Maxwell Pray's Arduino Timex Datalink Adapter Brings Back a Classic Wearable of the 1990s

Embedded developer and retro wearable enthusiast Maxwell Pray has put together a project designed to turn an Arduino-compatible board into a replacement for the Timex Datalink Notebook Adapter — without requiring a single extra component beyond the board itself.

"This project emulates the Timex Datalink Notebook Adapter for early Timex Datalink watches in Arduino," Pray explains. "It is 100 per cent compatible with the original Notebook Adapter, and works with vintage and modern computer hardware."

The Timex Datalink — originally launched as Data Link — family was an early implementation of what we would today call a smartwatch. Developed by Timex in partnership with Microsoft, the Datalink watches launched in 1994 as an alternative to then-popular personal digital assistants (PDAs) designed to put schedule and other handy data on your wrist.

Getting the data from a desktop wasn't quite as straightforward as it may seem: lacking wireless or USB connectivity at launch, the devices relied on detecting a pattern of flashing images on a CRT monitor using a light sensor — while laptop users relied on the Timex Datalink Notebook Adapter, which replaced the CRT with a flashing LED.

Now that the whole world — with a few exceptions — has moved away from CRT displays in favor of LCDs, the Notebook Adapter is more important than ever. It's also long-discontinued, which is where Pray's replacement comes in: a pure-software hack that flashes any Arduino-compatible board's on-board LED in order to program early light-based Datalink watches, no CRT monitor required.

"This project is not dependent on any specific Arduino board, although it is designed with the Teensy LC in mind," Pray explains. "The Teensy LC has USB serial and an onboard LED, so the board can be used as-is without any external components."

The project is available on Pray's GitHub repository under an unspecified open source license.