colmi_r02_client is an open source Python client to read data from the Colmi R02 family of Smart Rings. It is 100% open source, 100% offline.
What is the Colmi R02 family?
It’s a cheap (as in $20) “smart ring” / fitness wearable sold on AliExpress.
It includes the following sensors:
- Accelerometer
- step tracking
- sleep tracking
- gestures (maybe…?)
- Heart Rate (HR)
- Blood Oxygen (SPO2)
Wesley Ellis has been reverse engineering the Colmi to get data without their app.
Check out the page on GitHub.io and the docs page. This page is a “stream of conscience” of the project and the GitHub site.




