Installation

System Prerequisites

smbus2 requires:

Linux — the library uses Linux-specific ioctl calls and /dev/i2c-* devices.
I2C kernel support — the i2c-dev kernel module must be loaded. On most distributions this is either built in or can be loaded with:
```
sudo modprobe i2c-dev
```
To load it automatically at boot, add i2c-dev to /etc/modules.
Device permissions — the user running your Python script must have read/write access to /dev/i2c-*. The easiest way is to add the user to the i2c group:
```
sudo usermod -aG i2c $USER
# Log out and back in for the change to take effect
```
Alternatively, run with sudo (not recommended for production).

pip install smbus2

Installs the latest stable release. Use a virtual environment to avoid polluting the system Python environment.

Note

uv users can use uv add smbus2 (uv-managed projects) or uv pip install smbus2 (ad-hoc virtual environments).

conda install -c conda-forge smbus2

git clone https://github.com/kplindegaard/smbus2.git
cd smbus2
python setup.py install

Or, using pip in editable mode (preferred for development):

pip install -e .

python -c "import smbus2; print(smbus2.__version__)"

You can also verify that your I2C bus is accessible:

from smbus2 import SMBus

with SMBus(1) as bus:
    print("Bus opened successfully")