A Backpack That Measures Your Heart Rate

It’s interesting to see the different form-factors that people utilize for their portable biometric sensors. We’re seeing heart rate monitors and other biometric sensors integrated into watches, earbuds, headbands, sports bras, and all sorts of other garments and accessories. [Gabi] took an intriguing approach, integrating an electrocardiogram (ECG) into a backpack. This type of heart rate project is pretty popular here on Hackaday, so it was great running across [Gabi’s] design during our daily perusing for the new and exciting.

[Gabi] used an Adafruit FLORA, a BLE module, an ECG sensor from Bitalino, a few other ancillary components, and, of course, a backpack. We appreciate that she walked us through the list of stumblingblocks she came across and how she got around them. So much of the time in our excitement to share our projects we remove the gory details and only present the finished project when really, we learn most from all the things that didn’t work more so than the things that did. Finally, [Gabi] walks through the intricacies of the threading and the particular placement of the snap connectors to attach the circuit to the ECG electrodes. Things get pretty tricky, but luckily [Gabi] documents her project pretty meticulously with schematics, pictures, and early notice of pitfalls.

[Gabi] made sure to remind her readers that this is a prototype, not a medical device. She also brought up electrical safety. Biometric devices such as ECGs need to include a strict set of isolation circuits to prevent potential harm to the user. Fortunately, there are a few well-characterized methods to accomplish this.

So thanks for a really cool project, [Gabi], and to our readers, why not enjoy some of our other ECG projects while you’re at it?

Magnets Make Prototyping E-Textiles A Snap

How do you prototype e-textiles? Any way you can that doesn’t drive you insane or waste precious conductive thread. We can’t imagine an easier way to breadboard wearables than this appropriately-named ThreadBoard.

If you’ve never played around with e-textiles, they can be quite fiddly to prototype. Of course, copper wires are floppy too, but at least they will take a shape if you bend them. Conductive thread just wants lay there, limp and unfurled, mocking your frazzled state with its frizzed ends. The magic of ThreadBoard is in the field of magnetic tie points that snap the threads into place wherever you drape them.

The board itself is made of stiff felt, and the holes can be laser-cut or punched to fit your disc magnets. These attractive tie-points are held in place with duct tape on the back side of the felt, though classic double-stick tape would work, too. We would love to see somebody make a much bigger board with power and ground rails, or even make a wearable ThreadBoard on a shirt.

Even though [chrishillcs] is demonstrating with a micro:bit, any big-holed board should work, and he plans to expand in the future. For now, bury the needle and power past the break to watch [chris] build a circuit and light an LED faster than you can say neodymium.

The fiddly fun of e-textiles doesn’t end with prototyping — implementing the final product is arguably much harder. If you need absolutely parallel lines without a lot of hassle, put a cording foot on your sewing machine.

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Fabric(ated) Drum Machine

Some folks bring out an heirloom table runner when they have company, but what if you sewed your own and made it musical? We’d never put it away! [kAi CHENG] has an Instructable about how to recreate his melodic material, and there is a link to his website, which describes his design process, not just the finished product. We have a video below showing a jam session where he exercises a basic function set.

GarageBand is his DAW of choice, which receives translated MIDI from a Lilypad. If you don’t have a Lilypad, any Arduino based on the ATmega328P chip should work seamlessly. Testing shows that conductive threads in the soft circuit results in an occasional short circuit, but copper tape makes a good conductor  at the intersections. Wide metallic strips make for tolerant landing pads beneath modular potentiometers fitted with inviting foam knobs. Each twist controls a loop in GarageBand, and there is a pressure-sensitive pad to change the soundset. Of course, since this is all over MIDI, you can customize to your heart’s content.

MIDI drums come in all shapes and sizes, from a familiar game controller to hand rakes.

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Social Media Jacket Puts Your Likes On Your Sleeve

The great irony of the social media revolution is that it’s not very social at all. Users browse through people’s pictures in the middle of the night while laying in bed, and tap out their approval with all the emotion of clearing their spam folder. Many boast of hundreds or thousands of “friends”, but if push came to shove, they probably couldn’t remember when they had last seen even a fraction of those people in the real world. Assuming they’ve even met them before in the first place. It’s the dystopian future we were all warned about, albeit a lot more colorful than we expected.

But what if we took social media tropes like “Likes” and “Follows”, and applied them to the real world? That’s precisely what [Tuang] set out to do with the “Social Touch Suit”, a piece of wearable technology which requires a person actually make physical contact with the wearer to perform social engagements. There’s even a hefty dose of RGB LEDs to recreate the flashy and colorful experience of today’s social media services.

Every social action requires that a specific and deliberate physical interaction be performed, which have largely been designed to mimic normal human contact. A pat on the shoulder signifies you want to follow the wearer, and adding them as a friend is as easy as giving a firm handshake. These interactions bring more weight to the decisions users make. For example, if somebody wants to remove you as a friend, they’ll need to muster up the courage to look you in the eye while they hit the button on your chest.

