Custom AMOLED Wearable Makes Great Icebreaker

September 10, 2026 by No comments

Nifty little AMOLED screens are easy to get nowadays, and [Sophie D] demonstrates they are both thin and light enough to be worn with OpenChoker, a design for a choker necklace that was a hit at DEF CON.

The choker consists of an AMOLED touchscreen flanked by short RGB LED strips. Behind the display is the PCB which contains an RP2350 and micro SD card slot for external storage, and at the rear of the choker is an 18650 cell to power it all. The display plays an eye-catching animation that gets generated on the fly while the LEDs sparkle away.

[Sophie] shares a number of interesting takeaways from designing and building this device. One is that the bulk of the PCB design work was interfacing to the display, since no existing footprint or reference design could be found. So if you find yourself with a Hello Lighting HL020E21-02 2.14″ touchscreen display you’re hankering to use in your own project, do yourself a favor and check out [Sophie]’s board design instead of starting from scratch.

Battery life was more than enough for a device like this. A single 18650 cell powered the choker effortlessly for a 16-hour stretch and still the cell measured a robust 3.7 V. While a light-up choker used indoors isn’t a great candidate for wearable solar power, it’s encouraging that there’s no need for a tethered battery pack.

Another tip to consider relates to the screen’s touch sensitivity. In short, the capacitive touch screen responded perfectly when plugged into a development computer, but when mounted and isolated on the choker it responded so poorly as to be useless. It didn’t keep the rest of the choker from doing its job, but it might be worth keeping in mind as something to watch out for with a device like this.

There’s one final mystery [Sophie] ran into: with only one day to spare, glue used to affix some wires ended up melting away the wire insulation, revealing bare copper. We’re not sure what happened there, but if nothing else it’s a reminder that Murphy’s Law is always ready to strike when one is on a deadline.

Tech In Plain Sight: Meet The Robot That Does CPR

September 10, 2026 by 2 Comments

Usually in Tech In Plain Sight, we talk about technology you probably see every day, even if you don’t notice it. But we hope you don’t get to see one of the latest crop of medical robots, such as the LUCAS chest compression system. If you watch the popular TV series “The Pitt”, though, you may have caught a glimpse of one of these medical marvels. They aren’t fiction. They are very real devices.

Calling them robots might be stretching the definition a little. They don’t roam the halls looking for patients. But once attached to someone in cardiac arrest, they can take over one of the most important — and physically demanding — parts of CPR: chest compressions.

Keep The Blood Moving

When someone’s heart stops pumping blood, time is critical. CPR doesn’t normally restart the heart on its own. Instead, chest compressions produce enough blood flow to keep oxygen reaching the brain and heart while rescuers work on the underlying problem and, when appropriate, use a defibrillator.

Doing that well is harder than it looks on television. Current American Heart Association guidelines call for adult chest compressions 100 to 120 times per minute, at least 5 cm deep but generally no deeper than 6 cm, while allowing the chest to recoil fully between compressions. Interruptions should be kept to a minimum.

That’s hard physical work. In fact, studies show compression depth begins to fall after only about 90 to 120 seconds, which is one reason CPR teams normally swap compressors every two minutes. But a robot doesn’t get tired.

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Open Source Acoustic Drone Detection

September 10, 2026 by 8 Comments

Drones have become a potent military threat, particularly on the small scale. Nimble multi-rotor drones are fast, difficult to spot, and can cause plenty of harm if allowed to go about their work unhindered. The first step to dealing with this issue is detection—a problem that [Agam Rossen] has put some work into.

The result is VolAnti—an open-source drone detector. This route was chosen as a reliable way to detect incoming multi-rotors, since spinning propellers tend to create a telltale sound that can be plucked from the noise quite specifically. In a world where fiber optic drones eschew RF emissions, it also proves particularly useful for early warning of such craft.

VolAnti relies on a small four-microphone array, with the I2S output of all four mics summed together. The output is then fed into a 2048-point FFT running every 32 ms on an ESP32-S3. A comb score is given to try and pick out different blade rates from 70 Hz to 2000 Hz. Multiple detection algorithms run in parallel, because [Agam] noted a problem—using an adaptive noise floor would miss drones that arrived in the area and hovered in place. With the noise not varying, it would get filtered out by the adaptive floor, so one algorithm in the four runs with no floor to catch drones that aren’t moving. Files are on GitHub for those curious to learn more.

We’ve featured other acoustic detection projects before, too. If you’re working on something similar, or conversely, you have the inside scoop on how to hide a drone’s noise signature, don’t hesitate to let us know on the tipsline.

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If It’s Electronic Paper, Why Not Print To It?

