OBDII

A modern, easy to use, Python ≥3.8 library for interacting with OBDII devices.

Installing

Python 3.8 or higher is required.

A Virtual Environment is recommended to install the library.

# Linux/macOS
python3 -m venv .venv
source .venv/bin/activate

# Windows
py -3 -m venv .venv
.venv\Scripts\activate

Install from PyPI

pip install py-obdii

Install the development version

# From Github
pip install git+https://github.com/PaulMarisOUMary/OBDII@main[dev,test]

# From local source
git clone https://github.com/PaulMarisOUMary/OBDII
cd OBDII
pip install .[dev,test]

# From test.pypi.org
pip install -i https://test.pypi.org/simple/ py-obdii

Usage Example

Important

This library is still in the design phase and may change in the future.

from obdii import at_commands, commands, Connection

conn = Connection("COM5")

version = conn.query(at_commands.VERSION_ID)
print(f"Version: {version.value}")

response = conn.query(commands.VEHICLE_SPEED)
print(f"Vehicle Speed: {response.value} {response.units}")

conn.close()

Using the Library Without a Physical Device

To streamline the development process, you can use the ELM327-Emulator library. This allows you to simulate an OBDII connection without needing a physical device.

Setting Up the ELM327-Emulator

1. Install the library with "dev" extra options:

   pip install py-obdii[dev]

2. Start the ELM327-Emulator:

   python -m elm -p "REPLACE_WITH_PORT" -s car --baudrate 38400

Note

Replace REPLACE_WITH_PORT with the serial port of your choice

Use Virtual Ports on Windows

For Windows users, you can use com0com to create virtual serial ports and connect the ELM327-Emulator to your Python code.

1. Install com0com and create two virtual serial ports, (e.g. COM5 and COM6).

2. In the ELM327-Emulator, set the port to COM6.

3. In your Python code, set the connection port to COM5.

Contributing & Development

The development of this library follows the ELM327 PDF provided by Elm Electronics, with the goal of implementing most features and commands as outlined, starting from page 6 of the document.

This library aims to deliver robust error handling, comprehensive logging, complete type hinting support, and follow best practices to create a reliable tool.

Please, feel free to contribute and share your feedback !

Testing the Library with Pytest

This library uses pytest for testing. To run the tests, you need to install the library with the [test] extra option.

1. Install the library with "test" extra options:

   pip install py-obdii[test]

2. Run tests:

   pytest

Support & Contact

For questions or support, open an issue or start a discussion on GitHub. Your feedback and questions are greatly appreciated and will help improve this project !

• Open an Issue
• Join the Discussion

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