Building A Piezo Noise Box

The humble piezo element is often used as little more than a buzzer in many projects. However, you can do more with them, as [Something Physical] demonstrates with their nifty piezo noise box. Check out the video (and audio) below.

The construction is simple enough, attractive in its own way, with a rugged junk-assembly sort of style. The video starts out by demonstrating the use of a piezo element hooked up as a simple contact microphone, before developing it into something more eclectic.

The basic concept: Mount the piezo element to a metal box fitted with a variety of oddball implements. What kind of implements? Spiralled copper wires, a spring, and parts of a whisk. When struck, plucked, or twanged, they conduct vibrations through the box, the microphone picks them up, and the box passes the sound on to other audio equipment.

It might seem frivolous, but it’s got some real value for avant-garde musical experimentation. In particular, if you’re looking for weird signals to feed into your effects rack or modular synth setup, this is a great place to start.

We’ve seen piezos put to other percussive uses before, too.

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Ancient SoundBlaster Cards Just Got A Driver Update

Old hardware tends to get less support as the years go by, from both manufacturers and the open-source community alike. And yet, every now and then, we hear about fresh attention for an ancient device. Consider the ancient SoundBlaster sound card that first hit the market 31 years ago. [Mark] noticed that a recent update squashed a new bug on an old piece of gear.

Jump over to the Linux kernel archive, and you’ll find a pull request for v6.16-rc3 from [Takashi Iwai]. The update featured fixes for a number of sound devices, but one stands out amongst the rest. It’s the SoundBlaster AWE32 ISA sound card, with [Iwai] noting “we still got a bug report after 25 years.” The bug in question appears to have been reported in 2023 by a user running Fedora 39 on a 120 MHz Pentium-based machine.

The fixes themselves are not particularly interesting. They merely concern minutiae about the DMA modes used with the old hardware. The new updates ensure that DMA modes cannot be changed while the AWE32 is playing a PCM audio stream, and that DMA setups are disabled when changing modes. This helps avoid system lockups and/or ugly noises emanating from the output of the soundcard.

It’s incredibly unlikely this update will affect you, unless you’re one of a handful of users still using an ISA soundcard in 2025. Still, if you are — and good on you — you’ll be pleased someone still cares about your user experience. Meanwhile, if you’re aware of any other obscure old-school driver updates going on out there, don’t hesitate to let us know on the tips line. Want to relive your ISA card’s glory days? Plug it into USB.

Image credit: Gona.eu, CC BY-SA 3.0

[Thanks to Meek Mark for the tip!]

BeyBlades Made Ever More Dangerous With 3D Printing

If you’re unfamiliar with Beyblades, they’re a simple toy. They consist of spinning tops, which are designed to “fight” in arenas by knocking each other around. While the off-the-shelf models are deemed safe enough for children to play with, [Jon Bringus] decided to take the danger level up a few notches with some custom launchers of his own design.

[Jon]’s project started with some of the early metal Beyblades, which are traditionally launched with a small geared ripcord device. He soon realized he could up the action by doing one simple thing—spinning the tops far faster than the manufacturer ever intended. More rotational speed equals more kinetic energy equals more legal liability fun, or so the equation goes.

The design for [Jon’s] “WMD Launcher” is straightforward enough—he combined a lawnmower pull starter with a 12:1 geartrain to turn the Beyblades at truly ludicrous speeds. It’s basic engineering — a couple of 3D-printed gears do the job — but the results are hilarious. The tops begin to emit loud noises as they turn in combat, and some move so fast and erratically that they won’t even stay inside the arena. Protective eyewear is virtually mandatory. Files are on Printables for those eager to build one at home.

Yes, ruining a game of Beyblades is as simple as building an irresponsibly fast launcher. You needn’t even use some fancy brushless motor to hurt yourself — just a little gearing is enough to cause havoc. We’ve featured similar work on this topic before, too. Video after the break.

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Building A 3D-Printed RC Dump Truck

Whatever your day job, many of us would love to jump behind the controls of a dump truck for a lark. In the real world, that takes training and expertise and the opportunity is denied to many of us. However, you can live out those dreams on your desk with this 3D-printed build from [ProfessorBoots.]

