Kritik sah

There are a ton of inventions out in the world that are almost complete accidents, but are still ubiquitous in our day-to-day lives. Things like bubble wrap which was originally intended to be wallpaper, or even superglue, a plastic compound whose sticky properties were only discovered later on. IBM found themselves in a similar predicament in the 1970s after working on a type of mainframe computer made to be a phone switch. Eventually the phone switch was abandoned in favor of a general-purpose processor but not before they stumbled onto the RISC processor which eventually became the IBM 801 . As [Paul] explains, the major design philosophy at the time was to use a large amount of instructions to do specific tasks within the processor. When designing the special-purpose phone switch processor, IBM removed many of these instructions and then, after the project was cancelled, performed some testing on the incomplete platform to see how it performed as a general-purpose computer. They

The conductor of an orchestra may look unassuming on the street, but once they step onto their podium, they are all powerful. If you’ve ever wanted to go mad with power in the comfort of your own home, try this electronic orchestra baton by [Larry Lu] and [Kathryn Zhang]. The wireless baton “peripheral” part of the system uses a Pico W and an IMU to detect the speed of conducting a 4/4 measure. That information is then transmitted to the “central” Pico W access point which plays a .wav at the speed corresponding to the conductor’s specified beats per minute (BPM). Setting the baton down will pause the visualizer and audio playback. The “central” Pico W uses direct memory access (DMA) and SPI communication to control the audio output and VGA visualization. Since most .wav files have a sample rate of 44.1 kHz, this gave the students a reference to increase or decrease the DMA audio channel timer to control the playback. Want some more musical hacks? Checkout this auto-glockenspiel

A triboelectric nanogenerator (TENG) certainly sounds like the sort of thing you’d need to graduate from Starfleet Engineering to put together, but it actually operates on the same principle that’s at work when you rub a balloon your head. Put simply, when friction is applied to the proper materials, charges can build up enough to produce a short burst of electrical energy. Do it enough, and you’re on the way to producing useful power. In a recent paper, [Leo N.Y. Cao], [Erming Su], [Zijie Xu], and [Zhong Lin Wang] describe how a functional TENG can be produced on a standard desktop 3D printer . What’s even more impressive is that the method doesn’t appear to require anything terribly exotic — just some commercially available filaments and a bunch of PTFE beads. TENGs can be printed in any size or shape. So how do your print your own TENG? First, you load up an electrically conductive PLA filament and lay down a base into which a series of channels has been designed. At around t

Sometimes you come across one of those ideas that at first appear to have to be some kind of elaborate joke, but as you dig deeper into it, it begins to make a disturbing kind of sense. This is where the idea of diagonally-oriented displays comes to the fore. Although not a feature that is generally supported by operating systems, [xssfox] used the xrandr (x resize and rotate) function in the Xorg display server to find the perfect diagonal display orientation to reach a happy balance between the pros and cons of horizontal and vertical display orientations. As displays have gone wide-and-wider over the past decades, some people rotate their displays 90 degrees to get more height instead, which is beneficial when reading documents, yet terrible when watching most video content, barring vertical videos, so you either need more than one display, keep rotating, or settle on an optimal intermediate compromise. Interestingly, this wasn’t found at a straight 45°, but instead at 22° of ro

If you have multiple microphones in known locations, and can determine the time a sound arrives at each one, you can actually determine the location that sound is coming from. This technique is referred to as sound localization via time difference of arrival. [Kim Hendrikse] decided to put the technique to good use to track down the location of illicit fireworks launches. The build is based on the Raspberry Pi, with [Kim] developing an “autonomous recording unit” complete with GPS module for determining their location and keeping everything time synchronized. By deploying a number of these units, spread out over some distance, it’s possible to localize loud sounds based on the time stamps they show up in the recording on each unit. Early testing took place with an air horn and four recording units. [Kim] found that the technique works best for sounds made within the polygon.  Determining the location was achieved with a sound investigation tool called Raven Lite , developed by Corn

