Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With John Lennon’s Typewriter

April 15, 2025 by 2 Comments

The Clawtype, a one-handed number with a handy strap and a good-sized display.
Image by [akavel] via GitHub
Reader [akavel] was kind enough to notify me about Clawtype, which is a custom wearable chorded keyboard/mouse combo based on the Chordite by [John W. McKown].

First of all, I love the brass rails — they give it that lovely circuit sculpture vibe. This bad boy was written in Rust and currently runs on a SparkFun ProMicro RP2040 board. For the mouse portion of the program, there’s an MPU6050 gyro/accelerometer.

[akavel]’s intent was to pair it with XR glasses, which sounds like a great combination to me. While typing is still a bit slow, [akavel] is improving at a noticeable pace and does some vim coding during hobby time.

In the future, [akavel] plans to try a BLE version, maybe even running off a single AA Ni-MH cell, and probably using an nRF52840. As for the 3D-printed shape, that was designed and printed by [akavel]’s dear friend [Cunfusu], who has made the files available over at Printables. Be sure to check it out in the brief demo video after the break.

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Shine On You Crazy Diamond Quantum Magnetic Sensor

April 15, 2025 by 21 Comments

We’re probably all familiar with the Hall Effect, at least to the extent that it can be used to make solid-state sensors for magnetic fields. It’s a cool bit of applied physics, but there are other ways to sense magnetic fields, including leveraging the weird world of quantum physics with this diamond, laser, and microwave open-source sensor.

Having never heard of quantum sensors before, we took the plunge and read up on the topic using some of the material provided by [Mark C] and his colleagues at Quantum Village. The gist of it seems to be that certain lab-grown diamonds can be manufactured with impurities such as nitrogen, which disrupt the normally very orderly lattice of carbon atoms and create a “nitrogen vacancy,” small pockets within the diamond with extra electrons. Shining a green laser on N-V diamonds can stimulate those electrons to jump up to higher energy states, releasing red light when they return to the ground state. Turning this into a sensor involves sweeping the N-V diamond with microwave energy in the presence of a magnetic field, which modifies which spin states of the electrons and hence how much red light is emitted.

Building a practical version of this quantum sensor isn’t as difficult as it sounds. The trickiest part seems to be building the diamond assembly, which has the N-V diamond — about the size of a grain of sand and actually not that expensive — potted in clear epoxy along with a loop of copper wire for the microwave antenna, a photodiode, and a small fleck of red filter material. The electronics primarily consist of an ADF4531 phase-locked loop RF signal generator and a 40-dB RF amplifier to generate the microwave signals, a green laser diode module, and an ESP32 dev board.

All the design files and firmware have been open-sourced, and everything about the build seems quite approachable. The write-up emphasizes Quantum Village’s desire to make this quantum technology’s “Apple II moment,” which we heartily endorse. We’ve seen N-V sensors detailed before, but this project might make it easier to play with quantum physics at home.

GLaDOS Potato Assistant

This Potato Virtual Assistant Is Fully Baked

April 15, 2025 by 10 Comments

There are a number of reasons you might want to build your own smart speaker virtual assistant. Usually, getting your weather forecast from a snarky, malicious AI potato isn’t one of them, unless you’re a huge Portal fan like [Binh Pham].

[Binh Pham] built the potato incarnation of GLaDOS from the Portal 2 video game with the help of a ReSpeaker Light kit, an ESP32-based board designed for speech recognition and voice control, and as an interface for home assistant running on a Raspberry Pi.

He resisted the temptation to use a real potato as an enclosure and wisely opted instead to print one from a 3D file he found on Thingiverse of the original GLaDOS potato. Providing the assistant with the iconic synthetic voice of GLaDOS was a matter of repackaging an existing voice model for use with Home Assistant.

Of course all of this attention to detail would be for naught if you had to refer to the assistant as “Google” or “Alexa” to get its attention. A bit of custom modelling and on-device wake word detection, and the cyborg tuber was ready to switch lights on and off with it’s signature sinister wit.

We’ve seen a number of projects that brought Portal objects to life for fans of the franchise to enjoy, even an assistant based on another version of the GLaDOS the character. This one adds a dimension of absurdity to the collection.

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Building A DIY Tornado Tower

April 14, 2025 by 13 Comments

A tornado can be an awe-inspiring sight, but it can also flip your car, trash your house, and otherwise injure you with flying debris. If you’d like to look at swirling air currents in a safer context, you might appreciate this tornado tower build from [Gary Boyd].

