tutorials ℹ️

This package is for learning ROS 2 and can be combined with the Nuclino documentation. 📓

Example Code

Inside of the tutorial folder, there are python examples on how to code certain features. More code will be added in the future, and all code is done in Python. Currently, there are four example scripts:

• Publisher: Publishes "Hello World" over the network. It can be run by the following command:

  ros2 run tutorials publisher

  Full information on this script can be found on Nuclino.

• Subscriber: Subscribes to the "Hello World" message over the network and prints the status to the screen. It can be run by the following command:

  ros2 run tutorials subscriber

  Full information on this script can be found on Nuclino.

• Client: Runs a service client that requests two integers to be added together and returns the sum from the service node. It can be run by the following command:

  ros2 run tutorials client

  Full information on this script can be found on Nuclino.

• Service: Runs a service that sums the two integers from the client together. It can be run by the following command:

  ros2 run tutorials service

  Full information on this script can be found on Nuclino.

When developing your own ROS 2 code, please use this code as an example to learn. More code can be found on Nuclino and they can be used as a basis for developing the whole software stack. If still stuck, please ask questions to your STR.

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Script Conversion Task

One of the first programs everyone on the software team has to do, prior to converting their first real script, is to convert the heartbeat_sub.py script. The original script can be found on GitHub in the rover repository here.

Here is the process you will need to follow:

1. Install this repository into the source folder of your current ROS 2 workspace. This can be a new one or an old one. 📦

2. Create a new branch called [name]. For example, you could call it harrison if you were me (I wonder who wrote this...).

3. Read through the previous script, understand what it does and the functionality it must provide. 📜

4. Create a new script in the new repository (in this case, this one) and set it to the correct name as per the naming conventions.

5. Replicate the script by programming the functionality using ROS 2, Python 3 and classes. Make sure all PEP8 coding conventions are followed. They can be found on Nuclino. 🐍

6. Make sure it works as expected using the command line ROS interface. You do not need to turn this into a launch file; simply running the following line is sufficient:

   python3 [file].py

7. Once happy with it working, add all your changes to GitHub on your current branch and make a pull request to the master branch. Make sure to add both Liam Whittle and Harrison Verrios to the pull request. Do not click merge.

8. The software STRs will then look through your code and provide feedback. 🚀

If you have any questions at all, please do not hesistate to contact us and ask away! That is what the #software Slack channel is for. :)