Kritik sah

As strong and light as carbon fiber-epoxy composites are, the same can’t always be said of carbon-fiber reinforced 3D printer filaments. Of those that do improve over stock filament, the best performance comes from long, continuous strands, but the printers that can embed these are quite expensive. [MagicLAG], looking for a cheaper method, made something even stronger: prints reinforced with subsurface carbon-fiber cloth. They tried a few other methods first, including pausing the print and manually embedding carbon fiber strands, ironing strands into the finished part, and ironing carbon fiber cloth into the bottom layer. For the main method, though, he printed the test part in three pieces: a core part, and two outer shell layers. Between the core and the shell is a small gap, into which carbon-fiber cloth can be epoxied. Under good conditions (not using quick-setting epoxy), this mostly preserves the outer surface and dimensional accuracy. To test the various strengthening metho...

If you used a serious computer pre-IBM PC, there was a fair chance its operating system was CP/M. CP/M was a staple among 8080 and Z80 computers and while there were other versions, we’ll always associate CP/M with the Z-80. There was a CP/M made for the PC which used an 8088 (a hybrid 8-bit bus with a 16-bit 8086 core), but it was overwhelmed by MSDOS. However, there was another interesting version made for the 68000, and now [johnsonjh] has ported that over to create an early version of CP/M for 80386 protected mode . The Z-80 only had a 16-bit address bus, so it could only handle 64K of memory. It was common to “bank switch” some memory, and CP/M Plus could be made to understand that (for example, you might have 32K of common memory and three banks of 32K memory; you could address one bank at a time). However, the 386 had a full-blown memory management unit that could remap physical 4K memory pages to anywhere in a program’s virtual address space. Ordinary C...

In semiconductor technology, a base material like silicon is permanently modified to induce certain electrical behavior. In comparison a topological insulator material could be used to create temporary circuits using something like light exposure. An example of this is the Floquet topological state, which has long been theorized, but is now claimed to have been demonstrated in SnTe semiconductor material, per a paper by [F. Chassot] et al. in Nature Physics . The concept of topological insulators was first proposed in 1985, but proving their existence was hard. Recently photonic Floquet topological insulators (PFTIs) have gained interest , with experiments by [Qian Ma] et al. in 2025 as well as other teams confirming aspects of the theory. This recent publication by [Chassot] et al. would thus confirm that optical control of topological insulators is thus possible. At the core of this effect is the band inversion that results from the light pulses, with the change in conduction bei...

Reverse-engineered schematic of the IBM 604’s TR-3 module. (Credit: Ken Shirriff) Taking a break from ogling microscopic features in Intel’s semiconductor processors, [Ken Shirriff] is back to instead poking at decidedly macroscopic pluggable modules from the 1948 IBM 604 Electronic Calculator. This time around it’s one of the so-called trigger modules in the form of the TR-3 , which uses a flip-flop circuit to implement the timing signals and pulses that made the 604 work. This differs from the thyratron module that we covered previously . A thyratron is a high current switch and rectifier, which is useful more for the periphery of the computer system. These TR-3s on the other hand were used to implement the basic logic circuits, even if a flip-flop by itself seems rather boring, being just a circuit that toggles between two states. In this TR-3 module we find a 2033 dual triode design which thus increases density by having the two inverters of the flip-flop in th...

Circuit bending is a chaotic art. At its simplest, it can just involve making connections between random points on a circuit board to create weird sounds in musical hardware. Or, you can complicate things, get really specific with your hookups, and twist them with various sorts of modulation. [Simon the Magpie] has been working on something closer to the latter category, with his neat project to add MIDI to the circuit bending world.  The concept is straightforward enough. [Simon] has created a device that you place in line with your circuit bent connections, particularly those that create pitch bends with pots thanks to their variable resistance. You can then play your MIDI keyboard, and the device will vary the resistance in the circuit and bend the pitch at your command. [Simon] simply calls the device MIDI TO RESISTANCE, because that’s… precisely what it does, with the aid of a digital potentiometer. He then demonstrates it doing its thing on pitchbent toys, and it soun...