[Gary]’s build was inspired by museum demonstrations and the tornado machine designs of [Harald Edens]. His build generates a vortex that spans 1 meter tall in a semi-open cylindrical chamber. A fan in the top of the device sucks in air from the chamber, and exhausts it through a vertical column of holes in the wall of the cylinder. This creates a vortex in the air, though it’s not something you can see on its own. To visualize the flow, the cylindrical chamber is also fitted with an ultrasonic mist generator in the base. The vortex in the chamber is able to pick up this mist, and it can be seen swirling upwards as it is sucked towards the fan at the top.

It’s a nice educational build, and one that’s as nice to look at as it is to study. It produces a thick white vortex that we’re sure someone could turn into an admirable lamp or clock or something, this being Hackaday, after all. In any case, vortexes are well worth your study. If you’re cooking up neat projects with this physical principle, you should absolutely let us know!

Plasmonic Modulators Directly Convert Terahertz Waves To Optical Signals

April 14, 2025 by 5 Comments

A major bottleneck with high-frequency wireless communications is the conversion from radio frequencies to optical signals and vice versa. This is performed by an electro-optic modulator (EOM), which generally are limited to GHz-level signals. To reach THz speeds, a new approach was needed, which researchers at ETH Zurich in Switzerland claim to have found in the form of a plasmonic phase modulator.

Although sounding like something from a Star Trek episode, plasmonics is a very real field, which involves the interaction between optical frequencies along metal-dielectric interfaces. The original 2015 paper by [Yannick Salamin] et al. as published in Nano Letters provides the foundations of the achievement, with the recent paper in Optica by [Yannik Horst] et al. covering the THz plasmonic EOM demonstration.

The demonstrated prototype can achieve 1.14 THz, though signal degradation begins to occur around 1 THz. This is achieved by using plasmons (quanta of electron oscillators) generated on the gold surface, who affect the optical beam as it passes small slots in the gold surface that contain a nonlinear organic electro optic material that ‘writes’ the original wireless signal onto the optical beam.

A man is looking at a volumetric display while using one finger to interact with it. Two roughly-spherical blue shapes are visible in the display, and he is moving his index finger toward one of them.

Elastic Bands Enable Touchable Volumetric Display

April 14, 2025 by 12 Comments

Amazing as volumetric displays are, they have one major drawback: interacting with them is complicated. A 3D mouse is nice, but unless you’ve done a lot of CAD work, it’s a bit unintuitive. Researchers from the Public University of Navarra, however, have developed a touchable volumetric display, bringing touchscreen-like interactions to the third dimension (preprint paper).

At the core, this is a swept-volume volumetric display: a light-diffusing screen oscillates along one axis, while from below a projector displays cross-sections of the scene in synchrony with the position of the screen. These researchers replaced the normal screen with six strips of elastic material. The finger of someone touching the display deforms one or more of the strips, allowing the touch to be detected, while also not damaging the display.

The actual hardware is surprisingly hacker-friendly: for the screen material, the researchers settled on elastic bands intended for clothing, and two modified subwoofers drove the screen’s oscillation. Indeed, some aspects of the design actually cite this Hackaday article. While the citation misattributes the design, we’re glad to see a hacker inspiring professional research.) The most exotic component is a very high-speed projector (on the order of 3,000 fps), but the previously-cited project deals with this by hacking a DLP projector, as does another project (also cited in this paper as source 24) which we’ve covered.

While interacting with the display does introduce some optical distortions, we think the video below speaks for itself. If you’re interested in other volumetric displays, check out this project, which displays images with a levitating styrofoam bead.

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ESP32-Powered Clock Brings Aviation Style To Your Desk

April 14, 2025 by 14 Comments

There’s something cool about the visual design language used in the aviation world. You probably don’t get much exposure to it if you’re not regularly flying a plane, but there are other ways you can bring it into your life. A great example would be building an aviation-themed clock, like this stylish timepiece from [oliverb.]

The electronic heart of the build is an ESP32. This wireless-capable microcontroller is a popular choice for clock builds these days. This is because it can contact network time servers out of the box, which allows you to build an incredibly capable and accurate clock without any additional parts. No real-time-clock needed—just have the ESP32 buzz the Internet for an accurate update on the regular!

As for the display itself, three gauges show hours, minutes, and seconds on aviation-like gauges. They’re 3D-printed, which means you can build them from scratch. That’s a touch easier than having to go out and source actual surplus aviation hardware. Each gauge is driven by a NEMA17 stepper motor. There’s also an ATMEGA328 on hand to drive a 7-segment gauge on the seconds display, and a PIR sensor which shuts the clock down when nobody is around to view it.

It’s a tidy build, and one with a compelling aesthetic at that. We’ve seen some similar builds before using real aviation gauges, too. Video after the break.

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