What Did I Learn
The TRMNL is an 800×600, 1-bit e-ink display related to a battery and a microcontroller, all housed in a pleasant but unremarkable plastic case. Because the microcontroller spends the overwhelming majority of the time sleeping, BloodVitals monitor and since e-ink displays do not require energy until they're updating, the battery can final six or extra months. It expenses over USB-C. When the microcontroller wakes up, it connects to a Wi-Fi network and communicates with a pre-configured server to fetch an 800×600 picture to show, and the duration of the next sleep. You can flash your own firmware on the gadget, BloodVitals monitor or level the usual firmware at a custom server. The corporate supplies an example server, though you can implement the (HTTP-based mostly) protocol in no matter way you would like. I considered working my own server, but thought I would give the easy path a strive first to see if it might suffice. The default service enables you to break up the display into several tiles, and there are a variety of pre-built and group-constructed things that may display in each.
None of them worked properly for me, but that is okay because you can create your personal private ones. They get knowledge either by polling a given URL, or by having knowledge posted to a webhook. The structure is rendered utilizing the Liquid templating system, which I had not used before, but it is fairly simple. I wrote a Go program hosted on Cloud Run which fetches the household shared calendar and converts occasions from the next week right into a JSON format designed to make it trivial to render within the templating system. With a 3D-printed holder, super glue, and some magnets, it is now happily caught to the fridge the place it shows the present date and the family occasions for the following week. Essentially the most awkward a part of the default service is managing the refreshes. The machine has a sleep schedule, and so do the tiles, which are solely up to date periodically. So the combination can easily go away the incorrect day showing.
It can be useful if the service told you when the gadget would next replace, and when a given tile would next replace. But it's not an enormous deal and, BloodVitals SPO2 after a little bit of head scratching, I managed to configure things such that the device updates within the early hours of the morning and the tiles are prepared for it. The price has gone up a bit since I ordered one, and you must pay an extra $20 for the Developer Edition to do fascinating issues with it. So it finally ends up just a little costly for one thing that's neat, however hardly life-changing. But perhaps you'll determine one thing interesting for it! Continuous glucose monitoring has been a factor for some time. It's a probe that sits simply inside your physique and BloodVitals SPO2 measures blood glucose levels ceaselessly. Obviously this is most useful for kind 1 diabetics, who must regulate their blood glucose manually. At this level, I would be amiss not to present a nod to the e-book Systems Medicine, which I feel most readers would find fascinating.
But CGMs have been both expensive and prescription-only. And I'm not a diabetic, type 1 or otherwise. But know-how and, more importantly, regulation have apparently marched on, and even in America I can now purchase a CGM for $50 that lasts for two weeks, over the counter. So CGM technology is now available to the mildly curious, like me. The device itself seems like a thick guitar pick, and it comes encased inside a much larger lump of plastic that has a fairly critical-trying spring inside. It takes readings every 5 minutes but only transmits each quarter-hour. You want a phone to receive the data and, if the phone shouldn't be close by, it can buffer some variety of samples and catch up when it may. The instructions say to keep the phone nearby at all times, so I did not take a look at how much it should buffer beyond an hour or so.