[David] has a young child who is clever enough to use a computer to play music, but he doesn’t quite want to hand over the mouse just yet. Thus, he set about building an electronic music player that could be operated in an altogether simpler fashion.  The build is based around an Arduino Nano — its job is to read RFID tags via an RC522 reader, with the tags themselves embedded in a series of small dolls belonging to [David]’s daughter. Upon reading the tag, the Arduino Nano chats over serial with a DFPlayer Mini module, which reads a playlist of MP3 files off of an SD card and plays them over a small 4 ohm speaker that [David] had laying around. It’s a simple build, with the components all neatly wrapped up in a handsome wooden case with a volume control and a skip button for if any one song becomes too annoying for a repeat listen. We’ve featured other builds in this vein before, too. There’s something satisfying about a music player with such a s...

As easy as it is to make a late 1980s-style game console using a modern microcontroller, there’s arguably more fun in doing things the traditional way. This is the challenge that [Throaty Mumbo] took upon himself when he embarked on his retro game console project, called simply the Game Console V2 . In the accompanying video the development process and other details are covered and demonstrated. Most notable perhaps are the proper cartridges with ROMs on a parallel bus rather than something like SD cards, and the absence of any modern ports including even VGA. This means only composite AV output like in the good old days of RF splitters and other assorted fun. The NTSC output signal is generated by an RP2350 MCU in the form of the PGA-shaped PGA2350 breakout board that’s wired into a 6-bit R-2R network for RGB332 output via the RCA jack, while audio is fed into a PCM5102A I2S DAC. For controllers you get 4-pin Bulgin SA2367 connectors and an N64-compatible protocol. It...

The Theremin is that classic electronic musical instrument that makes those weeee-ohhhhh noises which were so popular in mid-century science fiction movies. Mid-last-century, that is, because this century is just beginning. In any case, you could build one with old-school analog electronics, or you could go a more modern route, as [ericCycles] did. The build relies almost entirely on an ESP32 microcontroller with minimal supporting circuitry. Like any other Theremin, pitch and volume are controlled by moving hands closer or farther away from two antenna. In this case, the ESP32 uses its capacitive touch circuitry to detect effectively detect hand proximity to the two antenna in question, and uses those values to control the pitch and volume of a synthesized waveform. That waveform is then pumped out over the onboard digital-to-analog converter for playback on external speakers. If you want to build a simple Theremin-like instrument quickly and easily, it’s hard to beat the simpl...

About a month ago, we brought you word that the commercial rescue mission designed by Katalyst Space to save NASA’s Swift gamma-ray observatory had reached orbit and early indicators were looking good. Unfortunately, it didn’t take long for things to start going sideways, and up until very recently, the situation seemed pretty dire. But according to an interview with Katalyst’s CEO published yesterday by Ars Technica , the company has made some impressive progress on getting things back under control . For reasons unknown, the robotic vehicle started tumbling out of control last week. Shortly after that, mission controllers lost contact with Swift. After 24 hours without contact from the ground, the spacecraft automatically performed a sort of “hard reset” in an attempt to regain communications. That got it talking again, but somewhere along the way the craft overheated, which in turn cooked the control circuitry for the reaction wheels, which would usuall...

[Jumpor] lives in a part of India where the water infrastructure is a little frustrating to use. Water gets delivered to underground tanks outside of homes, and must then be regularly pumped into rooftop tanks prior to use inside the building. Typically, this pumping is handled manually—by switching on a pump and running it until water comes out of an overflow pipe to indicate the rooftop tank is full. [Jumpor] decided to improve this wasteful and time consuming process with a little automation project. The build is based around an ESP32 microcontroller. It’s hooked up to an ultrasonic sensor which can measure the water level inside the rooftop water tank. When the sensor detects the level descending below a set point, the microcontroller fires a relay to trigger the lift pump to fill up the tank. Once the sensor detects the tank is full, the pump is shut off, saving liters of water compared to waiting for water to pour out of the overflow as an indicator of the same. It’s...

There’s a new contender in the prosumer UV printer world up on Kickstarter , the HeyGears G1. This one’s particularly interesting as they’re explicitly marketing it as being able to produce full-color 3D prints along with the “print-on-anything” functionality we’ve come to expect from a UV flatbed printer. You get two choices of bed, with the larger being 420 mm x 320 mm x 130 mm. Hardly the largest build volume we’ve seen around here . You can fill that with up to 6 KG of UV ink/resin from its Epson-brand head in glorious full color and layers as small as 10 um. The ink isn’t super cheap — the CMYK kit looks to MRSP at 189 USD — but you aren’t locked in to expensive cartridges at least. HayGears sells ink in bottles, and you’re free to grab any other brand’s bottles if you want to risk it. The Kickstarter is ongoing, and it will be some time before backers get their printers. But we can report that the earl...