The build exists as two separate parts—the tractor, and the trailer. The tractor is effectively a fairly straightforward custom RC build, albeit with a few additional features to make it fit for purpose. It’s got six wheels as befitting a proper semi, and it has a nifty retractable magnetic hitch mechanism. This lets it hook up to various trailers and unhitch from them as desired, all from a press on the remote. The hitch also has provision for power and control lines that control whatever trailer happens to be attached.

As for the trailer, it’s a side-dumper that can drop its load to the left or right as desired. The dumping is controlled via a linear actuator using a small DC motor and a threaded rod. A servo controls a sliding locking mechanism which determines whether the truck dumps to the left or right as the linear actuator rises up.

The design video covers the 3D printed design as well as some great action shots of the dump truck doing its thing. We’ve featured some builds from [ProfessorBoots] before, too, like this neat 3D-printed forklift . Video after the break.

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Standing Desk Uses Pneumatics To Do The Job

Most standing desks on the market use electric motors or hand cranks to raise and lower the deck. However, [Matthias Wandel] found a Kloud standing desk that used an altogether different set up. He set about figuring out how it worked in the old-fashioned way—by pulling it apart.

The Kloud desk relies on pneumatics rather than electrical actuators to move up and down. Inside the desk sits a small tank that can be pressurized with a hand-cranked mechanism. A lever can then be used to release pressure from this tank into a pair of pneumatic cylinders that drive the top of the desk upwards. The two cylinders are kept moving in sync by a tensioned metal ribbon that ties the two sides together. The mechanism is not unlike a gas lift chair—holding the lever and pushing down lets the desk move back down. Once he’s explained the basic mechanism, [Matthias] gets into the good stuff—pulling apart the leg actuator mechanism to show us what’s going on inside in greater detail.

If you’ve ever thought about building your own standing desk, this might be a video worth watching. We’ve featured some other great pneumatics projects before, too. Video after the break.

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Can Digital Poison Corrupt The Algorithm?

These days, so much of what we see online is delivered by social media algorithms. The operations of these algorithms are opaque to us; commentators forever speculate as to whether they just show us what they think we want to see, or whether they try to guide our thinking and habits in a given direction. The Digital Poison device  from [Lucretia], [Auxence] and [Ramon] aims to twist and bend the algorithm to other ends.

The concept is simple enough. The device consists of a Raspberry Pi 5 operating on a Wi-Fi network. The Pi is set up with scripts to endlessly play one or more select YouTube videos on a loop. The videos aren’t to be watched by anyone; the device merely streams them to rack up play counts and send data to YouTube’s recommendation algorithm. The idea is that as the device plays certain videos, it will skew what YouTube recommends to users sharing the same WiFi network based on perceived viewer behavior.

To achieve subtle influence, the device is built inside an unobtrusive container. The idea being that it could be quietly connected to a given WiFi network to stream endlessly, in turn subtly influencing the view habits of other users on the same network.

It’s difficult to say how well this concept would work in practice. In many cases, sites like YouTube have robust user tracking that feeds into recommendation algorithms. Activity from a random user signed into the same network might not have much of an influence. However, conceptually, it’s quite interesting, and the developers have investigated ways to log the devices operation and compare it to recommendations fed to users on the network. Privacy provisions make this difficult, but it may be possible to pursue further research in this area. Files are on Github for the curious.

Ultimately, algorithms will always be a controversial thing as long as the public can’t see how they work or what they do. If you’re working on any projects of your own in this space, don’t hesitate to let us know!

[Thanks to Asher for the tip!]

Audio Localization Gear Built On The Cheap

Most humans with two ears have a pretty good sense of directional hearing. However, you can build equipment to localize audio sources, too. That’s precisely what [Sam], [Ezra], and [Ari] did for their final project for the ECE4760 class at Cornell this past Spring. It’s an audio localizer!

The project is a real-time audio localizer built on a Raspberry Pi Pico. The Pico is hooked up to three MEMS microphones which are continuously sampled at a rate of 50 kHz thanks to the Pico’s nifty DMA features. Data from each microphone is streamed into a rolling buffer, with peaks triggering the software on the Pico to run correlations between channels to determine the time differences between the signal hitting each microphone. Based on this, it’s possible to estimate the location of the sound source relative to the three microphones.

The team goes into great deal on the project’s development, and does a grand job of explaining the mathematics and digital signal processing involved in this feat. Particularly nice is the heatmap output from the device which gives a clear visual indication of how the sound is being localized with the three microphones.

We’ve seen similar work before, too, like this project built to track down fireworks launches. Video after the break.

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