Kritik sah

As far as hobbies go, ham radio tends to be on the more expensive side. A dual-band mobile radio can easily run $600, and a high-end HF base station with the capability of more than 100 watts will easily be in the thousands of dollars. But, like most things, there’s an aspect to the hobby that can be incredibly inexpensive and accessible to newcomers. Crystal radios, for example, can be built largely from stuff most of us would have in our parts drawers, CW QRP radios don’t need much more than that, and sometimes even the highest-performing antennas are little more than two lengths of wire . For this specific antenna, [W3CT] is putting together an inverted-V which is a type of dipole antenna. Rather than each of the dipole’s legs being straight, the center is suspended at some point relatively high above ground with the two ends closer to the earth. Dipoles, including inverted-Vs, are resonant antennas, meaning that they don’t need any tuning between them and the radio so the only th...

A decade ago, [Jouke Waleson] bought a Dutch ‘model 1950’ PTT (The Dutch Postal  Service) rotary-dial telephone of presumably 1950s vintage manufactured by a company called Standard Electric, and decided it would be neat to  hack it to function as a Bluetooth hands-free device . Looking at the reverse, however, it is stamped “10.65” on the bottom, so maybe it was made as recently as 1965, but whatever, it’s still pretty old-tech now. A well-specified transformer? The plan was to utilise ESP32 hardware with the Espressif HFP stack to do all the Bluetooth heavy lifting. [Jouke] did find out the hard way that this is not a commonly-trodden path in hackerland, and working examples and documentation were sparse, but the fine folks from Espressif were on hand via GitHub to give him the help he needed. After ripping into the unit, it was surprisingly stuffed inside there. Obviously, all the switching, even the indication, was purely electromechanical, which should be no surpri...

Volumetric displays are simply cool. Throw some LEDs together, take advantage of persistence of vision, and you’ve really got something. [Nick Electronics] shows us how its done with his neat little volumetric lamp build. The concept is simple. [Nick] built a little device to spin a little rectangular array of LEDs. A small motor in the base provides the requisite rotational motion at a speed of roughly 6000 rpm. To get power to the LEDs while they’re spinning, the build relies on wire coils for power transmission, instead of the more traditional technique of using slip rings. The build doesn’t do anything particularly fancy—it just turns on the whole LED array and spins it. That’s why it’s a lamp, rather than any sort of special volumetric display. Still, the visual effect is nice.  We’ve seen some other highly capable volumetric displays before, though. Video after the break. from Blog – Hackaday https://ift.tt/nfOSHkq

Face it, we’ve all at some time or other looked at our hot glue guns, and thought “I wonder if I could use that for 3D printing!”. [Proper Printing] didn’t just think it, he’s made a working hot glue 3D printer . As you’d expect, it’s the extruder which forms the hack here. A Dremel hot glue gun supplies the hot end, whose mains heater cartridge is replaced with a low voltage one with he help of a piece of brass tube. He already has his own design for an extruder for larger diameters, so he mates this with the hot end. Finally the nozzle is tapped with a thread to fit an airbrush nozzle for printing, and he’s ready tp print. With a much lower temperature and an unheated bed it extrudes, but it takes multiple attempts and several redesigns of the mechanical parts of the extruder before he finally ended up with the plastic shell of the glue gun as part of the assembly. The last touch is a glue stick magazine that drops new sticks into a funnel on top of the extruder, and it’s printing...

While most operating systems are written in C and C++, KolibriOS is written in pure x86 assembly and as a result small and lightweight enough to run off a standard 1.44 MB floppy disk, as demonstrated in a recent video by [Michael]. Screenshot of the KolibriOS desktop on first boot with default wallpaper. As a fork of 32-bit MenuetOS back in 2004, KolibriOS has since followed its own course, sticking to the x86 codebase and requiring only a modest system with an i586-compatible CPU, 8 MB of RAM and VESA-compatible videocard. Unlike MenuetOS’ proprietary x86_64 version, there’s no 64-bit in KolibriOS, but at this level you probably won’t miss it. In the video by [Michael], the OS boots incredibly fast off both a 3.5″ floppy and a CD-ROM, with the CD-ROM version having the advantage of more software being provided with it, including shareware versions of DOOM and Wolfenstein 3D . Although web browsers (e.g. Netsurf) are also provided, [Michael] did not get Ethernet working, tho...

