What is it?

This tool is designed to simplify the development and testing of systems using custom I2C protocols. Essentially, it functions like a USB to Serial Converter, but tailored specifically for the I2C interface, providing a seamless bridge between USB and I2C devices.
Two I2C interfaces can be controlled via USB using the corresponding GUI or Python package. I2C master requests or I2C slave configurations can be created and send to the I2C interfaces. The GUI displays performed master requests, slave configurations and slave access notifications.

Python package

After running pip install interface-expander on your system the device can by easily controlled via python code, as shown by the example below:

More examples can be found here.

Why did I make it?

After finding myself in need of emulating an I2C subsystem and not being able to find an I2C to USB Converter with an intuitive UI for development and testing, I decided to create one myself. With this device and its GUI software, it is fast and easy to emulate and test a custom protocol on either the I2C master or slave side. This is especially helpful when one of the subsystems is not yet available.

The GUI software can be downloaded from GitHub

Note: In the upcoming months the following features will be added:

• The GUI software will be made available for linux
• Support for USB to SPI conversion through a firmware update