The last couple of years has seen a plethora of hackable smartwatches designed to be programmed through open frameworks, such as Arduino. 
For what is quite a bit of technology, there aren’t many parts to Watchy ($59). It comes as a PCB, an e-ink screen (which plugs in via a ribbon cable), a watch-case, and a battery. Assembly is surprisingly easy: pop the ribbon cable on, plug in the battery, snap on the case, and insert the watch-strap.

If you opted for the aluminium case, there are an additional four screws that hold everything in place. There’s also a bit of adhesive that you can use to hold the screen in place, and a screen protector that can also be added. It took us longer to find an appropriately sized Allen key in our disorganised workshop than it did to assemble the watch, (we later realised that there was an Allen key included which we hadn’t spotted).

Add some power (via the micro USB cable) and you’ve got a watch.

We tested it with the aluminium case, which is quite industrial-looking. If this isn’t to your tastes, there’s a selection of 3D-printable options on the Watchy website.

This isn’t a small watch, but it’s certainly one of the smallest hackable watches we’ve come across. We found it unobtrusive and comfortable to wear. While the aluminium case is tough, it isn’t waterproof and doesn’t offer any protection to the screen other than the stick-on screen guard.


Watchy is unashamedly a watch for programmers, and some parts of configuration can only be done via code. For example, the default seven-segment watch-face includes the current weather forecast. However, this is hard-coded to New York unless you make a change to the configuration file, recompile, and upload. We’ll look more closely at how to build your own watch-face in a future issue.

The other stand-out feature of Watchy is the e-ink screen. This is easily readable in daylight and always on (unlike watches with TFT-based screens that typically turn off to save power). There are 200×200 pixels, so plenty of space to display information, but they can only be black or white (not greyscale or colour), so there’s no anti-aliasing, and text looks a little more blocky than it would on an equivalent-sized TFT. The other downside of this display is that it’s not readable in a dark room. That’s simply the payoff for low-power displays. It’s personal preference, but it does feel nicer to have a display that turns on and.

It’s this low power that is probably our favourite  feature of Watchy. Exactly how long Watchy will run depends significantly on the WiFi. Running it as just a timekeeper, ours lasted around a week. With it also fetching data over WiFi every hour, this dropped to a few days.

There are loosely two schools of thought about smartwatches. Some people fundamentally want a watch that perhaps has an extra feature or two. Other people fundamentally want a wearable computer that they can bend to any purpose. Watchy will appeal to the former more than the latter. The always-on e-ink screen is a good canvas for expressing yourself in time-based artwork, and there’s already a range of watch-faces you can play with. There are enough smarts to augment this a little bit with, for example, the weather and step counting. However, if you want to do more complex online or interactive things with the watch, you’ll start to run into the limitations of the form factor and display technology.

There are a couple of things that we’d like to see on the watch: there’s no charge indicator, there’s a missing connection that makes it hard to maintain low-power Bluetooth connections, and we’d be very interested in an e-ink screen with more colours (some are available in similar form factors). However, these are minor issues. Watchy is a great platform for building your own expressive timepiece.



Arduino-compatible e-ink-powered wrist blinken.

From HackSpace magazine store


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