From the 60s to perhaps the mid-00s, the path to musical stardom was essentially straight with very few forks. As a teenager you’d round up a drummer and a few guitar players and start jamming out of a garage, hoping to build to bigger and bigger venues. Few people made it for plenty of reasons, not least of which was because putting together a band like this is expensive. It wasn’t until capable electronic devices became mainstream and accepted in popular culture in the last decade or two that a few different paths for success finally opened up, and this groovebox shows just how much music can be created this way with a few straightforward electronic tools. The groovebox is based on a Raspberry Pi Pico 2 and includes enough storage for 16 tracks with a sequencer for each track, along with a set of 16 scenes. Audio plays through PCM5102A DAC module, with a 160×128 TFT display and a touch-sensitive pad for user inputs. It’s not just a device for looping stored audio, though. There’s ...

All your Nintendo Alarmo are belong to mew~ (Credit: GaryOderNichts, Blogspot) Most of us will probably have seen Nintendo’s latest gadget pop up recently. Rather than a Switch 2 announcement, we got greeted with a Nintendo-branded alarm clock. Featuring a 2.8″ color LCD and a range of sensors, it can detect and respond to a user, and even work as an alarm clock for the low, low price of €99. All of which takes the form of Nintendo-themed characters alongside some mini-games. Naturally this has led people like [Gary] to buy one to see just how hackable these alarm clocks are. As can be expected from a ‘smart’ alarm clock it has 2.4 GHz WiFi connectivity for firmware and content download, as well as a 24 GHz millimeter wave presence sensor. Before [Gary] even had received his Alarmo, others had already torn into their unit, uncovering the main MCU (STM32H730ZBI6) alongside a 4 GB eMMC IC, as well as the MCU’s SWD pads on the PCB. This gave [Gary] a quick start with reverse-enginee...

This week, Jonathan Bennett and Dan Lynch chat with Josh Bressers, VP of Security at Anchore, and host of the Open Source Security and Hacker History podcasts. We talk security, SBOMs, and how Josh almost became a Sun fan instead of a Linux geek. – https://opensourcesecurity.io – https://hackerhistory.com – https://infosec.exchange/@joshbressers – https://anchore.com 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 from Blog – Hackaday https://ift.tt/6MCdeBL

Electrostatic motors are now common in MEMS applications, but researchers at the University of Wisconsin and spinoff C-Motive Technologies have brought macroscale electrostatic motors back. [via MSN/WSJ ] While the first real application of an electric motor was Ben Franklin’s electrostatically-driven turkey rotisserie, electromagnetic type motors largely supplanted the technology due to the types of materials available to engineers of the time. Newer dielectric fluids and power electronics now allow electrostatic motors to be better at some applications than their electromagnetic peers. The main advantage of electrostatic motors is their reduced critical materials use . In particular, electrostatic motors don’t require copper windings or any rare earth magnets which are getting more expensive as demand grows for electrically-powered machines. C-Motive is initially targeting direct drive industrial applications, and the “ voltage driven nature of an electrostatic machine ” means ...

Checking the voltages on a dead LED lightbulb. Best done by a professional, obviously. (Credit: The Doubtful Technician, YouTube) We have probably all seen the marketing blurbs on packaging and elsewhere promoting the amazing lifespan of LED lighting solutions. Theoretically you should be able to install a LED bulb in a fixture that used to hold that incandescent lightbulb which had to be replaced annually and have it last a decade or longer. Yet we seem to replace these LED bulbs much more often than that, with them suffering a range of issues. To get to the root cause of this, [The Doubtful Technician] decided to perform an autopsy on a range of dead lightbulbs which he got from a variety of sources and brands. One lamp is an Amazon-bought one by a seller who seems to have vanished, but was promised over 3 years of constant use. Other than the fun blinding of oneself while testing, this one was easy to diagnose, with a dodgy solder joint on a resistor in a MELF package. The nex...

