The Pebble Time Smartstrap turned the back of a smartwatch into a small hardware-development platform. At Pebble Rocks Boulder in September 2015, makers used its four-pin connector to link the watch with littleBits, sensors, an Arduino Uno, NFC hardware, robots and other prototypes. The projects show how Pebble’s watch software and external electronics could be combined, but they were hackathon demonstrations—not evidence of a supported product or service today.
How the Pebble Smartstrap connector worked
Viget’s account describes the Smartstrap as a four-pin connector on the rear of the Pebble Time. Developers could attach peripheral electronics through that physical interface and use a Pebble app or watchface as the software-facing part of the project. Pebble had published mechanical details, assembly instructions, protocol documentation and an example Arduino library at the time, giving builders enough information to design straps and connected circuits. The historical event report is available from Viget; Make’s project coverage is at Make:.
That arrangement invited experimentation because the watch could provide the display, controls and application logic while a strap supplied the specialized hardware. A strap therefore did not have to be a conventional band: it could be a sensor carrier, a communications concept, a payment device or an interface to another machine.
What makers built at Pebble Rocks Boulder
| Project | Purpose | Additional hardware | Interaction and status reported in 2015 |
|---|---|---|---|
| Pebblits | Make watch-connected prototyping approachable | littleBits modules | A button press on a littleBits module produced something on the Pebble Time screen; Juan Sanchez said, “We met that goal the first day.” |
| Altimeter Smartstrap | Provide elevation information for hikers, hang gliders and other users | Altitude-sensing strap hardware and a watchface | Displayed elevation, whether the wearer was ascending or descending, and a graph of the last ten measurements. |
| SurvivalStrap | Explore a survival and search-and-rescue communication concept | Pebble Time, Arduino Uno and simple electronic components | The proposed Pebble app would trigger transmission of GPS information over public spectrums monitored by search-and-rescue teams and include basic survival guides. It was a prototype concept, not a validated emergency system. |
| NFC payments | Attempt contactless payment from the watch | Secure element and NFC controller embedded in a Smartstrap | FitPay reported completing a retail transaction during the event. That account does not establish a current payment service. |
| Other builds | Control or augment physical devices | 3D printer, robotic arm and a 3D-printed audible-notification dock | The watch controlled a 3D printer and a robotic arm in separate projects; another build housed an audible notification dock. |
How do I make a Pebble Smartstrap?
The event reports point to a general workflow rather than a single recipe. A builder would design the strap mechanically, connect the external circuit to the four-pin interface, write the Pebble-side app or watchface, and test the interaction between the two. Pebble’s 2015 documentation reportedly covered the connector’s mechanical details, assembly guidance and protocol, while the example Arduino library illustrated a way to connect a development board.
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- Choose one job for the strap. Decide whether the watch will display sensor data, issue a control command, provide a user input, or host a transaction interface.
- Plan the external electronics. Match the chosen function to the hardware used by the project—for example, littleBits for approachable prototyping or an Arduino Uno and simple components for the SurvivalStrap prototype.
- Build the physical interface. Use the published mechanical information from the period to make the connector, enclosure and strap assembly. The original documents’ present availability and compatibility have not been established.
- Implement the watch software. Create the app or watchface that presents readings, responds to a button or sends a command to the strap.
- Test the complete interaction. Verify electrical behavior, mechanical fit and the watch’s response before treating the result as anything more than a prototype.
Parts mentioned in the event accounts include Smartstrap hardware, an Arduino Uno development board, GPS-related electronics, simple electronic components, littleBits, paracord and 3D-printing materials. They are project-specific categories, not a universal bill of materials, and current stock or revision compatibility is not established here.
Why the projects mattered
A low barrier to physical computing
Pebblits connected littleBits to the watch so that a simple physical button could produce an immediate on-screen result. That approach lowered the entry cost for people who wanted to explore hardware without first designing a custom circuit board.
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A watch as an instrument display
The Altimeter Smartstrap treated the Pebble Time as a glanceable instrument. Its reported elevation trend and ten-reading graph show a useful division of labor: the strap sensed conditions while the watchface interpreted them for the wearer.
A watch as a control surface
The 3D-printer and robotic-arm projects used the watch to control larger machines. In these examples, the Smartstrap interface extended the watch beyond notifications into physical action.
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A platform for ambitious concepts
SurvivalStrap and the NFC project demonstrate how quickly a small connector could lead to high-stakes ideas. The former proposed search-and-rescue communication; the latter combined a secure element and NFC controller and reported one retail transaction. Neither report supplies the testing, certification or ongoing service needed to treat those concepts as dependable products.
What the hackathon demonstrated—and what it did not
Make reported that 23 teams each created a project, while Viget reported more than 70 participants and 23 projects uploaded to the event’s Hackster.io page. Make also described a $1 million fund that Pebble had announced to encourage development and commercialization of Smartstrap projects. Those figures describe the 2015 event and its plans; they are not current participation numbers, funding opportunities or evidence that the old platform remains supported.
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- The projects were prototypes or demonstrations from September 2015.
- No standardized performance measurements or head-to-head testing were reported.
- The SurvivalStrap account does not prove reliable emergency communication.
- The NFC account does not prove that a payment service is available now.
- Current Pebble Time or Smartstrap inventory, support status and access to the period’s technical documents are not established by these reports.
Sources and historical context
Alasdair Allan’s Make: report, “Hacking on the Pebble Smartstrap,” was published September 25, 2015: https://makezine.com/article/maker-news/hacking-on-the-pebble-smartstrap/. Viget’s event account, “Pebble Rocks Boulder – Hardware Innovation Packed into a Weekend Hackathon,” was published September 11, 2015: https://www.viget.com/articles/pebble-rocks-boulder-hardware-innovation-packed-into-a-weekend-hackathon/.
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