No Time for Distractions

If we are honest about it, those of us working in technology (myself included!) are some of the most fickle of all people. Consider popular software architectures, for instance. We started with monolithic applications, then microservices became all the rage, then back we went toward monolithic applications, and so it will continue until the end of time. The grass is always greener on the other side — until we step over and experience a whole new set of problems that has us longing for the good old days when — thanks to our fading memories — things seemed simpler.

Perhaps smartwatches are about to fall into a similar cycle. We started with relatively simple watches like dedicated fitness trackers and the Pebble (which is undergoing a revival, if you have not heard). These watches did relatively few things, but (for the most part) they did those things quite well. Now we have smartwatches that attempt to do everything imaginable, but they do a very poor job at a large percentage of those things. The box may be checked off on the marketing materials, but the user experience is terrible.

Andrew Childs has been looking for the perfect smartwatch to help his nine-year-old son with type 1 diabetes monitor his glucose levels, and generally better manage his condition without having to constantly think about it. The Apple Watch was the obvious first place to look, since it can handle a job like this (and just about everything else too). But even cursory research shows that diabetics are generally very unhappy with the Apple Watch as a monitoring device. Many find it to be unreliable and full of irrelevant distractions.

With nothing available to meet his needs, Childs decided to build a custom smartwatch from scratch, specifically for use by a child in managing diabetes. No distractions, no fragile design — just a barebones monitor that does one thing and does it very well.

The primary job of this custom watch is to wirelessly communicate (via Bluetooth) with an on-body continuous glucose monitor to capture frequent measurements. When the reported glucose levels are concerning, the watch must provide some type of notification to alert the wearer so that they can take an appropriate action immediately.

To make this device a reality, Childs first spent some time prototyping with off-the-shelf components like the M5Stick, Arduino development boards, and other breadboard-friendly modules. This work proved that the basic functions could be developed, but naturally this type of hardware was too bulky to fit inside a watch case. So Childs got busy designing a custom PCB with only the essential components to shrink things down to size.

This too was a long drawn-out process that involved lots of iteration and frustration. Anyone that has ever worked on something like this knows that problems lurk around every corner — and not just when it comes to the electronics. Even installing the glass over the display was a big issue. It requires a big and expensive piece of equipment to get all the air bubbles out, but Childs improvised and was able to get the job done with a cast-iron tortilla press, of all things. Hey, whatever works!

After a couple years of work, Childs had finally built the perfect watch for his son. It looks almost as good as a commercial device, and it only costs about $50 in parts in single-unit quantities. That cost does not factor in the time spent, of course, but since Childs has already done all of the hard work, anyone else that needs a similar watch can save a lot of time by copying the design.