Kritik sah

The DIY Commodore 64 cartridge. (Credit: Linus Åkesson) When you want to write software for a system like the Commodore 64, the obvious and safe choice is to create an image that can be used with a tape or floppy drive emulator. Yet these come with the obvious disadvantage of loading time and manual steps, much like with the original hardware. Unfortunately, if you crave that instant-on experience that cartridges offer – courtesy of them being plugged directly into the system’s CPU bus – you better get an EE diploma to figure it all out. Or maybe not, as [Linus Åkesson] found out when he created a custom cartridge to boot his Commodordian project from. For the core of the cartridge a bit of stripboard was sufficient to interface with the C64’s cartridge slot. Despite being single-sided, all the required signals were on one side of the slot. These include the EXROM line that informs the system that a cartridge is present, the ROML line that informs the cartridge when the system i...

The world of Linux has seen some disquiet over recent weeks following the decision of Red Hat to restrict source code distribution for Red Hat Enterprise Linux (RHEL) to only their paying customers. We’re sure that there will be plenty of fall-out to come from this news, but what can be done if your project relies upon access to those Red Hat sources? The Red-Hat-derived Rocky Linux distro relies on access to RHEL source, so the news could have been something of a disaster. Fortunately for Rocky users though, they appear to have found a reliable way to bypass the restriction and retain access to those RHEL sources. Red Hat would like anyone wanting source access to pay them handsomely for the privilege, but the Rocky folks have spotted a way to bypass this. Using readily available cloud images they can spin up a RHEL system and use it to download their sources, and they can do this as an automated process. We covered this story as it unfolded last week , and it seemed inevitable th...

The number of satellites whizzing by over our heads at any moment is staggering, and growing at a rapid rate as new constellations are launched. But sometimes it’s the old birds that are the most interesting, as is the case with some obsolete but still functional military communications satellites, which thanks to a lack of forethought are largely unsecured and easily exploitable. And all that’s needed to snoop in on them is a cheap ham radio and something like this simple and portable satcom antenna . As proof of the global nature of the radio hobby, the design in the video below by Brit [Tech Minds] borrows heavily from previous work by Italian ham [Ivo Brugnera (I6IBE)], which itself was adapted to use 3D-printed parts in a German blog post a few years ago. The common thread is the use of tape measures for the elements of the aptly named turnstile antenna, a tried and true material for lightweight, foldable antennas that amateur radio enthusiasts have been using for years. The an...

Typically, most of the gears we use in our life are made of plastic or metal. However, wood gears can do just fine in some simple roles, and they’re utterly pleasant to make, as this video from [botto bie] demonstrates. With steady hands, it’s easy to make basic gears by hand with basic tools and a printer. You just need the help of a spur gear generator to produce the required outlines for you to follow. [botto bie] uses the online tool from Evolvent Design which will spit out DXF or SVG files as you desire. Basic woodworking techniques are used to produce the gears, and they prove simple and effective. A rack is produced by first applying a involute tooth template with paper to a rectangular piece of wood. A series of circular and table jigsaw operations are then used to cut out the required material to produce the rack. A variety of toothed gears are produced in a similar fashion. If you’re lacking a CNC machine or a 3D printer, this can be a great way to experiment. Bonus poin...

Microcontrollers are so powerful these days that you can build color handheld games with them that match or exceed what you’d ever get on the Game Boys and Game Gears of yesteryear. The Picopad aims to offer just this, in an open-source hackable format that’s friendly to experimenters. As you might have guessed from the name, the Picopad is based on the Raspberry Pi Pico and its RP2040 microcontroller. It features four face buttons and a D-pad, along with a small color LCD with a 320×240 resolution. There is also a microSD slot upon which programs can be stored, and also an expansion port with headers for a variety of IO from the RP2040 itself including both GPIOs, serial, I2C and analog input pins. The housing is constructed out of PCBs, with some cheerful gaming artwork adding a fun aesthetic. Development is via a custom C SDK, with support for Micropython as well. If you want to build your own and don’t fancy starting from scratch, kits are available online. We’ve seen some othe...