[Thomas Roth], aka [Ghidraninja], and author of the [Stacksmashing] YouTube channel, investigated Apple’s Lightning port and created a cool debugging tool that allowed one to get JTAG on the device. Then, Apple went to USB-C for their new phones, and all his work went to waste. Oh well, start again — and take a look at USB-C . Turns out, though, that the iPhone 15 uses the vendor-defined messages (VDM) capability of USB-PD to get all sorts of fun features out. Others had explored the VDM capabilities on Mac notebooks, and it turns out that the VDM messages on the phone are the same. Some more fiddling, and he got a serial port and JTAG up and running. But JTAG is locked down in the production devices, so that will have to wait for an iPhone 15 jailbreak. So he went poking around elsewhere. He found some other funny signals that turned out to be System Power Management Interface (SPMI), one of the horribly closed and NDA-documented dialects owned by the MIPI Alliance. Digging around

Not every talk at the Chaos Communication Congress is about hacking computers. In this outstanding and educational talk, [Michael Büker] walks us through the history of our understanding of the planets . The question “What is a planet?” is probably more about the astronomers doing the looking than the celestial bodies that they’re looking for. In the earliest days, the Sun and the Moon were counted in. They got kicked out soon, but then when we started being able to see asteroids, Ceres, Vesta, and Juno made the list. But by counting all the asteroids, the number got up above 1,200, and it got all too crazy. Viewed in this longer context, the previously modern idea of having nine planets, which came about in the 1960s and lasted only until 2006, was a blip on the screen. And if you are still a Pluto-is-a-planet holdout, like we were, [Michael]’s argument that counting all the Trans-Neptunian Objects would lead to madness is pretty convincing. It sure would make it harder to build an

[Jason Winfield] shared with us a video describing a project with a lot of personality: a mounted, lit, and quivering Alien facehugger triggered by motion . The end result is a delightful jump scare, and the Raspberry Pi that controls everything also captures people’s reactions. It starts with a little twitch when motion is sensed, then launches into a perfectly unsettling quiver combined with light and sound. We particularly like the wave-like effect from the LED lighting, which calls to mind illumination from rotating hazard beacons. The unit looks like a mounted and tastefully-lit static model, but is actually primed to sense motion. One challenge was how to efficiently move the legs. Rather than use a motor for each limb, [Jason] settled on a single motor driving a rotating cam arrangement. You can see the results for yourself in the video below, but getting there was not simple. The surplus motor [Jason] chose is thin and high-torque, but runs extremely fast. Since he want

Students [Berk Gokmen] and [Justin Green] developed an RP2040-based LED-illuminated lightsaber as a final project with a bit of a twist . It has two unusual sound-reactive modes: disco mode, and vowel detection mode. Switching allegiances (or saber color, at least) is only a sound away. Disco mode alters the color of the saber dynamically in response to incoming sounds. Color and brightness are altered in response to incoming frequencies picked up by the on-board microphone, making a dynamic light show that responds particularly well to music. The second mode is vowel detection, and changes the lightsaber’s color depending on spoken sounds. The “ee” sound makes the saber red, and the “ah” sound turns it blue. This method requires a lot of processing and filtering, and in the end it works, but is quite dependent on individual speakers for calibration. The sound functionality centers around FFTs (Fast Fourier Transforms) which are fundamental to processing signals like audio in a

It was recently announced that US Steel will be acquired by Tokyo-based Nippon Steel for a measly $14.1 billion , ending the former’s 122 year history as a former US industrial powerhouse. Yet what happened to degrade what was once the number one steel maker in the world upon its formation out of two existing industrial giants in 1901 into a has-been? This is the topic that [Brian Potter] dives into in a recent article . Most of the how and why can be condensed into a simple reluctance to follow industry innovations, often passing on new technologies. This went well until the post-WWII era, when foreign competition began to heat up, with this competition more than happy to embrace whatever new steel making technologies became available. Case in point was the replacement of open hearth furnaces with basic oxygen furnaces by the early 1950s, which US Steel only began to adopt in the 1960s. These were then themselves largely replaced by contemporary electric arc furnaces, in a constant

