Wearable Hacks

837 Articles

A Timex Datalink smartwatch next to an Arduino

Arduino Keeps Your Classic Timex Datalink In Sync

March 26, 2022 by 18 Comments

The Timex Datalink was arguably the first usable smartwatch, and was worn by NASA astronauts as well as geek icons like Bill Gates. It could store alarms, reminders and phone numbers, and of course tell the time across a few dozen time zones. One of the Datalink’s main innovations was its ability to download information from your PC — either through flashing images on a CRT monitor or through a special adapter plugged into a serial port.

With CRTs thin on the ground and original serial adapters fetching ludicrous prices online, classic Datalink users today may find it hard to keep their watches in sync with their Outlook calendars. Fortunately for them, [famiclone] came up with a solution: a DIY Datalink adapter based on an Arduino. It works the same way as Timex’s serial adapter, in that it receives data through the computer’s serial port and transmits it to the watch by flashing a red LED.

Updating your watch does require the use of the original Datalink PC software, which only runs on classic operating systems like Windows 95 or 98, so you’ll need to keep a copy of such an OS running. Luckily, it has no problem with virtual machines or USB COM ports, so at least you don’t need to keep vintage PC hardware around. Then again, whipping out a 1995 Pentium laptop to update your Timex watch would make for the ultimate geek party piece.

Love classic geeky watches? Check out this featured article we did on them a few years ago. If you’re interested in using computer monitors to transmit data optically, we’ve covered a few projects that do just that.

Breathe Easy With This LED Air Sensor Necklace

March 23, 2022 by 8 Comments

When you’re building wearables and glowables, sometimes a flashy rainbow animation is all you need. [Geeky Faye] likes to go a little further, however, and built this impressive necklace that serves to inform on the local air quality. 

The necklace consists of a series of Neopixel LED strips, housed within a tidy 3D printed housing made with flexible filament. A dovetail joint makes putting on and removing the necklace a cinch. A TinyPico V2, based on the ESP32, runs the show, as it’s very small and thus perfect for the wearable application. A USB power bank provides power to the microcontroller and LEDs.

The TinyPico uses its WiFi connection to query a server fed with air quality data from a separate sensor unit. The necklace displays a calm breathing animation as standard in cool tones. However, when air quality deteriorates, it shows warmer and hotter colors in a more pointed and vibrant fashion.

It’s a neat project that shows off [Geeky Faye]’s abilities at both electronics and tasteful wearable fabrication. It’s not always easy to build projects that are both functional and comfortable to wear, but this one works on both counts. Both the 3D files for the necklace and the microcontroller firmware code is included in the GitHub repo for those keen to dive in to the nitty gritty.

We’ve seen some great necklaces over the years, including those that rely on some beautiful PCB art. Video after the break.
Continue reading “Breathe Easy With This LED Air Sensor Necklace” →

A styrofoam head wearing an electronic headband with cat ears

These Mind-Controlled Cat Ears Move With Your Mood

March 19, 2022 by 15 Comments

As any cat owner will tell you, a cat’s ears are great indicators of its state of mind: pointed forward if they want your attention, turned backwards if they’re angry, and folded down flat when they’re afraid. Humans sometimes don cat ear headbands as a fashion statement, but sitting motionless those ears are more likely to confuse a cat than to provide any meaningful communication.

[Jazz DiMauro] aims to fill that gap by designing a cat ear headband that actually responds to your emotions. It does so by continuously taking an EEG measurement and extracting the “attention” and “meditation” variables from it. Those values are then applied to a set of servos that allow two-axis motion on each 3D printed ear. The EEG readout device is an off-the-shelf MindWave headset, which outputs its sensor data through Bluetooth. An Arduino then reads out the data and drives the servos.

Turning all this into a usable wearable device was a project on its own: [Jazz] went through several iterations to find a suitable power source and wiring strategy until they settled on a pair of lithium-polymer batteries and a single flat cable. The end result looks comfortable enough to wear, and the ears’ motion looks smooth and natural. All that’s left is to test it with real cats, to find out if they can now finally understand their human’s emotions too.

We’ve featured a few moving cat ear headbands before: one that moves along with your head’s motions, and another one with manual control. Today’s EEG-powered one shows yet another application for EEGs, which have been used for anything from invoking lucid dreaming to playing beer pong. Continue reading “These Mind-Controlled Cat Ears Move With Your Mood” →

Row of white 3D printed shoes in different styles

CAD Up Some Shoes, But Don’t Start From Scratch

March 3, 2022 by 14 Comments

Nothing helps a project get off the ground better than a good set of resources, and that’s what led [DaveMakesStuff] to release his Digital Shoe Design Kit, which is a set of 3D models ready to customize into a basic running shoe.

This is exactly what is needed for people who are interested in designing a custom shoe, but perhaps not interested in modeling every element entirely from scratch. [DaveMakesStuff]’s resources allows one to mix outsoles, midsoles, uppers, and other basic shoe elements into a finished model, ready to be resized or even 3D printed if desired. The files are all in stl format, but resizing stl files is trivial, and more advanced editing is possible with mesh sculpting programs like Blender.

If the gears in your head are starting to turn and you are wondering whether it is feasible to 3D scan your feet for some experiments in DIY custom footwear, take a few minutes and read up on 3D scanning and what to expect from the process to hit the ground running.