Most of us using desktop computers, and plenty of us on laptops, have some sort of fan or pump installed in our computer to remove heat and keep our machines running at the most optimum temperature. That’s generally a good thing for performance, but comes with a noise pollution cost. It’s possible to build fanless computers, though, which are passively cooled by using larger heat sinks with greater thermal mass, or by building more efficient computers, or both. But sometimes even fanless designs can benefit from some forced air, so [Sasa] built this system for cooling fanless systems with fans . The main advantage of a system like this is that the fans on an otherwise fanless system remain off when not absolutely necessary, keeping ambient noise levels to a minimum. [Sasa] does have a few computers with fans, and this system helps there as well. Each fan module is WiFi-enabled, allowing for control of each fan on the system to be set up and controlled from a web page. It also can con...

The story of Commodore computers is one of some truly great machines for their time, and of the truly woeful marketing that arguably spelled their doom. But there’s another Commodore computing story, that of the machines we never received, many of which came close enough to production  that they might have made it. [Old VCR] has the story of one of these , and it’s a portable. It’s not a C64 like the luggable which did emerge, neither is it the legendary LCD portable prototype in the possession of our Hackaday colleague [Bil Herd]. Instead it’s a palmtop branded under licence from Toshiba, and since it’s a rare device even its home country of Japan the article gives us perhaps the only one we’ll ever see with either badge. The Commodore HHC-4 was announced at Winter CES 1983, and since it was never seen again it’s aroused some curiosity among enthusiasts. The article goes to some lengths to cross-reference the visible features and deduce that it’s in fact a Toshiba Pasopia Mini,...

With the latest release of Raspberry Pi OS (formerly Raspbian) the end of the X Window System has become reality , completing a years-long transition period. Although this change between display servers is not something which should be readily apparent to the casual user, the change from the client-server-based X11 protocol to the monolithic Wayland protocol has a number of implications. A major change is that with the display server and window manager no longer being separate units, features such as network transparency (e.g. remote X-sessions) are no longer a native feature, but have to be implemented separately by e.g. the Wayland compositor. For Raspberry Pi the transition to Wayland was based on the perceived efficiency and security benefits of the monolithic architecture, with the 2021 release of Raspbian (based on Debian Bullseye) testing the waters using the hybrid X11 window manager/Wayland compositor Mutter . This allowed for switching between X11 and Wayland without commi...

The annoying thing about commercial smart home gear is its lack of interoperability. HomeAssistant is very flexible though, and it’s easy to use all kinds of gear—even stuff you bodge together yourself. [Jeff Sandberg] demonstrates that ably with his project to use ancient 1990s burglar alarm sensors in his modern smarthome setup. The sensors in question are from an old GM Interlogix security system. The sensors themselves sit on doors or windows. They use magnets and a reed switch to sense if the door or window is opened. If so, they send out a radio message saying as much. All [Jeff] had to do was catch those messages and translate them for HomeAssistant. To listen in on the sensors, [Jeff] employed a Nooelec NESDR—a software defined radio that could pick up the 319.5 MHz signals. The NESDR runs a tool called RTL_433, which can decode the sensor signals, and spit out MQTT messages to interface with HomeAssistant. Much of the hard work was done already for [Jeff]—he just had to la...

The Quansheng UV-K5 is a popular handheld radio. It’s useful out of the box, but also cherished for its modification potential. [OM0ET] purchased one of these capable VHF/UHF radios, but got to hacking— as he wanted to use it as a desktop radio instead! This might just sound like a simple reshell, but there was actually a bit of extra work involved. Most notably, the Quansheng is designed to be tuned solely by using the keypad. For desktop use, though, that’s actually kind of a pain. Thus, to make life easier, [OM0ET] decided to whip up a little encoder control to handle tuning and other control tasks using an ESP32. This was achieved with help from one [OM0WT] and files for that are on Github . Other tasks involved finding a way to make the keypad work in a new housing, and how to adapt things like the audio and data module and the speaker to their new homes. Despite the original handheld being much smaller than the case used here, you’d be surprised how tight everything fits in th...

Computers were supposed to be personal, customizable, and cool. At times, in this cold modern world, we forget that. However, the cyberdeck scene is chock full of people building creative, original computers that suit their own tastes, aesthetics, and needs. [DIY Tinkerer] is one such individual, and he made the most of his woodworking skills when it came time to build his own cyberdeck! The technological basics are along the lines of what we’re used to in this field. The build is based around a Raspberry Pi 4, with [DIY Tinkerer] selecting an 8 GB model for his needs. It’s paired with a 9000 mAh onboard battery, and there’s a power jack on the front to let the thing run on anything from 5 to 20 volts DC. For ease of use, there’s a multi-memory card reader and several USB 3 ports available. The rest of the video focuses on the woodworking side of things. [DIY Tinkerer] shows us how he managed to build a new housing out of a rugged plastic case that would also be practical to use. Th...