There are many ways to lock a door. You could use a keypad, an RFID card, a fingerprint or retina scan, Wi-Fi, Bluetooth, the list goes on. You could even use a regular old metal key. But none of these may be as secure as [mircemk]’s Arduino-based door lock that employs a smartphone’s flashlight as a pass code. At first blush, this seems horribly insecure. Use a plain old flashlight to open a door? Come on. But the key is in the software. In fact, between the typed-in pass code and the flash of light it generates, this lock kind of has two layers of security. Here’s what’s going on: inside the accompanying smart phone application, there’s a list of passwords. Each of these passwords corresponds to a flash of light in milliseconds. Enter the correct password to satisfy the Arduino, and the phone’s flashlight is activated for the appropriate number of milliseconds to unlock the door. As you’ll see in the video below, simply flashing the light manually doesn’t unlock the door, and nei

Among users of Linux distributions there’s a curious one-upmanship, depending on how esoteric or hardcore  your distro is. Ubuntu users have little shame, while at the other end if you followed Linux From Scratch or better still hand-compiled the code and carved it onto the raw silicon with a tiny chisel, you’re at the top of the tree*. Jokes aside though, it’s fair to say that if you were running the Gentoo distribution you were something of a hardcore user, because its source-only nature meant that everything had to be compiled to your liking. We’re using the past tense here though, because in a surprise announcement, the distro has revealed that it will henceforth also be available as a set of precompiled binary packages . There may be readers with long and flowing neckbeards who will decry this moment as the Beginning of the End, but while it does signal a major departure for the distro if it means that more people are spurred to take their Linux usage further and experiment with

Microscopy of PMMA ferromagnetic Janus particle as used in the study (Credit: Wilson-Whitford et al., 2023) Granular media such as sand have a range of interesting properties that make it extremely useful, but they still will obey gravity and make their way downhill. That is, until you coat such particles with a ferromagnetic material like iron, make them spin using an external magnetic field and watch them make their way against gravity. This recent study by researchers has an accompanying video (also embedded below) that is probably best watched first before reading the study by Samuel R. Wilson-Whitford and colleagues in Nature Communications . In the supplemental material the experimental setup is shown (see top image), which is designed to make the individual iron-coated polymer particles rotate. The particles are called Janus particles because only one hemisphere is coated using physical vapor deposition, leaving the other as uncovered PMMA (polymethyl methacrylate). Whi

Inside shot of the Modvion wooden wind turbine tower. Modern-day wind turbines are constructed using mostly concrete and steel, topped by the fiberglass composite blades mounted to the nacelle that houses the gearbox and generator, along with much of the control systems. With the ever increasing sizes of these turbines transporting the components to the installation location is a harrowing task, something which Swedish company Modvion claims to improve upon with its wooden tower elements that come mostly packaged flat, for on-site assembly. The BBC recently took a look at the first of these partially wooden wind turbine towers. At 105 meters tall, it features a standard V90-2.0MW turbine and blades. Rather than using concrete slabs at the base with steel tower segments on top, or a fully steel tower like with most wind turbines, Modvion uses segments of layered wood which it calls ‘ the module ‘. These are assembled out of 144 layers of 3 mm thick spruce, with ring segments asse

We would all like to 3D print in metal, but for now, the equipment to do that is out of reach for most of us. Instead of dealing with powder printers or metal-bearing polymers, [Robert] has a simple solution. Using a process known as mechanical plating or peen plating, he deposits a layer of copper on a PLA print . The results look good, as you can see in the video below. This isn’t electroplating, although the result is similar. With electroplating, you have to make the 3D part conductive. You also have to deal with wet chemistry and fumes. This process uses a rock tumbler, copper powder, and small ball bearings. The ball bearings hammer the copper into the part, cold welding it to the surface. [Robert’s] first attempt didn´t work well as the copper didn’t stick well. He solved that by dipping the part in acetone. The video says that made the part sticky, but we haven’t found that to be true with PLA. We suspect it served to clean the part, an essential step in mechanical plating.