September 10, 2026 by 10 Comments

E-ink is supposed to be the electronic version of dead-tree paper, but there’s one enormous difference: how you get your images and text onto it. For paper, you print on it. E-ink? Well, it depends on what it’s hooked up to. If it’s an ESP32C3-based Xteink X4 and X3, then you can just print to that, too, thanks to [Nishant Joshi]’s fork of the popular CrossPoint firmware.

The fork implements the Internet Printer Protocol, IPP, on the ESP32-C3. It makes loading documents a breeze: select the printer in your operating system, and press print. To the computer, the reader advertises itself as a printer that provides monochrome, single-sided output at 300 DPI on A5 paper, and accepts Apple raster and PWG raster formats. Of course these raster images are enormous compared to the paltry RAM available on the microcontroller, so pixels are received and written row-by-row — both to the screen directly, and to the SD card for later perusal. That makes a folder on the SD card the equivalent of a printer’s output tray.

This interface is amazing in its simplicity, and we’d love to see it in other E-ink devices. It reminds us somehow of AlphaSmart word processors — which are still relevant today in large part because their ‘file transfer’ mechanism is to pretend to be a USB keyboard and type the document onto your computer. As long as IPP is available, so too will you be able to get documents onto this e-reader.

Origami Sensors That You Can Wear

September 9, 2026 by No comments

Origami is a wonderful art form, but as a new project from the Shibaura Institute of Technology demonstrates, it can also have applications in the world of wearable tech.

The project involved creating paper-based sensors that could be worn on the body. These sensors were designed to be self-folding into helical forms, which would allow them to adapt neatly to the wearer over a wide range of body dimensions. This was achieved by using a standard inkjet printer to print patterns onto a flat piece of paper, with the printed patterns creating a self-folding behavior in the paper itself. Copper tape was then applied to the paper in order to act as an electrode for picking up triboelectric signals and measuring galvanic skin response. The idea is that these methods could be used to quickly and easily produce custom low-cost wearable sensors for a range of applications.

We’ve featured all kinds of interesting wearable hacks over the years, from power delivery via skin to shirts that will hide you from automated surveillance system. If you’re working on your own fancy projects that hang, clip, or dangle from the human body, don’t hesitate to let us know on the tipsline.

3D Printable Lenticular Indicators

September 9, 2026 by 13 Comments

You can 3D print all kinds of things, from Yoda heads to little models of Pikachu. Eventually, though, most of us get to a point where we want to print something a little more interesting. The lenticular prints developed by MIT CSAIL are very much that. (h/t Core77).

The ShiftLens concept is simple enough—there’s a lens layer printed in transparent material. Beneath that, lives a patterned layer in alternating colors, corresponding with the linear lenses of the layer above. Then, there’s an actuation mechanism that can shift the lens layer relative to the pattern layer. This creates a changing color effect as the mechanism is shifted. The actuation mechanism can be a knob, switch, or roller—anything that moves the layers relative to each other. On its own, it’s a bit of a curio—but there are some fun demos. In particular, using the lenticular printing on a bottle to form an indicator for when the container is closed properly. There isn’t a publicly available design tool for these prints yet, though the team developed one for Rhino that they used internally for the project.

It’s a pretty interesting application of 3D printing, and one that we fully expect a bunch of YouTubers to replicate within the month. We’ve featured some other great print hacks lately, too, like a slicer that lets you print horizontal overhangs without support. Video after the break.

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Local LLMs Can Work Better Than Claude, At Least For Some

September 9, 2026 by 34 Comments

This is going to be a very personal question, because when you’re talking cloud vs local anything, it comes down to this: how much are you willing to pay for independence? The local option might save you long term, or it might never pay off the capital investment. It will almost certainly cost you your time to set up and maintain your own system — but what you get back is independence. With LLMs, traditionally you lose quite a bit of performance, but as [Anurag Singh] points out on XDA Developers, a lesser model might actually let you get more done, depending on your workflow.

[Anurag] had been on the 20$/month plan with Anthropic when he decided that the scratch just wasn’t worth the sniff– he was hitting usage limits he couldn’t stand at that level, but couldn’t justify a higher tier of access. So he decided to try a local LLM, even though all he had was a 16 GB MacBook Air M5, not a beefy workstation. Since his workflow isn’t so much ‘vibe code the whole thing for me’ as ‘help me find where I went wrong here, electronic rubber duck’, Qwen2.5 Coder 14B proved more than adequate for his use case.

It can’t understand all the moving parts of a large project as well as Claude can — not surprising given how old it is and how much memory it has to work with — but that’s [Anurag]’s job. He’s the programmer, it’s just the assistant. For his use case, he can make use of his existing hardware and having the the LLM right in VS Code is allows for a speedy workflow.

Your millage may vary, but if you want to get into locally running LLMs, we can point you at the easy ways to get started. Depending on your hardware, you might want to grab another GPU.