DebugVect subscriber started
- ObstacleDistance subscriber started
- OpticalFlow subscriber started
- PositionSetpoint subscriber started
- PositionSetpointTriplet subscriber started
- Timesync subscriber started
- TrajectoryWaypoint subscriber started
- VehicleAttitudeSetpoint subscriber started
- VehicleLocalPositionSetpoint subscriber started
- VehicleTrajectoryWaypoint subscriber started
- OnboardComputerStatus subscriber started
- VehicleMocapOdometry subscriber started
- VehicleVisualOdometry subscriber started
- TrajectorySetpoint subscriber started
--------------------

---- Publishers ----
- ActuatorArmed publisher started
- AdcReport publisher started
- Airspeed publisher started
- BatteryStatus publisher started
- Cpuload publisher started
- DistanceSensor publisher started
- EstimatorStatus publisher started
- HomePosition publisher started
- IridiumsbdStatus publisher started
- RadioStatus publisher started
- SatelliteInfo publisher started
- SensorBaro publisher started
- SensorCombined publisher started
terminate called after throwing an instance of 'std::system_error'
  what():  Resource temporarily unavailable
Aborted

I still cannot find a solution.
Any suggestions?
Thank you, wish you a nice day.

2

Please check Unexpected topic ID when starting micrortps agent for more context on how you can solve the above.

4

Thank you!
I managed to solve this problem weeks ago, I was launching too many topics and my Rpi couldn’t handle them when the agent got started; I solved by reducing the number of topics to the one I needed most.

Now the stream seems to work, still need to verify the topics’ content.
Still, when I start the agent, I get a series of “BAD CRC number!=number” messages, and the connection sometimes closes after some messages got exchanged successfully; In case it doesn’t close, the BAD CRC messages disappear after a while and the channel stays alive…any suggestions about this “issue”? I still don’t get what that BAD CRC message means.
Thanks in advance

5

Managed to solve this with a newer version of px4_ros_com.
Meanwhile, I got a new problem but I will create another topic about it. Thanks!