At first, smartwatches were like little tiny tablets or phones that you wore on your wrist. More recently though we have noticed more “hybrid” smartwatches, that look like a regular watch, but that use their hands to communicate data. For example you might hear a text message come in and then see the hand swing to 1, indicating it is your significant other. Want to roll your own? The OpenChronograph project should be your first stop.
The watches are drop in replacements for several Fossil and Skagen watch boards (keep in mind Fossil and Skagen are really the same company). There’s an Arduino-compatible Atmega328p, an ultra low power real time clock, a magnetometer, pressure sensor, temperature sensor, and support for a total of three hands. You can even create PCB artwork that will act as the watch face using Python.
You can see a video of how you’d replace an existing watch’s PCB with the new version. You’ll also need a special tiny POGO pin programmer since there isn’t much room in the little case.
Honestly, opening the watch looked a little frightening to us, but at least the hybrid watches aren’t usually that expensive. You can usually find a Hagen or a Men’s Machine for under $100. A Fossil Q Activist looks as though it might come in at just a little bit more.
Of course, you could skip the existing watch and build one all the way. Some are easier to build than others.