Infant is wearing sensor vest as she is held by her mom. ECG, respiration, and accelerometry data is also showing.

Open Source Wearables For Infants

August 9, 2022 by Orlando Hoilett 8 Comments

We’ve seen plenty of hacks that analyze biometric signals as measures of athletic performance, but maybe not as many hacks that are trying to study behavior. Well, that’s exactly what developmental psychologists at Indiana University and the University of East Anglia have done with their open-source, wireless vest for measuring autonomic function in infants.

Their device includes a number of components we’ve seen already. There is an HC-05 Bluetooth module, AD8232 electrocardiography (ECG) analog front-end, LIS3DH 3-axis accelerometer, MCP73831 LiPo charger, a force-sensitive resistor for measuring respiration, and a Teensy microcontroller. Given how sensitive an infant’s skin can be, they opted for fabric electrodes for the ECG instead of those awful sticky ones that we’re accustomed to. They then interfaced the conductive fabric with copper plates using snap fasteners (or press studs or snap buttons, whichever terminology you’re more familiar with). The copper plates were connected to the circuit board using standard electrical wire. Then, they embedded the sensors into a vest they sewed together themselves. It’s basically a tiny weighted vest for infants but it seems well-padded enough to be somewhat comfortable.

They did a short test analyzing heart and breathing rates during a period of “sustained attention,” basically when you’re quietly fixated on a single object or activity for a period of a few minutes or longer. They were really pleased with the vest’s ability to collect consistent data and noted that heart and respiratory rate variability decreased during the sustained activity test, which was an expected outcome. Apparently, when you’re pretty fixated on a singular task, your body naturally calms down, so to speak, and the variability in some of your physiological responses decreases. Well, unless someone slowly walks up behind you and pinches you, of course.

They provided detailed instructions for recreating the vest, so be sure to check those out. They probably want their device to look a lot less than body armor though. Maybe the Sewbo can help them out with their next iteration.

The Casio Smartwatch You Never Had

July 20, 2022 by Jenny List 26 Comments

In a way, you have to feel a bit sorry for the engineers at Casio. They can produce the most advanced digital watches ever to grace the wrist, but their work will forever be associated with one of their more lowly creations. The Casio F91 is the archetypal digital watch — it’s affordable, it’s been in production since the Ark, it does the job so well that it’s become a design classic, and it remains a very tough act to follow.

If it has a flaw though, it’s that the functions of a watch from 1989 are very basic. Wouldn’t it be nice if a Casio F91 could be a modern smartwatch! Well thanks to [Pegor] it can, with a complete re-engineering of the classic watch’s internals. Now the simple classic timepiece is fully up-to-date!

All the Casio internals are removed, and a new movement holder supports a fresh PCB with an OLED display mounted via a flexible sub-PCB. The brains comes courtesy of a Texas Instruments CC2640 BLE microcontroller. This gives it a 15-day battery life, which is nothing like what the original watch would have but compares favorably to smartwatches. He admits that the software needs some work, but with hardware this well-executed we hope that others can contribute some improvements.

This is probably the most impressive F91 hack we’ve seen, but it’s by no means the first revamped Casio we’ve shown you.

A Commodore 64 running a smartwatch link program

The Commodore 64 Smartwatch Can Now Sync With Your Commodore 64 Desktop

July 18, 2022 by Robin Kearey 5 Comments

If you’ve got a smartwatch on your wrist, chances are you’ve also got a device nearby that links up with it. Most modern watches will happily sync with Android devices or iPhones, and some will also talk to Windows PCs. But what if you’re running an alternative OS? Something like, say, Commodore BASIC? In that case, you might want to check out [Nick Bild]’s latest project, which lets you to sync your smartwatch to your Commodore 64.

Sadly, you can’t just use any old smartwatch: the project is an extension of [Nick]’s Commodore 64 Smartwatch that we featured earlier. This watch can run Commodore 64 programs thanks to a custom software stack, but like most typical smartwatches also includes an accelerometer that counts your steps. Syncing the step counter to your computer is straightforward: after you come home from your daily run, you simply tap “sync” on the watch, enter LOAD"SYNC.PRG",8,1 on your Commodore 64, and the computer will show your total step count.

The C64 watch communicates with the host computer through a built-in infrared port. The classic Commodore computers don’t have an IR receiver, so [Nick] built one himself using an Arduino Micro hooked up to the C64’s User port. A custom program reads out the data and shows the step count on the screen.

