Kritik sah

Radiation-induced volumetric expansion (RIVE) is a concern for any concrete structures that are exposed to neutron flux and other types of radiation that affect crystalline structures within the aggregate. For research facilities and (commercial) nuclear reactors, RIVE is generally considered to be one of the factors that sets a limit on the lifespan of these structures through the cracking that occurs as for example quartz within the concrete undergoes temporary amorphization with a corresponding volume increase. The significance of RIVE within the context of a nuclear power plant is however still poorly studied. A recent study by [Ippei Maruyama] et al. as published in the  Journal of Nuclear Materials placed material samples in the LVR-15 research reactor in the Czech Republic to expose them to an equivalent neutron flux. What their results show is that at the neutron flux levels that are expected at the biological shield of a nuclear power plant, the healing effect from rec...

Typewriters aren’t really made anymore in any major quantity, since the computer kind of rained all over its inky parade. That’s not to say you can’t build one yourself though, as [Toast] did in a very creative fashion. After being inspired by so many typewriters on YouTube, [Toast] decided they simply had to 3D print one of their own design. They decided to go in a unique direction, eschewing ink ribbons for carbon paper as the source of ink. To create a functional typewriter, they had to develop a typebar mechanism to imprint the paper, as well as a mechanism to move the paper along during typing. The weird thing is the letter selection—the typewriter doesn’t have a traditional keyboard at all. Instead, you select the letter of your choice from a rotary wheel, and then press the key vertically down into the paper. The reasoning isn’t obvious from the outset, but [Toast] explains why this came about after originally hitting a brick wall with a more traditional design. If you’ve eve...

Most of us learned to design circuits with schematics. But if you get to a certain level of complexity, schematics are a pain. Modern designers — especially for digital circuits — prefer to use some kind of hardware description language. There are a few options to do similar things with PCB layout, including tscircuit. There’s a walk-through for using it to create an LED matrix and you can even try it out online, if you like. If you’re more of a visual learner, there’s also an introductory video you can watch below. The example project imports a Pico microcontroller and some smart LEDs. They do appear graphically, but you don’t have to deal with them graphically. You write “code” to manage the connections. For example: <trace from={".LED1 .GND"} to="net.GND" /> If that looks like HTML to you, you aren’t wrong. Once you have the schematic, you can do the same kind of thing to lay out the PCB using footprints. If you want to play with the actual design, y...

This week, Jonathan Bennett and Dan Lynch chat with Peter van Dijk about PowerDNS! Is the problem always DNS? How did PowerDNS start? And just how big can PowerDNS scale? Watch to find out! https://github.com/PowerDNS/ https://github.com/Habbie https://github.com/voorkant/ https://7bits.nl/journal/ Did you know you can watch the live recording of the show right on our YouTube Channel ? Have someone you’d like us to interview? Let us know, or contact the guest and have them contact us! Take a look at the schedule here . Direct Download in DRM-free MP3. If you’d rather read along, here’s the transcript for this week’s episode . Places to follow the FLOSS Weekly Podcast: Spotify RSS Theme music: “Newer Wave” Kevin MacLeod (incompetech.com) Licensed under Creative Commons: By Attribution 4.0 License from Blog – Hackaday https://ift.tt/4qFZzxB

The future of healthy indoor plants, courtesy of AI. (Credit: [ Liam ]) Like so many of us, [Liam] has a big problem. Whether it’s the curse of Brown Thumbs or something else, those darn houseplants just keep dying despite guides always telling you how  incredibly easy it is to keep them from wilting with a modicum of care each day, even without opting for succulents or cactuses. In a fit of despair [Liam] decided to pin his hopes on what we have come to accept as the Savior of Humankind, namely ‘AI’, which can stand for a lot of things, but it’s definitely really smart and can even generate pretty pictures, which is something that the average human can not. Hence it’s time to let an LLM do all the smart plant caring stuff with ‘PlantMom’. Since LLMs (so far) don’t come with physical appendages by default, some hardware had to be plugged together to measure parameters like light, temperature and soil moisture. Add to this a grow light & a water pump and all that remained ...

