The smart accessory port on the back of Pebble Time, Pebble Time Steel, and Pebble Time Round makes it possible to create accessories with electronics built-in to improve the capabilities of the watch itself. Wrist-mounted pieces of hardware that interface with a Pebble watch are called smartstraps and can potentially host many electronic components from LEDs, to temperature sensors, or even external batteries to boost battery life.
This section of the developer guides details everything a developer should need to produce a smartstrap for Pebble; from 3D CAD diagrams, to electrical characteristics, to software API and protocol specification details.
Hardware Specification - Details of how to build smartstrap hardware, including 3D printing instructions and electrical characteristics.
Protocol Specification - Reference information on the Pebble smartstrap protocol.
Talking To Pebble - Information on how to implement the smartstrap protocol to talk to the Pebble accessory port.
Talking To Smartstraps - Information on how to use the Pebble C API to talk to a connected smartstrap.
The Smartstrap API is available on the following platforms and firmwares.
| Platform | Model | Firmware |
|---|---|---|
| Basalt | Pebble Time/Pebble Time Steel | 3.4+ |
| Chalk | Pebble Time Round | 3.6+ |
Apps that use smartstraps but run on incompatible platforms can use compile-time defines to provide alternative behavior in this case. Read Building for Every Pebble for more information on supporting multiple platforms with differing capabilities.
Watch the video below for a detailed introduction to the Smartstrap API by Brian Gomberg (Firmware team), given at the PebbleSF Meetup.