Px4_msgs module not found

ROS / MAVROS / MicroDDS
1

I am trying to get the RTPS bridge working: ROS 2 User Guide (PX4-ROS 2 Bridge) | PX4 User Guide and have run into 2 situations:

1: On a Jetson Nano running Ubuntu 20.04, I can follow the sanity check until the fourth step, which runs but doesn’t print the sensor data:

jetson@nano:~$: source ~/px4_ros_com_ros2/install/setup.bash
jetson@nano:~$: ros3 launch px4_ros_com sensor_combined_listener.launch.py
[INFO] [launch]: All log files can be found below /home/jetson/.ros/log/2022-
07-11-09-27-40-509653-nano-16128
[INFO] [launch]: Default logging verbosity is set to INFO
/home/jetson/px4_ros_com_ros2/install/px4_ros_com/share/px4_ros_com/launch/se
nsor_combined_listener.launch.py:50: UserWarning: The parameter 'node_executable' 
 is deprecated, use 'executable' instead
  launch_ros.actions.Node(
[INFO] [sensor_combined_listener-1]: process started with pid [16146]
[sensosr_combined_listener-1] Starting sensor_combined listener node...

However if I run

ros2 topic list

I can see the /fmu/sensor_combined/out topic
But running

ros2 topic echo /fmu/sensor_combined/out

or

ros2 topic hz /fmu/sensor_combined/out

results in

ModuleNotFoundError: No module named 'px4_msgs'

2: On my laptop, also running Ubuntu 20.04, the python script

ros2 launch px4_ros_com sensor_combined_listener.launch.py

is able to show the sensor data, but if I try to echo or see the refresh rate of the topic, I also get a ModuleNotFoundError: No module named ‘px4_msgs’

In my px4_ros_com_ros2 directory on both the Jetson and laptop, I have cloned px4_ros_com and px4_msgs

Thanks for your help!

2

I was able to get it working on my laptop. To see refresh rate or echo, it seems the setup script needs to be sourced as well. However the jetson still does not have any data. I am able to publish using

ros2 topic pub /fmu/sensor_combined/out

to the topic, and the data is visible from the python script, but if I just start the simulation and run the script, no data is shown