Self-Glowing Ring Is Its Own Battery

LED jewelry has always been a popular part of the maker community. Oftentimes, coin cells are used as a compact source of power, or wires are run to discreet hidden battery packs. [OguzC3] went another route, however, creating a glowing ring which works as its own battery.

The design will be familiar to those who have done high-school experiments on basic batteries. An aluminium pipe forms the inner surface of the ring, which is then wrapped in a layer of newspaper. A copper outer ring is then placed outside. When soaked in a salt water solution, this forms a basic battery. The voltage output is only around 0.5 volts, so a joule thief circuit is built into the ring to step this up high enough to drive an LED. [OguzC3] reports that the ring lasts several hours at a time, and only needs a quick rinse in fresh salty water to recharge.

It’s a creative concept, and the final piece looks like a magical object from the world of fantasy. It would make a great addition to any cosplay, and we’re sure the technique could be adapted to other accoutrements, too. A similar experiment done in a more extreme way is this electric car charged via lemons. If you’ve got your own battery chemistry project cooking up at home, be sure to let us know!

Magic Acrylic Makes This Ring Stand Out

LEDs look great no matter how you use them, but sometimes you want to hide them from direct view. [Charlyn] found a great way to do that, using a special material designed just for the purpose.

[Charlyn] built a ring as a piece of fashion jewelry, hooking up a Gemma M0 microcontroller to a Neopixel Jewel, which packs 7 individual LEDs. The hardware is secreted away inside an enclosure featuring both 3D-printed and lasercut parts.

Rather than openly show off the electronics, it’s all hidden away inside. Instead, a piece of black Chemcast LED acrylic is used, which allows LED light to shine through, while otherwise appearing opaque. Those interested in learning more can check out the product details on the manufacturer site.

It’s a great way to make a subtle costume piece that only reveals its flashier side when you so decide. We’ve seen badges use similar techniques on PCBs to great effect, too. Video after the break.

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Hardware Hack Makes Robocall Blocking Service Even Better

Sorry to bear sad tidings, but your car’s extended warranty is about to expire. At least that’s what you’ll likely hear if you answer one of those robocalls that have descended like a plague upon us. We applaud any effort to control the flood of robocalls, even if it means supplementing a commercial blocking service with a DIY ring-blocker.

The commercial service that [Jim] engaged to do his landline blocking is called Nomorobo – get it? It uses the Simultaneous Ringing feature many VoIP carriers support to intercept blacklisted robocallers, but with a catch: it needs caller ID data, so it lets the first ring go through. [Jim]’s box intercepts the ringing signal coming from his Xfinity modem using a full-wave rectifier and an analog input on an Arduino. Once the ring pattern is received, the Arduino flips a relay that connects all the phones in the house to the line, letting the call ring through. If Nomorobo has blocked the call, he’ll never hear a thing. There were a few glitches to deal with, like false positives from going off- and on-hook, but those were handled in software. There’s also a delay in displaying caller ID information on his phones, but it’s a small price to pay for peace.

Any escalation in the war on robocalls is justified, and we applaud [Jim] for his service. Should you feel like joining the fray, step one is to know your enemy. This primer on robocalling will help.

Thanks to [Phil] for the tip.

Creating A Custom Engagement Ring With 3D-Printing

Even if you’re pretty sure what the answer will be, a marriage proposal is attended by a great deal of stress to make the event as memorable and romantic as possible. You’ve got a lot of details to look after, not least of which is the ring. So why not take some of the pressure off and just 3D-print the thing?

No, a cheesy PLA ring is probably not going to cut it with even the most understanding of fiancees, and that’s not at all what [Justin Lam] did with this DIY engagement ring. He took an engineer’s approach to the problem – gathering specs, making iterative design changes in Fusion 360, and having a prototype ring SLA printed by a friend. That allowed him to tweak the design before sending it off to Shapeways for production. We were surprised to learn that jewelry printing is a big deal, and Shapeways uses a lost-wax process for it. First a high-resolution wax SLA printer is used to make a detailed positive, which is then used to make a plaster mold. The mold is fired to melt the wax, and molten gold is poured in to make the rough casting, which is cleaned and polished before shipping.

