Need help for XRCE_DDS with pixhawk 6C

wntun · February 16, 2024, 9:18am

I want to apply ROS2 with the ardupilot copter. Following AP_DDS readme file, I built the firmware with enable-dds option. As you check in the picture, it showed that the if02 directory was not found. But, there is no other error.

After that, I updated the parameters for the protocol and baud rate.

Then, I run the MicroXRCE. But, it’s not working.

I can do SITL gazebo simulation using UDP option. I wonder what’s the problem with the hardware. I found the similar situation (Is it possible to test XRCE DDS on real HW? - #6 by lalal2017).
I tested with miniterm. It didn’t show anything on jetson. But, with raspberry pi, it showed some hexa texts, but the MicroXRCE didn’t work.
I just started using the Ardupilot and couldn’t found the resources online.
Someone help me, please.

rhys · February 16, 2024, 11:04am

Hello @wntun, It looks like you are trying to connect the micro-ROS agent to SERIAL0 on /dev/seria/by-id/*-if00 which you are using for mavlink and console. You have configured SERIAL7 for DDS which is on /dev/seria/by-id/*-if02, so the micro-ROS agent command should be:

MicroRosXRCEAgent serial -b 115200 -D /dev/serial/by-id/usb-Holybro_Pixhawk6C_3E0042000951303433038-if02 -r dds_xrce_profile.xml -v6

Run initially with the -v6 flag to verify the connection is established.

The documentation is here: ROS 2 — Dev documentation

wntun · February 19, 2024, 12:28am

Hello, @rhys. I tried with -v6 using the *-if02. It didn’t work either.

The one that I found is that when I tried using miniterm test, I got some strings from *-if00.

Do you have any other ideas, please?

wntun · February 19, 2024, 1:19am

Hello, I can see the topics using the UART (but didn’t get them using USB). It’s weird.
Thanks a lot! @rhys