A quadrature encoder provides a way to let hardware read movement (and direction) of a shaft, and they can be simple, effective, and inexpensive devices. But [Paulo Marques] observed that when it comes to reading motor speeds with them, what works best at high speeds doesn’t work at low speeds, and vice versa. His solution? PicoEncoder is a library providing a lightweight and robust method of using the Programmable I/O (PIO) hardware on the RP2040 to get better results, even (or especially) from cheap encoders, and do it efficiently . The results of the sub-step method (blue) resemble a low-pass filter, but is delivered with no delay or CPU burden. The output of a quadrature encoder is typically two square waves that are out of phase with one another. This data says whether a shaft is moving, and in what direction . When used to measure something like a motor shaft, one can also estimate rotation speed. Count how many steps come from the encoder over a period of time, and use tha...

On a Commodore 64, the computer is normally connected to a monitor with one composite video cable and to an audio device with a second, identical (although uniquely colored) cable. The signals passed through these cables are analog, each generated by a dedicated chip on the computer. Many C64 users may have accidentally swapped these cables when first setting up their machines, but [Matthias] wondered if this could be done purposefully — generating video with the audio hardware and vice versa . Getting an audio signal from the video hardware on the Commodore is simple enough. The chips here operate at well over the needed frequency for even the best audio equipment, so it’s a relatively straightforward matter of generating an appropriate output wave. The audio hardware, on the other hand, is much less performative by comparison. The only component here capable of generating a fast enough signal to be understood by display hardware of the time is actually the volume register, although...

It’s not unusual for redundant satellites, rocket stages, or other spacecraft to re-enter the earth’s atmosphere. Usually they pass unnoticed or generate a spectacular light show, and very rarely a few pieces make it to the surface of the planet. Coming up though is something entirely different, a re-entry of a redundant craft in which the object in question might make it to the ground intact . To find out more about the story we have to travel back to the early 1970s, and Kosmos-482. It was a failed Soviet Venera mission, and since its lander was heavily over-engineered to survive entry into the Venusian atmosphere there’s a fascinating prospect that it might survive Earth re-entry. This model of the earlier Venera 7 probe shows the heavy protection to survive entry into the Venusian atmosphere. Emerezhko, CC BY-SA 4.0 . At the time of writing the re-entry is expected to happen on the 10th of May, but as yet due to its shallow re-entry angle it is difficult to predict where it mi...

If you’ve dealt with reactance, you surely know the two equations for computing inductive and capacitive reactance. But unless you’ve really dug into it, you may only know the formula the way a school kid knows how to find the area of a circle. You have to have a bit of higher math to figure out why the equation is what it is. [Old Hack EE] wanted to figure out why the formulas are what they are, so he dug in and shared what he learned in a video you can see below. The key to understanding this is simple. The reactance describes the voltage over the current through the element, just like resistance. The difference is that a resistance is just a single number. A reactance is a curve that gives you a different value at different frequencies. That’s because current and voltage are out of phase through a reactance, so it isn’t as easy as just dividing. If you know calculus, the video will make a lot of sense. If you don’t know calculus, you might have a few moments of panic, but you ca...

Roughly the size of a Tic Tac container, this project packs a punch in a compact package. [Matt] sent in this beautifully documented pocket device that brings back great memories of texting on early cellphones. The EclairM0’s firmware is written in TinyGo, a language he hadn’t used before but found perfect for a microcontroller project where storage space is tight. The 14-button input mimics early phone keypads, using multi-tapping and combo key presses to offer various functions. The small SSD1306 OLED display is another highlight. Building on an earlier CircuitPython project, [Matt] optimized the screen’s performance, speeding up its response time for a snappy user experience. The battery picked was only 3 mm thick, however the protection circuity on the battery added another 2 mm so he moved that protection circuity to the main PCB itself to keep it as thin as initially planned. Weighing just 15 grams, this lightweight device runs on a SAMD21 microcontroller, which supports USB ...

The Star Trek tricorder was a good example of a McGuffin. It did anything needed to support the plot or, in some cases, couldn’t do things also in support of the plot. We know [SirGalaxy] was thinking about the tricorder when he named the Tinycorder , but the little device has a number of well-defined features. You can see a brief video of it working below the break. The portable device has a tiny ESP32 and a battery. The 400×240 display is handy, but has low power consumption. In addition to the sensors built into the ESP32, the Tinycorder has an AS7341 light sensor, an air quality sensor, and a weather sensor. An odd combination, but like its namesake, it can do lots of unrelated things. The whole thing goes together in a two-part printed case. This is one of those projects where you might not want an exact copy, but you very well might use it as a base to build your own firmware. Even [SirGalaxy] has plans for future developments, such as adding a buzzer and a battery indicator....

