Live Glucose Monitoring With The Apple Watch

June 6, 2022 by 27 Comments

There has been a rumor that Apple is working on a glucose monitoring solution for the Apple watch. [Harley] decided not to wait and managed to interface an Abbot FreeStyle Libre sensor with the Apple watch. The sensor doesn’t directly read glucose continuously, but it does allow for more frequent reading which can help diabetic patients manage their blood sugar levels. However, as part of the hack, [Harley] effectively converts the meter to a continuous-reading device, another bonus.

The trick is to add a Bluetooth transmitter to the NFC sensor. Using a device called a MiaoMiao, the task seems pretty simple. The MiaoMaio is small, waterproof, and lasts two weeks on a charge, which is longer than the sensor’s life. Honestly, this is the hack since once you have the data flowing over Bluetooth, you can process it in any number of ways including using an app on the Apple watch.

It isn’t perfect. There’s a slight lag with readings due to the way the sensor works. However, you usually don’t care as much about the absolute value of your glucose (unless it is very high or very low). You are usually more interested in the slope of the change. This data is more than good enough for that.

In fact, the most complex part of this seems to be the watch app. It might be less work to feed the data to a machine learning model and let AI guide your insulin injections. Something to think about.

We have a keen interest in glucose monitoring around here and we know why it is so darn hard. Honestly, the idea of pushing glucose meter data to a watch isn’t new, but this is a well-done implementation with a lot of possibilities.

A Simple Binary Coded Decimal Watch

May 10, 2022 by 15 Comments

Analog and LCD watches are both useful designs, but ultimately are mainstream timepieces. Using a binary watch is an easy way to set one’s self apart as a tech enthusiast, while impressing your hacker friends to boot.

One such build comes to us from [vishalsoniindia], and it uses a single bare PCB which is designed to mate directly to a traditional watch strap. The single tactile button on board is used to activate the watch, showing the current time in hours and minutes in binary-coded decimal on the watch’s LEDs. Long-pressing the button puts the watch in setting mode to correct the time as needed.

The watch relies on an ATtiny85 microcontroller, a lightweight and compact design which is more than powerful enough to run a simple watch. It’s paired with a 74HC595 shift register to run all the LEDs from a minimum number of pins, and there’s also a TP4056 charging circuit on board to keep the lithium-polymer battery topped off.

A project like this is a great way to learn all manner of basic electronics skills, from PCB design, to SMD soldering and even working with basic logic parts like shift registers. As a bonus, you get a cool watch out of it to boot.

We’ve seen some similar designs over the years, as varied as the hackers that build them. Video after the break.

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Training Doppler Radar With Smart Watch IMUs Data For Activity Recognition

April 30, 2022 by 3 Comments

When it comes to interpreting sensor data automatically, it helps to have a large data set to assist in validating it, as well as training when it concerns machine learning (ML). Creating this data set with carefully tagged and categorized information is a long and tedious process, which is where the idea of cross-domain translations come into play, as in the case of using millimeter wave (mmWave) radar sensors to recognize activity of e.g. building occupants with the IMU2Doppler project at Smash Lab of Carnegie Mellon University.

The most commonly used sensor type when it comes to classifying especially human motion are inertial measurement units (IMU) such as accelerometers and gyroscopes, which are found in everything from smartphones to smart watches and fitness bands. For these devices it’s common to classify measurement patterns as matches a particular activity, such as walking, jogging, or brushing one’s teeth. This makes them both well-defined and very accessible.

As for why a mmWave-based Doppler radar would be preferred for monitoring e.g. building occupants is the privacy aspect compared to using cameras, and the inconvenience of equipping people with a body-worn IMU. Using Doppler radar it would theoretically be possible for people to track activities within their own home, as well as in a medical setting to ensure patients are safe, or at a gym to track one’s performance, or usage of equipment. All without the use of cameras or personal sensors. In the past, we’ve seen a similar approach that used targeted laser beams.

As promising as this sounds, at this point in time the number of activities that are recognized with reasonable accuracy (~70%) is limited to ten types. Depending on the intended application this may already be sufficient, though as the published paper notes, there is still a lot of room for growth.