The Coleco Adam is one of the great might-have-beens of the 8-bit home computer era, with an impressive bundle and on-paper spec let down by bugs, hardware issues, and poor availability. It’s something of a footnote today but it seems Coleco did get something right as it had a great keyboard. [Nick Bild] has one, and he’s brought it into the 21st century with a USB interface . The interfacing is courtesy of a Teensy microcontroller board as in so many other keyboard projects, but what makes this extra-interesting is the way the Coleco keyboard speaks to the world. Instead of merely being a matrix peripheral as were so many of its contemporaries, Coleco created their own custom serial bus for Adam desktop peripherals called AdamNet, and thus the keyboard contains its own 6801 microcontroller to perform the interfacing. The Teensy then is a USB-to-AdamNet interface, and could we’re guessing be made to talk to other Coleco peripherals if they exist. You can see the keyboard in action b...

Regular hulled boats are all well and good for rowing and all, but if you wanna go fast, you’ve gotta cut your draft. [RCLifeOn] built a hydroplane design that skims on the very surface of the water, and thus travels very quickly as a result. That’s one way to film your projects. The build came about as [RCLifeOn] has an upcoming race which he wishes to win with speed and finesse. To that end, he 3D printed an RC hydroplane, using spray paint and spackle to waterproof the parts. It’s a trimaran design, with the large central hull connected to two pontoons via carbon fiber rods. Propulsion is via a triple-motor fan setup on the rear of the boat. The outer motors were initially used to steer the boat via variable thrust, which comes with zero drag penalty compared to a conventional rudder. However, they proved ineffective, and a servo driven rudder was used instead. Eventually, all three motors were reconfigured for forward thrust. The boat worked well when it was able to get up t...

[Helge Fyske (LA6NCA)] may not be an actual spy — then again, he may be; if he’s good at it, we wouldn’t know — but he has built a couple of neat vacuum tube spy radios in the past. And there’s no better test for such equipment than to haul it out into the field and try to make some contacts. But how do you power such things away from the bench? To answer that question, skip ahead to the 3:18 mark of the video below , where [Helge] shows off his whole retro rig, including the compact 250-volt power supply he built for his two-tube 80-m Altoids tin spy transceiver . In the shack, [Helge] powers it with a bench power supply of his own design to provide the high anode voltage needed for the tubes, as well as 12 volts for their heaters. Portable operations require a more compact solution, preferably one that can be run off a battery small enough to pack in. By building his power supply in a tin, [Helge] keeps to his compact build philosophy. But the circuit is all solid state, which is ...

Wheeled bikes are efficient machines, and most cycling speed and distance records are held by them. However, [The Q] has a taste for weirder creations that amuse perhaps more than they serve as viable transportation. His latest experiments revolve around tracked propulsion methods. The build is a wheelless bike that relies on long thin tracks mounted to a mountain bike frame. The tracks carriers are fabricated using steel box section fitted with cogged rollers. The tracks themselves are made using a pair of bicycle chains joined with welded steel bars. They’re fitted with slices of rubber cut out of traditional bike tires for grip. The rear track is driven from the bike’s pedals, while the front is merely left to run freely. By virtue of its wide, flat tracks, the bike actually stands up on its own. It’s capable of riding in a straight line at slow speed, albeit relatively noisily. Steering is limited by virtue of the flat tracks, which don’t operate well at an angle to the ground. ...

When you find yourself doing a lot of work in 3D modelling, you occasionally wish for something more capable than the humble two-dimensional mouse. A space mouse is a great tool in this regard, and [Salim Benbouziyane] was inspired to build his own. [Salim] started his work with research, by watching a teardown of a Connexion Space Navigator 3D mouse. This informed him of the basic functionality and the workings inside. The commercial product appears to use an optical sensor setup, but [Salim] decided to go with a magnetic sensor setup instead due to the parts he had on hand. Namely, a 3-axis magnetometer which seemed perfect for the task. The build uses a motion platform mounted on six springs which translates and rotates in three dimensions as required. The magnetometer is mounted on the platform above a stationary set of neodymium magnets. Thus, when the platform, and thus sensor, moves, the magnetometer’s output can be used to determine the motion of the platform and translate t...

Many of us grew up watching Star Trek, marvelling at the beautiful colorful interfaces on the computers that ran the Starship Enterprise. Today’s computer interfaces have certainly grown fancier since the Windows 3.1 and Mac System 7 days, but they’re still nowhere near that gorgeous. The Arwes framework aims to change that, at least where web apps are concerned. The framework is inspired by the cyberprep and synthwave aesthetics, while drawing from media like TRON: Legacy and Halo. You can get a peek at what it can do on the Arwes website, or look at how it runs on sites like SoulExtract or the Cyber Movie Database. It’s very much about glowing lines, 1980s computer sounds, and screens with animated text fills. It’s still in an alpha release, and likely isn’t yet ready for business-critical production use. It currently consists of a set of basic components that can be assembled into a functional futuristic website design, but you’ll need some experience to use the tools at ha...