Recycling 3D filament is a great idea in theory, and we come across homemade filament extruders with some regularity, but they do have some major downsides when it comes to colored filaments. If you try to recycle printer waste of too many different colors, you’ll probably be left with a nondescript gray or brown filament. Researchers at Western University, however, have taken advantage of this pigment mixing to create colors not found in any commercial filament ( open access paper ). They started by preparing samples of 3D printed waste in eight different colors and characterizing their spectral reflectance properties with a visible-light spectrometer. They fed this information into their SpecOptiBlend program (open source, available here ), which optimizes the match between a blend of filaments and a target color. The program relies on the Kubelka-Munk theory for subtractive color mixing, which is usually used to calculate the effect of mixing paints, and minimizes the difference ...

In the early days of computing, and well into the era where home computers were common but not particularly powerful, programming these machines was a delicate balance of managing hardware with getting the most out of the software. Memory had to be monitored closely, clock cycles taken into account, and even video outputs had to be careful not to overwhelm the processor. This can seem foreign in the modern world where double-digit gigabytes of memory is not only common, it’s expected, but if you want to hone your programming skills there’s no better way to do it than with the limitations imposed by something like a retro computer or a Raspberry Pi Pico . This project is called Kaleidoscopio, built by [Linus Åkesson] aka [lft] and goes deep into the hardware of the Pi Pico in order to squeeze as much out of the small, inexpensive platform as possible. The demo is written with 17,000 lines of assembly using the RISC-V instruction set. The microcontroller has two cores on it, with one c...

One of the most paradoxical aspects of creating art is the fact that constraints, whether arbitrary or real, and whether in space, time, materials, or rules, often cause creativity to flourish rather than to wither. Picasso’s blue period, Gadsby  by Ernest Vincent Wright, Tetris, and even the Volkswagen Beetle are all famous examples of constraint-driven artistic brilliance. Similarly, in the world of electronics we can always reach for a microcontroller but this project from [Peter] has the constraint of only using passive components, and it is all the better for it . The project is a lockbox, a small container that reveals a small keypad and the associated locking circuitry when opened. When the correct combination of push buttons is pressed, the box unlocks the hidden drawer. This works by setting a series of hidden switches in a certain way to program the combination. These switches are connected through various diodes to a series of relays, so that each correct press of a bu...

Looks like the Simpsons had it right again , now that an Australian radio station has been caught using an AI-generated DJ for their midday slot. Station CADA, a Sydney-based broadcaster that’s part of the Australian Radio Network, revealed that “Workdays with Thy” isn’t actually hosted by a person; rather, “Thy” is a generative AI text-to-speech system that has been on the air since November. An actual employee of the ARN finance department was used for Thy’s voice model and her headshot, which adds a bit to the creepy factor. The discovery that they’ve been listening to a bot for months apparently has Thy’s fans in an uproar, although we suspect that the media doing the reporting is probably more exercised about this than the general public. Radio stations have used robo-jocks for the midday slot for ages, albeit using actual human DJs to record patter to play between tunes and commercials. Anyone paying attention over the last few years probably shouldn’t be surprised by this de...

Space X Starship firing its many Raptor engines. The raptor pioneered the new generation of methalox. (Image: Space X) Go back a generation of development, and excepting the shuttle-derived systems, all liquid rockets used RP-1 (aka kerosene) for their first stage. Now it seems everybody and their dog wants to fuel their rockets with methane. What happened? [Eager Space] was eager to explain in recent video , which you’ll find embedded below. At first glance, it’s a bit of a wash: the density and specific impulses of kerolox (kerosene-oxygen) and metholox (methane-oxygen) rockets are very similar. So there’s no immediate performance improvement or volumetric disadvantage, like you would see with hydrogen fuel. Instead it is a series of small factors that all add up to a meaningful design benefit when engineering the whole system. Methane also has the advantage of being a gas when it warms up, and rocket engines tend to be warm. So the injectors don’t have to worry about atomizing...

[Sean Boyce] has been busy building board games. Specifically, an electronic strategy boardgame that is miraculously also compatible with Settlers of Catan. [Sean’s] game is called Calculus. It’s about mining asteroids and bartering. You’re playing as a corporation attempting to mine the asteroid against up to three others doing the same. Do a good job of exploiting the space-based resource, and you’ll win the game. Calculus is played on a board made out of PCBs. A Xiao RP2040 microcontroller board on the small PCB in the center of the playfield is responsible for running the show. It controls a whole ton of seven-segment displays and RGB LEDs across multiple PCBs that make up the gameboard. The lights and displays help players track the game state as they vie for asteroid mining supremacy. Amusingly, by virtue of its geometry and some smart design choices, you can also use [Sean]’s board to play Settlers of Catan. He’s even designed a smaller, cheaper travel version, too. We do se...