The Raspberry Pi is a popular choice if you’re looking to put together a simple emulation box — it’s relatively cheap, small enough to tuck into pretty much any entertainment center, and benefits from a large and vibrant development community. You can even get enclosures that will dress the Linux single-board computer up like a miniature version of your favorite retro console. But what about the old school PC gamers who want to relive their glory days in a palm-sized package? Well, if you’ve got a 3D printer, [fantasticmrdavid] might have just the solution for you . This second iteration of his printable Raspberry Pi enclosure is designed to look like the 286 desktop that he had in his youth, complete with a functional “floppy drive” in the front that takes an SD card. With a 3.5 inch MPI3508 LCD up in the “monitor” and a copy of DOSBox on the SD card, you’re well on your way to booting up a copy of Windows 3.11 or building some contraptions in The Incredible Machine . While the ext

This week Jonathan Bennett and Dan Lynch talk once again with Neal Gompa of Fedora, CentOS, openSUSE and more. This time the focus is Fedora, with sprinklings of Immutable Linux, KDE 6, and the new Linux stack of Pipewire, Portals, and Wayland. Neal gives us a rundown of what exactly makes Fedora Atomic so interesting, and why you probably don’t want it running on your desktop. But in a computer lab, or on a public machine? Fedora Atomic might be exactly what you need. Up next there’s Pipewire, the userspace sound server that replaces Pulseaudio and Jack. Should we think of Pipewire as Jack 3.0? And what’s the secret to getting really reliable low-latency performance for Pipewire in Fedora? It might not be what you expect. There’s a popular rant online, that Wayland breaks everything. And for years, that’s been a relatively accurate statement, in that Wayland hasn’t been ready for prime-time. Fedora 40 has gone all in on the belief that Wayland’s time has come, with KDE and Gnome n

When you think of a logic analyzer today, you might think of a little USB probe that can measure a few signals and decoding for various serial buses. But actual logic analyzers were high-speed multichannel hardware with sophisticated ways to clock and trigger. [Tom] picked up an HP1670G on the surplus market and was impressed that it could sample 136 channels at 500 MHz. The circa-2000 machine has a front panel, but if you really wanted to use it, you wanted to use an X terminal. [Tom] shows us how that works with modern Linux software. In X/11 parlance, the terminal is the server, and the remote computer is the client. In the old days, when people weren’t so obsessed with security, running applications from multiple clients on a single server was easy. These days, most Linux distributions have made the X/11 system little more than a display driver. Logging into a remote system usually requires some hoops. However, [Tom] went with a different approach. Using socat, he routes incomi

The Mandelbrot set is — when visualized with some colors — an interesting shape with infinite detail. While the patterns are immediately obvious to the human eye, anyone who’s run one can tell you that they’re pretty computationally expensive to produce. Fortunately, as with many things in graphics, rendering the Mandelbrot set can be easily parallelized. That’s what [rak277] and [ir93] demonstrate in their RP2040-based finals project . Computron, as they call it, is a network of Raspberry Pi Picos that work together to compute a visualization of the Mandelbrot set and show it on a VGA display. The Computron is made of two or more “math units” and one “projection unit”. The math units communicate over a shared I²C bus with the projection unit to first divide the workload and then compute their share of the work. This project shows both the strengths and limitations of parallel computation. It makes use of multiple math units on a highly parallelizable workload, but as more math unit

Last time, we looked at some powerful trigger modes found on many modern scopes, including the Rigol DHO900 series we used as an example. Those triggers were mostly digital or, at least, threshold-based. This time, we’ll look at some more advanced analog triggers as well as a powerful digital trigger that can catch setup and hold violations. You can find the Raspberry Pi code to create the test waveforms online. In addition to software, you’ll need to add some simple components to generate the analog waveform. In particular, pin 21 of the Pi connects to  2uF capacitor through a 10K resistor. The other side of the capacitor connects to ground. In addition, pin 22 connects directly to the capacitor, bypassing the 10K resistor. This allows us to discharge the capacitor quickly. The exact values are not especially important. Runt Triggers A runt pulse is one that doesn’t have the same voltage magnitude as surrounding pulses. Sometimes, this is due to a bus contention, for example. Im