Seeing the unseen is one of the great things about using an infrared (IR) camera, and even the cheap-ish ones that plug into a smartphone can dramatically improve your hardware debugging game. But even fancy and expensive IR cameras have their limits, and may miss subtle temperature changes that indicate a problem. Luckily, there’s a trick that improves the thermal resolution of even the lowliest IR camera, and all it takes is a little tweak to the device under test and some simple math . According to [Dmytro], “lock-in thermography” is so simple that his exploration of the topic was just a side quest in a larger project that delved into the innards of a Xinfrared Xtherm II T2S+ camera. The idea is to periodically modulate the heat produced by the device under test, typically by ramping the power supply voltage up and down. IR images are taken in synch with the modulation, with each frame having a sine and cosine scaling factor applied to each pixel. The frames are averaged together...

A British journalistic trope involves the phrase “The pound in your pocket”, a derisory reference to the 1960s Prime Minister Harold Wilson’s use of it to try to persuade the public that a proposed currency devaluation wouldn’t affect them. Nearly six decades later not so many Brits carry physical pounds in their pockets as electronic transfers have become more prevalent, but the currency remains. So much so that the governor of the Bank of England has had to reassure the world that the pound won’t be replaced by a proposed “Britcoin” cryptocurrency should that be introduced. Normally matters of monetary policy aren’t within Hackaday’s remit, but since the UK is not the only country to mull over the idea of a tightly regulated cryptocurrency tied to their existing one, there’s a privacy angle to be considered while still steering clear of the fog of cryptocurrency enthusiasts. The problem is that reading the justification for the new digital pound from the Bank of England, it’s ver...

Problem solved? If the problem is supplying enough lithium to build batteries for all the electric vehicles that will be needed by 2030, then a new lithium deposit in Arkansas might be a resounding “Yes!” The discovery involves the Smackover Formation — and we’ll be honest here that half the reason we chose to feature this story was to be able to write “Smackover Formation” — which is a limestone aquifer covering a vast arc from the Rio Grande River in Texas through to the western tip of the Florida panhandle. Parts of the aquifer, including the bit that bulges up into southern Arkansas, bear a brine rich in lithium salts, far more so than any of the brines currently commercially exploited for lithium metal production elsewhere in the world. Given the measured concentration and estimated volume of brine in the formation, there could be between 5 million and 19 million tons of lithium in the formation; even at the lower end of the range, that’s enough to build nine times the number o...

Back in the summer our eye was caught by [Jazzy Jane]’s new signal generator, or perhaps we should say her new-to-her signal generator. It’s an Advance E1 from around 1950, and it was particularly interesting from here because it matches the model on the shelf above this bench. She’s back with a new video on the E1 , allowing us a further look inside it as she replaces a dead capacitor, gets its audio oscillator working, and upgrades its sockets. Treating us to a further peek inside the unit, first up is a leaky capacitor. Then a knotty question for old tech enthusiasts, to upgrade or not? The ancient co-ax connectors are out of place on a modern bench, so does originality matter enough to give it a set of BNC sockets? We’d tend to agree; just because we have some adapters for the unit here doesn’t mean it’s convenient. Following on from that is a period variable frequency audio mod which has failed, so out that comes and a little fault-finding is required to get the wiring of the au...

Venus hasn’t received nearly the same attention from space programs as Mars, largely due to its exceedingly hostile environment. Most electronics wouldn’t survive the 462 °C heat, never mind the intense atmospheric pressure and sulfuric acid clouds. With this in mind, NASA has been experimenting with the concept of a completely mechanical rover. The [Beardy Penguin] and a team of fellow students from the University of Southampton decided to try their hand at the concept— video after the break. The project was divided into four subsystems: obstacle detection, mechanical computer, locomotion (tracks), and the drivetrain. The obstacle detection system consists of three (left, center, right) triple-rollers in front of the rover, which trigger inputs on the mechanical computer when it encounters an obstacle over a certain size. The inputs indicate the position of each roller (up/down) and the combination of inputs determines the appropriate maneuver to clear the obstacle. [Beardy Penguin...