Compressed Air Jumping Shoes Are Not For The Faint-Hearted

March 3, 2022 by 30 Comments

[Ian Charnas] has taken a short break from building things that might injure himself, by building something that could injure somebody else instead. (Video, embedded below) Well, hopefully not anyway. After working with YouTuber [Tyler Csatari] on a few ideas, [Tyler] was insistent on getting some power-assisted jumping shoes, so [Ian] set to work mounting some compressed-air powered pistons to a pair of walking shoes. With a large backpack housing the 200 PSI air cylinder, control valves and timers. The whole affair looks solidly constructed, if a little ungainly, but does seem to work surprisingly well.

After some initial calculations of how much force each piston could exert before risking leg injury, he found that whilst it did work, to an extent, the pressure required was beyond the capability of the compressor they had on hand. After a shopping trip, a bigger compressor was located, but that still needed a modification to get anywhere near its maximum 200 psi rating. The thing is, that modification was to bypass the regulator and the safety valve, and this is definitely something you don’t want to be making a habit of. Compressed air systems like this can hold quite a bit of an explosion potential if pushed beyond reasonable limits, and care needs to be taken to keep things within safe bounds.

Cost-wise, [Ian] does mention a figure of around $3,000 USD making it a bit of a pricey project, but hey a YouTuber’s paying the bill, so it must just be a drop in the ocean for them?

Just to illustrate how useful compressed air is as a method of storing energy, here’s a compressed-air powered helicopter, and a 3D printed wankel rotary engine, which must’ve been tough to dial in and get working!

Continue reading “Compressed Air Jumping Shoes Are Not For The Faint-Hearted” →

Three pendants that the article is describing, on a drafting mat.They're heart-shaped red PCBs with LEDs all around its perimeter, two CR2032-like batteries in its center.

Heart-Shaped Heartwarming Valentine’s Day Pendant

January 24, 2022 by No comments

This is no ordinary heart-shaped PCB pendant project! To us, it’s also symbol representing the striking amount of love that [SaltyPaws] has put into its design and documentation. He tells us that he designed it for the two daughters he is raising, as an electronics and general STEAM introduction – with outstanding educational and aesthetic qualities, giving insights into a wide range of topics while looking . The PCB is mostly through-hole, making for easy soldering and quick return on the effort investment. The project is thought-out beyond the PCB, however – this pendant is designed to be wearable day-to-day, which is why it’s accompanied by a 3D-printed frame, protecting its wearer from sharp PCB edges and through-hole lead ends!

Open-sourcing things is a gift, and today, we are also the recipients. [SaltyPaws] has open-sourced everything involved – PCB files, 3D cover files, firmware, BOM, everything you would need to build your own version. All of this is in a GitHub repository, with detailed sourcing and assembly instructions in the README.md – we couldn’t ask for more! If you have loved ones that would take delight in putting such a pretty pendant together, you have about a week to order the PCBs – after that, Chinese New Year will likely thwart your plans!

Looking for more accessories that double as electronics projects? We’ve covered a wide variety, even when it comes to pendants alone – check out this edge-lit fluorescent acrylic educational Maker Faire accessory, or this circuit sculpture BEAM-inspired bird-imitating one, or this tiny SAMD21-powered pendant with an IPS LCD!

Silicone Devices: DIY Stretchable Circuits

January 23, 2022 by 12 Comments

Flexible circuits built on polyimide film are now commonplace, you can prototype with them at multiple factories, at a cost that is almost acceptable to your average hacker. Polyimide film is pretty tough for something so thin, but eventually it will tear, and with larger components, bend radii are quite restricted. But what about stretchable circuits, as in circuits you can flex, twist and stretch? Let us introduce silicone devices. A research group from Hasselt University, Belgium, have been prototyping making truly flexible, silicone-based circuit substrates, managing to integrate a wide range of SMT component types with a dual layer interconnect, with vias and external contacts.

It should be possible to reproduce the process using nothing more special than your average Makerspace CO2 laser cutter, and a couple of special tools that can be easily made — a guide for that is promised — it is purely a matter of gathering a few special materials, and using off-cuts you have lying around for the rest. The interconnect uses Galinstan, which is a low melting point alloy of gallium, indium, and tin. Unfortunately, this material is fairly expensive and cannot be shipped by air due to the gallium content, without specialised handling, at considerable expense. But that aside, other than some acrylic sheets, some vinyl, copper foil and a few sprays, nothing is beyond reach.

The construction process is reverse to what we normally see, with the components and copper contact plates placed first, on to a primed vinyl sheet. This sheet is laser marked with the component outlines to enable them to be corrected placed. Yes, that’s right, they’re using a laser cutter to mark vinyl, a chlorine-containing plastic. Hold on to that thought for a bit.

Insulating layers and substrate layers are constructed by blade-coating with a layer of clear silicone. Interconnect layers are formed by sticking a fresh vinyl sheet onto the exposed contacts and laser cutting just though it to expose the pads and the interconnect traces. Next the fancy Galinstan is applied by brush and the vinyl stencil removed. Rinse and repeat for the next layer of insulating silicone, more circuit traces, then use the laser cutter to precisely etch through the via regions to allow more metalisation to be added. Finally a coating of silicone is applied over the whole assembly, the laser is again used to etch the silicone away from the contact pads, and with a little solder tinning of these, you’re done. Simple, if only our Makerspaces didn’t have rules against laser cutting vinyl.

This was clearly a very brief overview, here is a very detailed instructables guide ready for you, as well as a formal research paper, detailing why this came about and why you might want to try this yourself.

If you’re into custom wearables, you might remember this earlier piece about silicone circuits, and this one weird organic-looking thing from the same time-frame.

Continue reading “Silicone Devices: DIY Stretchable Circuits” →