i2c query tool (ls_i2c)

Copyright (c) 2026 BitBank Software, Inc.
Written by Larry Bank
email: bitbank@pobox.com

What does it do?

The ls_i2c tool is meant as a friendlier and more functional replacement for the ancient Linux i2cdetect. The tool can scan multiple I2C buses at once and has the ability to auto-detect a growing list of popular I2C devices. The output is a neat list of detected addresses with device info (model and type) if it's one of the 50+ recognized devices. It uses the device address as a starting point and then matches unique info such as the WHO_AM_I register to determine what devices are responding.

Why did you write it?

Lately I've been doing a lot of work on my sensor libraries and have run into some frustrating problems with getting the I2C overlays to work on my collection of Linux SBCs. I have had to run i2cdetect many times and every time I did, it made me think there must be a better way to display that info. Making use of some code I wrote for my Arduino BitBang_I2C library turned out to be the right way to approach the problem. The result is a tool I find much more useful.

How does it look?

See the images below to compare the output of i2cdetect (top) versus ls_i2c (bottom) for the same machine and sensors.

Getting started

The project is composed of a single .C file and makefile. Simply clone the repo and type 'make' to build it. When you run the tool without any parameters, instructions will be printed on the terminal.

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