Overview

This ROS 2 package sits as the cherry on top of two other ROS 2 packages:

1. The ez-turtlebot3 fork of OpenCR, which extends the TurtleBot3 OpenCR firmware to read data from its analog pins, A0-A5.
2. The ez-turtlebot3 fork of turtlebot3, which extends the turtlebot3_node to publish that analog pin data to the ROS 2 topic /analog_pins.

ez_analog_processor then takes /analog_pins data as input, processes that data, and publishes that processed data to several new topics.

ROS Setup

ROS package prerequisites

• ROS 2 Humble
• Python 3.10 or later

This is a standalone ROS 2 package, so it can be installed on the TurtleBot's Raspberry Pi or the remote PC. That said, the /analog_pins topic is published when the TurtleBot3 is running:

• ez-turtlebot3's modified OpenCR firmware
  • Find these installation instructions in the repo's README.
• ez-turtlebot3's modified TurtleBot3 packages
  • Find these installation instructions in the repo's README.

Building from Source

1. Clone this repository into your ROS 2 workspace:

cd ~/turtlebot3_ws/src
git clone https://github.com/ez-turtlebot3/ez_analog_processor.git

2. Build the package:

cd ~/turtlebot3_ws
colcon build --packages-select ez_analog_processor

3. Source the workspace:

source ~/turtlebot3_ws/install/setup.bash

ROS Configuration

Set up config/sensors.yaml for your hardware. This file is gitignored to prevent accidental commits of user-specific settings. The example files provide templates with default values that you can modify for your setup.

ROS use

1. To start the node: ros2 launch ez_analog_processor analog_processor.launch.py
2. That's it! Maybe set up a live plot with PlotJuggler.

AWS IoT Setup

AWS Prerequisites

• Someone on your team will have to set up your device on AWS IoT, on AWS.
• That someone will need to give you your
  • AWS IoT endpoint
  • AWS IoT certificates
  • AWS IoT device private key
  • Names for the MQTT topic and sensor type
• Include these things, or filepaths to them, in your bashrc file. Example export statements can be found in bashrc_exports.example

Create the environment for the AWS publisher

Publishing to AWS IoT requires the awsiotsdk Python package, which I could only install to my Raspberry Pi when I installed it in a virtual environment. The AWS IoT functionality and its virtual environment are kept separate from the rest of the ROS package. Follow these steps to set them up:

1. Complete the ROS Setup.
2. Create the virtual environment and install Python requirements inside.

cd ~/turtlebot3_ws
python -m venv .venv
source .venv/bin/activate
pip3 install -r src/ez_analog_processor/requirements.txt

3. You might have to source the workspace again, I'm not sure about this one. source ~/turtlebot3_ws/install/setup.bash

AWS use

1. Source the virtual environment if you don't have it active already source ~/turtlebot3_ws/.venv/bin/activate
2. Run the script python3 ~/turtlebot3_ws/src/ez_analog_processor/aws_publisher/publish_analog_pins_data_to_AWS.py

Dependencies

This package has dependencies managed through multiple systems:

• ROS 2 dependencies

  • Managed through package.xml
  • Installed automatically by the ROS 2 build system

• Python dependencies

  • Managed through requirements.txt
  • Must be installed manually with: pip3 install -r requirements.txt

• Development dependencies for testing and code quality

  • pytest - Python testing framework
  • pre-commit - Git hooks for code quality
  • Install with: pip3 install pytest pre-commit

See package.xml and requirements.txt for complete dependency specifications.

Setting up Pre-commit Hooks

This repository uses pre-commit hooks to ensure code quality and prevent accidental commits of sensitive information. To set up the pre-commit hooks:

1. Install pre-commit:

pip3 install pre-commit

2. Install the git hooks:

pre-commit install

The hooks will now run automatically on each commit. They will:

• Check for accidental commits of secrets using gitleaks
• Format and lint Python code using ruff
• Check for common issues like trailing whitespace and merge conflicts

To manually run the hooks on all files:

pre-commit run --all-files

License

This project is licensed under the MIT License - see the LICENSE file for details.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.