If you’re a woodworker, you know the value of a good planer. A stout model will last a lifetime if properly cared for. [Process X] has now taken us behind the scenes of a Japanese factory that turns out quality planers to show us how it’s done.  The video starts at the forge, where steel is attached to soft iron to form a blank that will become the planer blade. This is proper blacksmithing, with autohammers and flames akimbo. It’s also a woodworking story, though, with the planer bodies themselves carefully prepared for the years of faithful service ahead. We get to see the raw wood roughed into shape and put through the thicknesser, along with the more interesting machining steps that carve out the angled pockets and the blade slot. The final assembly is great, too, particularly when the pins are nailed in to hold everything in place. The test is the icing on the cake, in which the planer peels a perfect contiguous strip from a long piece of lumber. It’s still very much a man...

It’s pretty easy to program the Raspberry Pi Pico in Python, or you can use C or C++ if you so desire. However, if you fancy the easy language of yesteryear, you might like PiccoloBASIC from [Gary Sims]. Putting it simply, piccoloBASIC is a BASIC interpreter that runs on the Raspberry Pi Pico. It features all the good bits of BASIC such as GOTO and GOSUB commands, that fancier languages kind of look down upon. It’s also got enough built-in routines to handle regular programming life, like sleeps, delays, a basic pseudorandom number source, trigonometric functions, and the ability to deal with floating point numbers. As far as microcontroller tasks go, it’s got rudimentary support for talking to GPIOs right now via the pinon and pinoff commands. However, it’s probably not the way to go if you want to bit-bang an SD card to within an inch of its speed rating. Down the road, [Gary] hopes to add support for features like the Pico’s I2C, SPI, and PIO hardware, along with networking proto...

While there are a lot of exciting electric vehicles finally coming to market, many of us feel nostalgic for the fossil cars of our youth. [Mihir Vardhan] restored his grandfather’s car with an unusual gas-to-EV conversion . While this conversion starts in the usual fashion by pulling out the gas engine, [Vardhan] takes a different tack than most by not just bolting an electric motor up to the transmission. Instead, he and his crew removed the head and pistons from the petrol burner and bolted the electric motor to the top on an L-shaped bracket. Using the timing belt to transfer power to the crankshaft, there is no need to figure out additional motors for the A/C compressor or power steering pump, greatly simplifying implementation. [Vardhan] did need to add a vacuum pump for the braking system and used a DC/DC converter to step down the 72V traction battery voltage to the 12V needed to charge the accessory battery. While it doesn’t exactly boast the performance of a Tesla, his barg...

If you’re working with 3.3V or 5V circuits, it’s easy for you to throw on a power or status LED here or there. [Tom Gralewicz] has found himself in a pickle, though, often working on projects with voltages like 36V or 48V. Suddenly, it’s no longer practical to throw an LED and a resistor on a line to verify if it’s powered or not. Craving this simplicity, [Tom] invented the Cheap Universal LED Driver, or CULD, to do the job instead. The CULD is designed as a simple LED indicator that will light up anywhere from 5V to 50V. It’s intended to be set-and-forget, requiring no fussing with different resistor values and no worries for the end user that excessive current draw will result. The key part ended up being the LV2862XLVDDCR – a cheap switching regulator. It can output 1 mA to 600 mA to drive one or several LEDs, and it can do so anywhere from a 4V to 60V input. Assemble this on a coin-sized PCB with some LEDs, and you’ve got your nifty do-everything indicator light. With a bridge r...

Typically, when most of us need a motor, we jump online to order one from a catalogue. [Levi Janssen] recently had to build his own for a college project , however, and learned a lot along the way. [Levi] whipped up his brushless DC motor design in OnShape . The motor has six coils in the stator, with the rotor carrying eight neodymium magnets. It’s an axial flux design, with the rotor’s magnets sitting above the coils. This makes construction very easy using 3D printed components. Axial flux motors also have benefits when it comes to power density and cooling, though optimization is outside the scope of [Levi]’s work here. [Levi]’s video covers both the development of the motor itself as well as the drive circuit, too. The latter is of key value if you’re interested in the vagaries of driving these motors, which is far more complex than running a simple brushed motor. He even gets his motor up to 12,500 rpm with his homebrewed drive circuit. Making your own motors can help you sol...