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Watch A Complete Reflector Telescope Machined From A Single Block Of Glass

April 21, 2022 by 16 Comments

If this is the easy part of making a complete reflector telescope from a single piece of glass, we can’t wait to get a load of the hard part!

A little backstory may be in order for those who don’t follow [Jeroen Vleggaar]’s Huygens Optics channel on YouTube. A few months ago, he released a video discussing monolithic telescopes, where all the reflective and refractive surfaces are ground into a single thick block of glass. Fellow optical engineer [Rik ter Horst] had built a few tiny monolithic Schmidt-Cassegrain reflectors for use in cube sats, so [Jeroen] decided to build a scaled-up version himself.

The build starts with a 45 mm thick block of crown glass, from which a 50 mm cylinder is bored with a diamond hole saw. The faces of the blank are then ground into complex curves to reflect incoming light, first off the parabolic rear surface and then onto the hyperbolic secondary mirror ground into the center of the front face. A final passage through a refracting surface in the center of the rear face completes the photons’ journey through the block of glass, squeezing a 275 mm focal length into a compact package.

All this, of course, vastly understates the work required to pull it off. Between the calculations needed to figure out the surface shapes in the first place to the steps taken to machine a famously unforgiving material like glass, every step is fraught with peril. And because the design is monolithic, any mistakes mean starting all over again. Check out the video below and marvel at the skills needed to get results like this.

What strikes us most about [Jeroen]’s videos is the mix of high-tech and age-old methods and materials used in making optics, which we’ve seen him put to use to make everything from tiny Tesla valves to variable-surface mirrors.

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A Tshwatch on a table

TshWatch Helps You Learn More About Yourself

April 3, 2022 by 13 Comments

TshWatch is a project by [Ivan / @pikot] that he’s been working on for the past two years. [Ivan] explains that he aims to create a tool meant to help you understand your body’s state. Noticing when you’re stressed, when you haven’t moved for too long, when your body’s temperature is elevated compared to average values – and later, processing patterns in yourself that you might not be consciously aware of. These are far-reaching goals that commercial products only strive towards.

At a glance it might look like a fitness tracker-like watch, but it’s a sensor-packed logging and measurement wearable – with a beautiful E-Ink screen and a nice orange wristband, equipped with the specific features he needs, capturing the data he’d like to have captured and sending it to a server he owns, and teaching him a whole new world of hardware – the lessons that he shares with us. He takes us through the design process over these two years – now on the fifth revision, with first three revisions breadboarded, the fourth getting its own PCBs and E-Ink along with a, and the fifth now in the works, having received some CAD assistance for battery placement planning. At our request, he has shared some pictures of the recent PCBs, too!

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This WeeΚ In Security: Hackerman, Twitter’s Best, And Signs To Watch Out For

April 1, 2022 by 6 Comments

[Editor’s note: There is a second, fake iteration of this column out today. This is obviously the real column.]

First off, there’s an amazing video tutorial from [Hackerman], embedded below the break. It’s a beginners guide to temporal displacement through GPU accelerated, cellular-connected partition board. The central flaw that makes this possible is a segmentation violation, accessible through a mode 6 cursor address reset. Watch out, though, because many mainframes actually have a core terminal capable of shutting such an attempt out of the grid altogether.

It’s a great guide, and definitely worth a watch if temporal security tickles your fancy. Watch out, though, because everyday objects can apparently act as bridges, infecting even users with temporal effects.

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Watching A Spacewalk In Real Time

March 31, 2022 by 6 Comments

If you go to, say, a football game, you probably don’t get to see as much of the game as close as you do when you stay home and watch on TV. But there’s something about being there that counts. That’s probably how [Sebastian Voltmer] feels. While we’ve all seen video of astronauts and cosmonauts spacewalking, [Sebastian] managed to take a snapshot of a pair of spacewalkers from his telescope.

Of course, this wasn’t your ordinary department store Christmas gift telescope. The instrument was a Celestron 11 inch EdgeHD Schmidt-Cassegrain telescope on a very expensive GM2000 HPS mount. An ASI290 planetary camera took the shot. You can see the gear and more about the photos in the video below.

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