Although the feature set of this app is a bit limited, [Nick]’s project demonstrates how the good old Commodore 64 can still perform useful tasks in today’s world. Not that we needed much reminding: after all, we’ve even seen it run AI applications using TensorFlow Lite.

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TshWatch Helps You Learn More About Yourself

April 3, 2022 by Arya Voronova 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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Cheating A Pedometer The Easy Way

November 20, 2021 by Lewin Day 9 Comments

These days, pedometers are integrated into just about every smartwatch on the market, and some of the dumber ones too. Tracking step counts has become a global pastime, and at times, a competitive one. However, any such competition can easily be gamed, as demonstrated by [Luc Volders].

Generally, all it takes to fool a basic pedometer is a gentle rhythmic jiggling motion of some sort. Cheaper devices will even register steps with little more than vague shaking.

[Luc] exploited this with basic machinery. A servo’s output shaft is fitted with a 3D printed cylinder, sized to allow a smartwatch to be attached as if to a wrist. Then, a Raspberry Pi Pico simply rocks the servo back and forth at regular intervals, and the watch begins counting these ersatz steps. Looking at the project as a whole, we’re betting [Luc] took some inspiration from old-fashioned automatic watch winders.

It’s hard to envision an important application for this technology. However, if one is in a friendly competition with friends who don’t scrutinize the results too closely, this would be an easy way to win.

Alternatively, consider building a pedometer to track your hamster’s exercise regime. If you’ve got your own exercise hacks on the go, drop us a line!

This Smart Watch Keeps An Eye On Ambient CO2 Levels

October 30, 2021 by Lewin Day 20 Comments

Human respiration takes in oxygen and in turn, we exhale carbon dioxide. Thus, an uptick of carbon dioxide levels around us can indicate we’re in the presence of other humans, and also, perhaps, the pathogens they carry. To explore this phenomenon, [C Scott Ananian] developed a mod for the Watchy open-source smartwatch, which lets it detect carbon dioxide.

The idea behind the build is simple. If you’re around increased CO2 levels, it may be because you’re surrounded by people, and thus more likely to be exposed to COVID-19. To detect CO2, the watch relies on a Sensiron SCD40 or SCD41 sensor. This is read by the Watchy’s ESP32 microcontroller, and results are graphed on the watch’s e-Paper display. The Watchy is also given a nice new aluminum case to fit the additional hardware.

It’s cool having a graph on your wrist of the ambient concentration of CO2, and at the very least, it could make a good talking point next time you’re at a particularly boring party. You’ll also be more than ready to advise other partygoers if the carbon dioxide level is reaching dangerous levels.

We’ve seen similar builds before, which are useful not only for pandemic safety but also for monitoring if you have any leaks from CO2 storage in the house. If you’ve been working on your own ways to track dangerous gases, be sure to drop us a line!

PineTime Smartwatch And Good Code Play Bad Apple

October 16, 2021 by Brian McEvoy 11 Comments

PineTime is the open smartwatch from our friends at Pine64. [TT-392] wanted to prove the hardware can play a full-motion music video, and they are correct, to a point. When you watch the video below, you should notice the monochromatic animation maintaining a healthy framerate, and there lies all the hard work. Without any modifications, video would top out at approximately eight frames per second.

To convert an MP4, you need to break it down into images, which will strip out the sound. Next, you load them into the Linux-only video processor, which looks for clusters of pixels that need changing and ignores the static ones. Relevant pixel selection takes some of the load off the data running to the display and boosts the fps since you don’t waste time reminding it that a block of black pixels should stay the way they are. Lastly, the process will compress everything to fit it into the watch’s onboard memory. Even though it is a few minutes of black and white pictures, compiling can take a couple of hours.

You will need access to the watch’s innards, so hopefully, you have the developer kit or don’t mind cracking the seal. Who are we kidding, you aren’t here for intact warranties. The video resides in the flash chip and you have to transfer blocks one at a time. Bad Apple needs fourteen, so you may want to practice on a shorter video. Lastly, the core memory needs some updating to play correctly. Now you can sit back and…watch.

Pine64 had a rough start with the single-board computers, but they’re earning our trust with things like soldering irons and Google-less Linux mobile phones.

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