If you build electronics, you will eventually need a coil. If you spend any time winding one, you are almost guaranteed to think about building a coil winder. Maybe that’s why so many people do. [Jtacha] did a take on the project , and we were impressed — it looks great. The device has a keypad and an LCD. You can enter a number of turns or the desired inductance. It also lets you wind at an angle. So it is suitable for RF coils, Tesla coils, or any other reason you need a coil. There are a number of 3D printed parts, so this doesn’t look like an hour project. Luckily, none of the parts are too large. The main part is 2020 extrusion, and you will need to tap the ends of some of the pieces. There is a brief and strangely dark video in the post if you want to see the machine in operation. The resulting coil looked good, especially if you compare it to how our hand-wound ones usually look. While most of the coil winders we see have some type of motor , that’s not a necessity . fr...

The self-propelled zip fastener uses a worm gear to propel itself along the teeth. (Credit: YKK) At first glance the very idea of a zipper that unzips and zips up by itself seems somewhat ridiculous. After all, these contraptions are mostly used on pieces of clothing and gear where handling a zipper isn’t really sped up by having an electric motor sluggishly move through the rows of interlocking teeth. Of course, that’s not the goal of YKK, which is the world’s largest manufacturer of zip fasteners. The demonstrated prototype ( original PR in Japanese) shows this quite clearly, with a big tent and equally big zipper that you’d be hard pressed to zip up by hand. The basic application is thus more in industrial applications and similar, with one of the videos, embedded below, showing a large ‘air tent’ being zipped up automatically after demonstrating why for a human worker this would be an arduous task. While this prototype appears to be externally powered, adding a battery or su...

While most hams and hackers have at least heard of Heathkit, most people don’t know the strange origin story of the legendary company. [Ham Radio Gizmos] takes us all through the story . In case you don’t remember, Heathkit produced everything from shortwave radios to color TVs to test equipment and even computers. But, for the most part, when you bought something from them, you didn’t get a finished product. You got a bag full of parts and truly amazing instructions about how to put them together. Why? Well, if you are reading Hackaday, you probably know why. But some people did it to learn more about electronics. Others were attracted by the lower prices you paid for some things if you built them yourself. Others just liked the challenge. But Heathkit’s original kit wasn’t electronic at all. It was an airplane kit. Not a model airplane, it was an actual airplane. Edward Heath sold airplane kits at the affordable price around $1,000. In 1926, that was quite a bit of money, but appa...

Sometimes, a flat display just won’t cut it. If you’re looking for something a little rounder, perhaps your vision could persist in in looking at [lhm0]’s rotating LED sphere RP2040 POV display . As you might have guessed from that title, this persistence-of-vision display uses an RP2040 microcontroller as its beating (or spinning, rather) heart. An optional ESP01 provides a web interface for control. Since the whole assembly is rotating at high RPM, rather than slot in dev boards (like Pi Pico) as is often seen, [lhm0] has made custom PCBs to hold the actual SMD chips. Power is wireless, because who wants to deal with slip rings when they do not have to? The LED-bending jig is a neat hack-within-a-hack. [lhm0] has also bucked the current trend for individually-addressable LEDs, opting instead to address individual through-hole RGB LEDs via a 24-bit shift-register. Through the clever use of interlacing, those 64 LEDs produce a 128 line display. [lhm0] designed and printed an LED-...

In the realm of computer science, it’s hard to go too far without encountering hashing or hash functions. The concept appears throughout security, from encryption to password storage to crypto, and more generally whenever large or complex data must be efficiently mapped to a smaller, fixed-size set. Hashing makes the process of looking for data much faster for a computer than performing a search and can be incredibly powerful when mastered. [Malte] did some investigation into hash functions and seems to have found a method called Fibonacci hashing that not only seems to have been largely forgotten but which speeds up this lookup process even further. In a typical hashing operation, the data is transformed in some way, with part of this new value used to store it in a specific location. That second step is often done with an integer modulo function. But the problem with any hashing operation is that two different pieces of data end up with the same value after the modulo operation is...