ssh problem: computers can't see each other's ros topics

[khuechuong]

ROS Noetic, rover pro 4WD

For some reason, git clone libover and roverrobotic_ros1 won't connect nuc to the rover. When I roslaunch roverrobotic_driver pro.launch it acts like I didn't plug USB in. I tried running it with and without USB plugged in and the same result happened. So I just used rover_tools_ros1 (on the onboard computer) and it worked. NOW, HERES THE REAL PROBLEM:

Okay so this is what I did:

• For the onboard computer (intel nuc), I edit bashrc file to
  • export ROS_MASTER_URI=http://localhost:11311
  • export ROS_HOSTNAME=IP_OF_INTEL
• For the laptop, I edit bashrc file to
  • export ROS_MASTER_URI=http://IP_OF_INTEL:11311
  • export ROS_HOSTNAME=IP_OF_LAPTOP

Then on the laptop:

• terminal 1: I did ssh -Y IP_OF_INTEL and I was able to run teleop to move it around and access to all topics
• terminal 2: which is the laptop terminal, since I didn't ssh, and when I ran rostopic list, it said "ERROR: Unable to communicate with master!".

I tried the same thing before using the rover_tools_ros1 ./start command:

• terminal 1: I did ssh -Y IP_OF_INTEL and I ran roscore
• terminal 2: which is the laptop terminal, since I didn't ssh, and when I ran rostopic list, it display the 2 topic that roscore have.

This made me conclude that maybe rover_tools_ros1 installation made it unable to receive any information with ssh. My other solution is using manually git clone libover and roverrobotic_ros1, but it won't work as I state in the beginning.

How should this be fixed? Am I doing something wrong? Let me know if you need any more info thx!

[khuechuong]

It seems that the shellscript already did

• export ROS_MASTER_URI=http://localhost:11311/
• export ROS_HOSTNAME=localhost

which to my knowledge is for a single machine. Is there a way to fix it?

[khuechuong]

I figured out the solution lol. After reading the shellscript, I figure I just go straight into /etc/roverrobotics/env.sh and edit the export ROS_HOSTNAME=IP_OF_INTEL then rebooted.