ROS2 GAMEPAD ROVER

Tiny experiment to interface Bluetooth control and ROS2

I had originally planned on making this page a super detailed explanation of how I did this and all the issues I had to fix, but I ran out of time to finish the page and build log over winter break, so here's a cleaned-up version of the notes I made when working through this project. There are a lot of links to pages that solved my specific issues. Think of this as a combination of works cited and appendix for the youtube version.

I plan on cleaning this page up at some point, but needed to get this project online so I can focus on my coursework (I get to work on Robot Arms this semester!)

I installed everything on a 2gb Raspberry Pi 3B+, you can install full Ubuntu Desktop if you have a Pi 4 with 4gb, but I didn't at the time I did this project.

Ubiquity does have ros2 pre-installed distros, though they also will require some more powerful hardware. https://learn.ubiquityrobotics.com/noetic_pi_image_downloads

Code can be found at https://github.com/KeplerElectronics/ROS2_GAMEPAD_ROVER/tree/main, though its mostly just modifications of tutorial code to make everything mesh together.

General process:

Install Ubuntu server and get wifi working
Get Motor Hat Working
Get Pubsub example working from ROS documentation
Install and validate Joy package
Connect Subscriber node to Joy message
Set up Launchfile
Set up everything so it will run launchfile on startup

Here's the list of absolutely necessary docs:

Make sure to source Joy!!

https://get-help.robotigniteacademy.com/t/ros2-foxy-package-joy-not-found/14287

source /opt/ros/foxy/setup.bash Test controller input while joy is running with

ros2 topic echo joy

I used an 8bitdo SF30Pro wired. I was able to make bluetooth work, then it broke upon shutdown and I never bothered to fix it. For my uni Lunabotics project, I'm pushing for a 2.4G wireless controller with a dongle.

you can try and use this for pairing https://ubuntu.com/core/docs/bluez/reference/pairing/outbound-pairing

Create a Launchfile

https://docs.ros.org/en/foxy/Tutorials/Intermediate/Launch/Creating-Launch-Files.html

Error code -2 is the script not being able to handle ros giving it arguments. I cannot find how to accept arguments anywhjere for ros2

https://robotics.stackexchange.com/questions/22896/roslaunch-exit-code-2-error

(I saved this page but can't remember why, so here it is since I probably used it as a source) https://answers.ros.org/question/229185/roslaunch-namespace-substitution-within-group-tags/

The reason this wasn’t working was because I specified a separate namespace for joy. Removing that made it work like a charm

Add launch stuff to .bashrc

https://answers.ros.org/question/87866/how-to-edit-the-bashrc-file/ https://ostechnix.com/ubuntu-automatic-login/

BONUS NOTES :D

Follow ros instructions to build package, this is pretty useful https://docs.ros.org/en/humble/Tutorials/Beginner-Client-Libraries/Creating-Your-First-ROS2-Package.html

From the hello world package, add the adafruit motorkit stuff in, rebuild with colcon and run it, motor should move. (make sure that everything is plugged in)

Make sure to source the ROS scripts!!!

source install/local_setup.bash https://docs.ros.org/en/humble/Tutorials/Beginner-CLI-Tools/Understanding-ROS2-Nodes/Understanding-ROS2-Nodes.html

You can name different ros nodes in the setup file, allowing you to run them individually

Gave up and just tried to get the pubsub example working - it ran! Use ctrl alt f2 to get to new term to run other stuff

ROS2 GAMEPAD ROVER

General process:

Ubuntu Install

ROS2 Install

Motor Hat Install

Publisher/Subscriber

Install Joy

Create a Launchfile

Add launch stuff to .bashrc

BONUS NOTES :D