The Smart Buckle from Gooseberry uses a Bluetooth chip with power management from Nordic Semiconductor powered by a custom 19mAh lithium polymer battery. The buckle is charged via a two pin, magnetically attached micro-USB connector. A 60 minute charge supports a week of operation with the buckle linked to a smartphone via Bluetooth 4.2 Low Energy.
Smart Buckle has been developed by Shripal Gandhi and Alexei Levene to fit a standard 20mm leather, rubber and cloth watch band. It tracks steps and sleep patterns and links to both the Apple Health and Google Fit apps. Levene is also a director of London-based solar powered desalination technology developer Desolenator.
The Smart Buckle is currently on Kickstarter.