The jacket uses an Arduino to handle the low level functions, and a Raspberry Pi to not only provide the slick visuals of the touch screen display, but record video from the front and rear integrated cameras. That way you’ve even got video of the person who liked or disliked you. As you might expect, there’s a considerable energy requirement for this much hardware, but with a 5200 mAh LiPo battery in the pocket [Tuang] says she’s able to get a run time of 3 to 4 hours.

Considering how much gadgetry is packed into it, the whole thing looks remarkably wearable. We wouldn’t say it’s a practical piece of outerwear when fully decked out, but most of the electronic components can be removed if you feel like going low-key. [Tuang] also points out that for a garment to be functional it really needs to be washable as well, so being able to easily strip off the sensitive components was always an important part of the design in her mind.

The technology to sensors wearable and flexible is still largely in its infancy, but we’ve very excited to see where it goes. If projects like these inspire you, be sure to check out the presentation [Kitty Yeung] gave at the Hackaday Supercon where she talks about her vision for bespoke wearable technology. Continue reading “Social Media Jacket Puts Your Likes On Your Sleeve”

ETextile Spring Break Tackles Signal Blocking, Audio Generation, And Radio Transmissions

Finding a killer application for e-textiles is the realm of the hacker and within that realm, anything goes. Whether it’s protecting your digital privacy with signal shielding, generating audio with a wearable BeagleBone or 555 timer, or making your favorite garment into an antenna, the eTextile Spring Break is testing out ways to combine electronics and fabric.

You may be asking yourself “What are e-textiles good for?”. Well, that’s an excellent question and likely the most common one facing the industry today. I’m afraid I won’t be able to give a definitive answer. As an e-textile practitioner, I too am constantly posing this question to myself. There’s an inherently personal nature to fabric worn on the body and to our electronic devices that makes this answer elusive. Instead of trying to fabricate some narrow definition, what I offer is a look at topics of interest, material experimentation, and technical exploration through the lens of a week-long event held recently in New York called eTextile Spring Break.

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Bumblebee Breakout, A DIY Wearable Connector

The practice of developing wearable electronics offers a lot of opportunity for new connector designs and techniques for embedding electronics. Questions like these will eventually come up: How will this PCB attach to that conductive fabric circuit reliably? What’s the best way to transition from wire to this woven conductive trim? What’s the best way to integrate this light element into this garment while still maintaining flexibility?

Mika Satomi and Hannah-Perner Wilson of Kobakant are innovators in this arena and inspire many with their prolific documentation while they ask themselves questions similar to these. Their work is always geared towards accessibility and the ability to recreate what they have designed. Their most recent documented connector is one they call the Bumblebee Breakout. It connects an SMD addressable RGB LED, such as Adafruit’s Neopixel, to a piece of side glow fiber optic 1.5mm in diameter. On a short piece of tubing, the four pads of the SMD LED are broken out into four copper rings giving it the look of a striped bumblebee. To keep from shorts occurring while wrapping the copper tape contacts around the tube, they use Kapton tape to isolate each layer as they go.

This connector was originally created to be used in a commission they did out of Koba, their e-textile tailor shop located in Berlin. Fiber optics were applied to jackets for a performance called “All Your Base Are Belong To Us” produced by the Puppetry Department of the Hochschule für Schauspielkunst Ernst Busch.

Peruse more e-textiles techniques and learn how to build a connector transitioning from an embroidered thread bus to a wire and how to knit solderable circuit boards. And make sure to click around Kobakant’s website, it’s full of e-textile DIY tutorials! 

Your Next Wearable May Not Need Electricity

What if you could unlock a door with your shirtsleeve, or code a secret message into your tie? This could soon be a thing, because researchers at the University of Washington have created a fabric that can store data without any electronics whatsoever.  The fabric can be washed, dried, and even ironed without losing data. Oh, and it’s way cheaper than RFID.

By harnessing the ferromagnetic properties of conductive thread, [Justin Chen] and [Shyam Gollakota] have  proved the ability to store bit strings and 2D images through magnetization. The team used an embroidery machine to lay down thread in dense strips and patches, and then coded in ones and zeros by rubbing the threads with N and S neodymium magnets.

They didn’t use anything special, either, just this conductive thread, some magnets, and a Nexus 5 to read the data. Any phone with a magnetometer (so, most of them) could decode this type of binary data. The threads stay reliably magnetized for about a week and then begin to weaken. However, their tests proved that the threads can be re-magnetized over and over.

The team also created 2D images with magnets on a 9-patch made of conductive fabric. The images can be decoded piecemeal by a single magnetometer, or all at once by an array of them. Finally, the team made a glove with a magnetized patch of thread on the fingertip. They were able to get the phone to recognize six unique gestures with 90% accuracy, even with the phone tucked away in a pocket. See it in action in their demo video after the break.

Magnetic memory is certainly not a new concept. But for the wearable technology frontier, it’s a novel one.

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