Most readers will be aware that a good way to extend WiFi range is to use a better antenna for those 2.4 GHz signals, but at the same time such high frequency hijinks have something of a reputation of being not for the faint-hearted. [Dereksgc] puts that reputation to the test by building a helical WiFi antenna — and if that weren’t enough — he also subjects it to a field test . In a real field, is there any other way? We’ve put both videos below the break, and you can find his helical antenna calculator on his website and the parametric CAD file for the scaffold in his GitHub repository. He first delivers a crash course in the fundamentals of helical antennas before diving into the construction, and even soldering on an impedance matching strip. The field testing involves setting up a base station with an FTP server on a phone, and connecting to it with a variety of antennas over increasing distance across farmland. We’ve characterised antennas in this way before, and it really d...

Despite how hostile to life some parts of the Earth’s continents are, humanity has enthusiastically endeavored over the course of millennia to establish at least a toehold on each of them. Yet humanity has barely ventured beyond the surface of the oceans which cover around three-quarters of the planet, with human activity in these bodies of water dropping off quickly along with the fading of light from the surface. Effectively, this means for all intents and purposes we have to this day not explored the vast majority of the Earth’s surface , due to over 70% of it being covered by water. As an ocean planet, much of Earth’s surface is covered by watery depths of multiple kilometers, with each 10 meters of water increasing the pressure by one atmosphere (1.013 bar), so that at a depth of one kilometer we’re talking about an intense 101 atmospheres. Over the past decades, the 1985 discovery of Titanic’s wreck approximately 3.8 kilometer below the surface of the Atlantic, the two year l...

Tesla coils are beautiful examples of high voltage hardware, throwing sparks and teaching us about all kinds of fancy phenomena. They can also be quite intimidating to build. [William Fraser], however, has come up with a design using just three components . It’s a simplified version of the “Slayer Exciter” design, which nominally features a transistor, resistor and LED, along with a coil, and runs on batteries. [William] learned that adding a capacitor in parallel with the batteries greatly improved performance, and allowed the removal of the LED without detriment. [William] also learned that the resistor was not necessary either, beyond starting the coil oscillating. The actual 3-component build uses a 10 farad supercapacitor as a power source, hooked up to a 2N3904 NPN transistor and an 85-turn coil. It won’t start oscillating on its own, but when triggered by a pulse of energy from a piezo igniter, it jerks into life. The optimized design actually uses the shape of the assembled ...

These days Bluetooth-based gadgets are everywhere, including for car and solar batteries. After connecting them up to the battery, you download the accompanying app on your smartphone, open it up and like magic you can keep tabs on your precious pile of chemistry that keeps things ticking along. Yet as [haxrob] discovered during an analysis , many of these devices will happily pass your location and other information along to remote servers. The device in question is a Bluetooth 4.0 Battery Monitor that is resold under many brands, and which by itself would seem to do just what it is said to do, from monitoring a battery to running crank tests. Where things get unpleasant is with the Battery Monitor 2 (BM2) mobile app that accompanies the device. It integrates a library called AMap which is “a leading provider of digital map in China” and part of Alibaba. Although the app’s information page claims that no personal information is collected, the data intercepted with Wireshark would be...

These days the dozen or so ECUs in an average car are joined by an infotainment system of some type, which are typically a large touch screen on the dashboard (the headunit) and possibly a couple of auxiliary units for the rear seats. These infotainment systems run anything from QNX to (Yocto) Linux or more commonly these days some version of Android. As [Eric McDonald] discovered with his 2021 Honda Civic , its headunit runs an archaic Android dating back to roughly 2012. While this offers intriguing options with gaining root access via decade-old exploits that the car manufacturer never fixed, as [Eric] notes, this is an advantage that anyone who can gain access to the car’s CAN buses via e.g. the headlights , a wireless access point , or even inject an exploit via ADB radio can use to their advantage. Essentially, these infotainment systems are massive attack surfaces with all of their wired and wireless interfaces, combined with outdated software that you as the vehicle owne...

