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.
We’d never criticize somebody for coming up with a creative way to save a few bucks. In truth, pickings would be pretty slim around here if we deleted every project or hack where cost savings was a prime motivator. That being said, there’s still some things you should probably spend a few extra dollars on. You know, the essential things in life that you need to know will be safe and reliable, like your car and…your flamethrower.
At the heart of this flamethrower is a solenoid valve recovered from a Glade air freshener. Rather than spraying out the smell of lilacs, this valve has found a new purpose in life by squirting out butane from a pressurized can. The butane is then ignited by a spark gap made up two nails connected to a 300 kV boost coil.
[Steve] designed the frame of this creation in OpenSCAD, and printed it out in a single piece. It holds the butane can and solenoid in position, as well as keeping the nails in the proper orientation for the spark gap to function. Admittedly the head of his printed flamethrower does look very cool, but if there was ever a situation where you should be suspect of the heat tolerance of 3D printed plastic, a flamethrower is probably it.
What’s noticeably lacking of course is any method to keep the flame from potentially traveling back up through the valve and into the butane can. The high-speed flow coming out of the nozzle is probably enough to keep that from happening, but we still wouldn’t feel comfortable strapping his device to our wrist as-is.
Even when you bear a passing resemblance to the paranoid Auror of the Harry Potter universe, you still really need that wonky and wandering prosthetic eye to really sell that Mad-Eye Moody cosplay, and this one is pretty impressive.
Of course, there’s more to the [daronjay]’s prosthetic peeper than an eBay doll’s eye. There’s the micro-servo that swivels the orb, as well as a Trinket to send the PWM signal and a pocket full of batteries. The fit and finish really tie it together, though, especially considering that it’s made from, well, garbage — a metal food jar lid, a yogurt cup, and the tube of a roll-on antiperspirant. Some brass screws and a leather strap evoke the necessary Potter-verse look, and coupled with what we assume are prosthetic scars, [daronjay] really brings the character to life. We think it would be cool to have the servo eye somehow slaved to the movements of the real eye, with a little randomness thrown in to make it look good.
Over the years, [Admar] has discovered that any e-textile project requiring more than a few connections is ripe for some kind of textile-friendly multi-point connector. Through trial and error, he designed a robust solution for use with an embroidery machine. The wires are made from conductive thread and soldered to a row of male header pins to make the transition out of fiber space. This transition requires solder, which quickly gets interesting when coupled with a fabric substrate and no solder mask. We wonder if spraying on mask beforehand would help, or if it would just soak in and stain and get in the way.
You can see the connector in practice in [Admar]’s capacitive multi-touch demo video after the break. He has stacked two pieces of fabric, each with a wire bus made of conductive threads, with the traces at right angles. Both sensors are wired to a Cypress PSoC5 to create a sensor matrix, and then to a laptop for visualization purposes. As his fingers approaches the fabric, the bar graphs roar upward to show increased capacitance. Once he makes contact, each finger appears as a yellow dot illustrating pressure.
While the current generation of smartwatches have only been on the market for a few years, companies have been trying to put a computer on your wrist since as far back as the 80s with varying degrees of success. One such company was Seiko, who in 1984 unveiled the UC-2000: a delightfully antiquated attempt at bridging the gap between wristwatch and personal computer. Featuring a 4-bit CPU, 2 KB of RAM, and 6 KB of ROM, the UC-2000 was closer to a Tamagotchi than its modern day counterparts, but at least it could run BASIC.
With extremely limited published information, and no toolchain, [Alexander] did an incredible job of figuring out the assembly required to interact with the hardware. Along the way he made a number of discoveries which set his plans back, such as the fact that there is no way to directly control individual pixels on the screen; all graphics would have to be done with the built-in symbols.
The culmination of all this hard work? Playing Tetris, naturally. Though [Alexander] admits that limitations of the device’s hardware meant the game had to be simplified a bit, he’s almost certainly having more fun than any of the UC-2000’s original owners did with this device. He’s setup a GitHub repository for anyone who wishes to join him in this brave new world of vintage wrist computing.
Sometimes great projects keep evolving. [Bithead942] built himself an R2-D2 to accompany him when he goes a-trooping — but something didn’t feel quite right. Turns out, R2 was missing its signature beeping banter, so he made it more contextually responsive by implementing a few voice commands.
[Bithead942]’s main costume is that of an X-Wing pilot, and the replica helmet works perfectly; it already has a fake microphone — easily replaced with a working model — and the perfect niche to stash the electronics in the ‘mohawk.’
Even though the helmet has the perfect hiding spot for a circuit, space is still at a premium. Services like Alexa tend to be pretty accurate, but require WiFi access — not a guarantee on the convention floor. Instead, [bithead942] found that the EasyVR Shield 3.0 voice recognition board provided a suitable stand-in. It needs a bit of training to work properly(cue the montage!), but in the end it compares fresh audio commands to the ‘training’ files it has stored, and if there’s a match, triggers a corresponding serial port. It’s not perfect, but it most certainly works!
The wristwatch was once an absolute necessity, as much fashion statement as it was a practical piece of equipment. Phones in our pockets (and more often than not, in our faces) replaced the necessity of the wristwatch for the majority of people, and the fashion half of the equation really only interests a relatively small subset of the population. The end result is that, aside from the recent emergence of smartwatches and fitness trackers, walking down the street it’s fairly unlikely you’ll see many people wearing a traditional watch.