[Gautchh] wanted to make something nice for his girlfriend. Being the DIY enthusiast he is, he thought a hand-made gift would resonate with her better than something he could pick up from the store. Enter NeckLight, a glow in the dark PCB necklace. He was first inspired by another project he ran across on Instructables, then decided to put his own little spin on the design. It’s cool how that works. Interestingly enough, it was his first time using Fusion 360, but you probably wouldn’t know that if you took a look at the results.
Aside from soldering, the trickiest part of this project was trying to get the LED intensities just right. [Gautchh] found the best way to do this was experimentally by testing each LED color with a series of resistors. He wanted to ensure he could get the color intensity and the LED current just right. Finally, with a touch of acetone, he was done (though he might want to try some alternatives to acetone next time).
[Gautchh] also thinks that this project would be a really nice way for beginners to learn surface mount (SMD) soldering. We’ve seen a few cool SMD LED projects before. Who could forget those competitive soldering challenges over at DEF CON?
Anyway. Thanks, [Gautchh]. We hope your girlfriend, and your dog, enjoyed their gifts.
Here at Hackaday, we’re always enthralled by cool biohacks and sensor development that enable us to better study and analyze the human body. We often find ourselves perusing Google Scholar and PubMed to find the coolest projects even if it means going back in time a year or two. It was one of those scholarly excursions that brought us to this nifty smart bandage for monitoring wound healing by the engineers of FlexiLab at Purdue University. The device uses an omniphobic (hydrophobic and oleophobic) paper-based substrate coupled with an onboard impedance analyzer (AD5933), an electrochemical sensor (the same type of sensor in glucometers) for measuring uric acid and pH (LMP91000), and a 2.4 GHz antenna for wirelessly transmitting the data (nRF24L01). All this is programmed with an Arduino Nano. They even released their source code.
To detect uric acid, they used the enzyme uricase, which is very specific to uric acid and exhibits low cross-reactivity with other compounds. They drop cast uric acid onto a silver/silver chloride electrode printed on the omniphobic paper. Similarly, to detect pH, they drop cast a pH-responsive polymer called polyaniline emeraldine salt (PANI-ES) between two separate silver/silver chloride electrodes. All that was left was to attach the electrodes to the LMP91000, do a bit of programming, and there they were with their own electrochemical sensor. The impedance analyzer was a bit simpler to develop, simply attaching un-modified electrodes to the AD5933 and placing the electrodes on the wound.
Wearables are kind of a perplexing frontier for electronics. On the one hand, it’s the best possible platform for showing off a circuit everywhere you go. On the other hand, the whole endeavor is fiddly because the human body has no straight lines and moves around quite a bit. Circuits need to be flexible and comfortable. In other words, a wearable has to be bearable.
It’s a small and portable roll-on ironing device that lays down different kinds of custom ‘tapes’ on to textiles. The conductive fabric tapes can be used as touchable traces, and can support components such as flexible e-ink screens and solar panels. Some tapes provide single or multiple points of connectivity, and others are helper substrates like polyimide tape that multiply the possibilities for complex circuits.
The device uses a modified soldering iron to transfer the tapes, which are loaded onto 3D-printed spools that double as the wheels. Check it out after the break — there’s a 30-second tour and a 5-minute exploration of the whole process.
Do you need portable power that packs a punch? Sure you do, especially if you want to light up the night by mummifying yourself with a ton of LED strips. You aren’t limited to that, of course, but it’s what we pictured when we read about [Jeremy]’s Thunder Pack. With four PWM channels at 2.3 A each, why not go nuts? [Jeremy] has already proven the Thunder Pack out by putting it through its paces all week at Burning Man.
After a few iterations, [Jeremy] has landed on the STM32 microcontroller family and is currently working to upgrade to one with enough flash memory to run CircuitPython.
The original version was designed to run on a single 18650 cell, but [Jeremy] now has three boards that support similar but smaller rechargeable cells for projects that don’t need quite as much power.
Given that we are living in what most of humanity would now call “the future”, we really ought to start acting like it. We’re doing okay on the electric cars, but sartorially we’ve got some ground to make up. Helping with this effort is [Amy Goodchild], who put together a fancy LED shirt for all occasions.
The basis of the shirt is an ESP8266 running the FastLED library, hooked up to strings of WS2812B LEDs. It’s a great combination for doing quick and simple colorful animations without a lot of fuss. The LED strips are then fastened to the shirt by sewing them on, with heatshrink added to the strips to give the thread something to attach to. Tulle fabric is used as a diffuser, hiding the strips when they’re off and providing a more pleasant glowing effect. Everything is controlled from a small box, fitted with an arcade button and 7-segment display.
It’s a fun piece that’s readily achievable for the novice maker, and a great way to learn about LEDs and sewing. We’ve seen other similar builds before, such as this glowing LED skirt. Video after the break.
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.