The ESPBoy was first built as a hackable open-source game engine and handheld console for educational purposes. However, it’s also a platform that can readily support all kinds of other uses. You can even turn the humble handheld device into a working walkie talkie. The build relies on adding a SA868 transceiver module to the ESPBoy, along with a microphone, speaker, audio amplifier and antenna as supporting hardware. It then relies on the ESPBoy’s existing screen and buttons as a user interface for the radio. Assembled appropriately, it can then be used as a very basic and barebones walkie talkie for voice communication. You won’t get coded squelch or other useful features, but it’s enough to let you talk over the air with other handheld radio users. The SA868 module can transmit on a variety of frequency bands, but the video shows it operating in the UHF band around 433 MHz. With a power on the order of 1.8W, it should get you a few kilometers of transmission range in an open fiel...

Early on, railways primarily used wheels made of wood or iron. The former were cheap and relatively easy to manufacture, while the latter had far superior wear qualities. It may surprise you to learn, however, that some railways once used wheels made out of paper, as [Train of Thought] explains. The wheels were pioneered by a man known as Richard N. Allen, in the 19th century. The wheels were constructed by layering up hundreds of sheets of paper with glue, compacting them with a press, and allowing them to cure for a few weeks. The solid paper disks were then machined to size, and were drilled to accept bolts that attached metal plates for protection. The wheels were given a cast-iron hub and a steel rim for wear reasons. The benefit of the wheels was that their composite paper construction helped damp vibrations and noise from the wheels and rails. The North American Pullman railway ended up using the wheels for sleeper and dining carriages for the more luxurious ride they provide...

As auto manufacturers have brought self-driving features to their products, we’re told about how impressive their technologies are and just how much computing power is on board to make it happen. Thus it surprised us (and it might also surprise you too) that some level of self-driving can be performed by an Android phone. [ Mankaran Singh ] has the full details . It starts with the realization that a modern smartphone contains the necessary sensors to  perform basic self-driving, and then moves on to making a version of openpilot that can run on more than the few supported phones. It’s not the driver-less car of science fiction but one which performs what we think is SAE level 2 self driving, which is cruise control, lane centering, and collision warning. They take it out on the road in a little Suzuki on a busy Indian dual carriageway in the rain, and while we perhaps place more trust in meat-based driving, it does seem to perform fairly well Self driving features are codified...

There are few rites of programmer passage as iconic as writing your first parser. You might want to interpret or compile a scripting language, or you might want to accept natural-language-like commands. You need a parser. [Varunramesh] wants to show you parser combinators , a technique used to make practical parsers. But the demonstration using interactive code cells in the web page is nearly as interesting as the technique. Historically, you parse tokens, and this technique can do that too, but it can also operate directly on character streams if you prefer. The idea is related to recursive descent parsing, where you attempt to parse certain things, and if those things fail, you try again. There are ways to match in a fuzzy way using Levenshtein distance. That way, if the user enters a typo, you can often recover from it. You could probably implement other schemes for this, too, like soundex, if you were parsing names. These types of parsers do have some limitations, but they are ...

We all might dream of having an industrial robot arm at our disposal, complete with working controller that doesn’t need constant maintenance and replacement parts, and which is able to help us with other projects with only a minimum of coding or instruction. That’s a pipe dream for most of us, as without a large space, sufficient funding, or unlimited amounts of troubleshooting time we’ll almost always have to look for something smaller and simpler. Perhaps something even as small as this pocket-sized robotic arm . This isn’t actually the first time we’ve seen the MeArm; the small robot has been around since 2014 and has undergone a number of revisions and upgrades. Even this revision has been out for a little while now but this latest in the series is now available with a number of improvements over the older models. The assembly time required has been reduced from two hours to about 30 minutes and the hardware has even been fully open-sourced as well which allows virtually anyone ...

Cross-pollination between different industries can yield interesting innovations, and a few years ago [John Wiltrout] developed some non-slip meter probe adapters . He recently used our tips line to share some details that you won’t see elsewhere, letting us know how the idea came to be. It started with [John] being frustrated by issues that will sound familiar: probes did not always want to stay in place, and had a tendency to skid around at the slightest provocation. This behavior gets only more frustrating as boards and components get smaller. John was also frustrated by the general inability to reliably probe through barriers like solder masking, oxidation, and conformal treatments on circuit boards. The adapters attach to regular probe tips. At the time [John] was in the dental equipment service industry, and one day he received a visit from the Good Ideas Fairy. He got the idea to use one of the special tungsten carbide tipped dental burrs as a probe tip. The tips of thes...