Once he had the ring, [Justin] watched a few jewelry-making videos to learn how to set the family heirloom stone into the bezel setting; we admit we cringed a bit when he said he used the blade shaft of a screwdriver to crimp the edge of the bezel to the stone. But it came out great, even if it needed a bit of resizing. The details of the proposal are left to the romantically inclined, but TL;DR – she said yes.

Congratulations to the happy couple, and to [Justin] for pulling off a beautiful build. Most of our jewelry hacks are of the blinkenlight variety rather than fine jewelry, although we have featured a machinist’s take on the subject before.

An RFID Ring For The Body Mod Squeamish

Some people get inked, while others get henna or those water transfer tattoos you might find in a box of Cracker Jack. [Becky] wanted the benefits of having an RFID tag in her finger — unlock doors or log into your computer with a swipe of your finger — but wasn’t ready to get an implant. Her solution: make an artistic ring that conceals a tiny glass capsule RFID tag.

Besides not having to shove some tech under your epidermis, there are a few other advantages: you can change out tags as easy as changing rings, for one. You can also easily loan your ring to someone just as you might give them keys to your door.

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Analog Clock Goes Digital, Or Vice Versa

Designing a good clock takes a lot of considerations. It’s not just hands, faces, and numbers anymore; there are also word clocks, electronic clocks, marble clocks, or water clocks, and just about anything else imaginable can be used to tell time. Of course, electronic clocks are great for their versatility, and this one shows off an analog-looking clock that is (of course) digital, leveraging all of the perks of analog with all of the upsides of digital electronics.

One of the key design considerations that [Sasa] had while building this piece was that it needed to be silent. LEDs certainly fit that description, so the decision was made to go with an WS2812b ring. It runs using a STM ST32F103 Nucleo board (and a cheaper version of it in later versions of this clock) which shows a red LED for the current hour, yellow LEDs for the traditional analog clock divisions, a green LED for the current minute, and glows the rest of the LEDs up to the current minute with a rainbow pattern.

This is a really clean, simple build with good design at its core, and would be easy to replicate if you’re looking for an eye-catching clock to build. As a bonus, all of the schematics and code are available on the project site, so everything you need is there. If you’re looking for more inspiration, there are some clocks that are even more unique, like this marble clock that is a work of art — but is anything but silent.

Membership Ring Of The Electronic Illuminati

When the cabal of electronic design gurus that pull the invisible strings of the hardware world get together, we imagine they have to show this ring to prove their identity. This is the work of [Zach Fredin], and you’re going to be shocked by the construction and execution of what he calls Cyborg Ring.

The most obvious feature of the Cyborg Ring is the collection of addressable LEDs that occupy the area where gems would be found on a ring. What might not be so obvious is that this is constructed completely of electronic components, and doesn’t use any traditional mechanical parts like standoffs. Quite literally, the surface mount devices are structural in this ring.

They are also electrical. Here you can see a detail of how [Zach] pulled this off. We are looking at the underside of the ring, the part that goes below your knuckle. One of the two PCBs that are sized to fit your finger has been placed in a Stick Vise while the QFN processor is soldered on end, and the pairs of SMD resistors are put in place.

The precise measurements of each part make it possible to choose components that will perfectly span the gap between the two boards. In the background of the image you can see SMD resistors on their long ends — a technique he used to allow the LEDs themselves to span between one resistor on each of the two PDBs to complete the circuit. Incredible, right?

But it gets better. [Zach] ended up with a working prototype, but has continued to forge ahead with new design iterations. These updates are a delight to read! Make sure you follow his project and check in regularly; if you’ve already looked at this now’s the time to go back and see the new work. The gold pads for the minuscule coin cells which power the ring are being reselected as the batteries didn’t fit well on the original. Some layout problems are being tweaked. And the new spin of boards should be back from fab in a week or so.

Don’t miss the demo video found below. We really like seeing projects that build within the wearble ring form factor. It’s an impressive constraint which [Zach] seems to have mastered. Another favorite of ours is [Kevin’s] Arduboy ring.

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