While we’ve largely settled on analog sticks and digital buttons for controlling video games, there’s all sorts of projects to create truly esoteric controllers that allow playing games in unique ways. This one from [sukolupo] lets you use data from standard bike trainers to get your virtual character moving. Called Deck de France, it maps the data coming from one of the supported bike trainers to a virtual controller which can then be “plugged in” to a gaming console of choice, in this case a Steam Deck mounted to the trainer’s handlebars. Although a bike trainer doesn’t have the same number of inputs as a modern gaming controller, it does have enough to play games like Rocket League. As you might expect, it’s also perfect for biking titles such as the Tour de France series. As far as unique controllers for video games go, this one is surely up in the rankings with a real trombone or a controller purpose-built for riding virtual horses . I...

Stewy is a very interesting robot, with some slightly odd kinematics. Its head is a Stewart platform, which is a common-enough 6-DOF actuated plate normally used with a fixed base. By connecting legs to the same servos running the Stewart platform, [JD] turned it into an adorable hexapod walker. The walker had a problem, though: it can’t feel its feet, and [JD] thinks that would make it much more mobile on uneven surfaces. So he got some resistors to turn the cheap servos in its legs into force-sensing actuators . Well, almost. He’s not actually putting strain gauges or anything like that into the legs; he’s just measuring the voltage drop across a resistor in series with the servos. Since the motors draw more current the more torque they’re putting out, he has a very quick and easy way to sense the current and thus the torque using good old Ohm’s law and an analog input on the microcontroller driving the robot. It’s a simple hack, but the data he...

Stream decks are very useful when you’re live on camera and you need to hit some complicated macro at a glance. However, there is sometimes a perception that commercial options are a touch expensive for what they are, an attitude which has spawned many DIY builds. [Fady Faheem] has developed just such a device of his own. Named Stream32, the build is intended to be simple to understand and adapt to one’s own individual workflow. Putting one together is as easy as buying a display, hooking it up to an ESP32, flashing the firmware, and then adding pages of shortcuts as desired. [Fady] has designed the firmware to be flexible with regards to screen choice — currently, it can be set up for a 4″ Waveshare LCD or a nice roomy 10.1″ display from Elecrow. Since it’s open source, adapting to a wider range of displays is a potential exercise for the builder. The great thing about custom stream decks is you have all the freedom in the world to customize them t...

Although generally glass isn’t associated with touch-sensitive surfaces, the addition of an ITO (indium tin oxygen) coating adds the exciting property of not only being transparent to the visible light part of the electromagnetic spectrum, but also of being electrically conductive. The logical result is that fine folk like [Sokol] simply had to use their newly acquired ITO-coated glass to make a button out of . Here the easy option is of course to just use it as a capacitive sensor where the conductive ITO layer is used for the capacitive charge and the glass provides the insulator, but here we see it demonstrated how to create a pressure-sensitive implementation instead. The measured conductivity on the ITO-coated glass in the video is pretty good, at just over 20 Ohm. This thus makes said capacitive button very easy to achieve. To make it a touch-sensitive button, two pieces of glass are used, with the ITO sides facing. Paper is used to create a spacer, after which the slight ...

We’ve likely all looked at a simple problem in our lives and thought that it would be an easy fix, only to realize that the project is enormously more complicated than we first realized. Whether that’s starting a home improvement project, doing a quick repair to a bicycle or car, or trying to install an obscure piece of software on a Linux machine, the amount of time we budget for these tasks often ends up woefully underestimated. [ Oscar ]’s night light needs to have its brightness set every night, and it seems easy enough to get a microcontroller to automate that, right ? Well, upon opening the small device, the first issue is that there is no labeling on any of the parts, so simply adding a jumper on to existing microcontroller pins without damaging anything wouldn’t easily be possible. Adding a secondary microcontroller is the next logical step, but the power supply in the night light is extremely underpowered so using even the smallest Raspberry Pi or off-t...

One thing our futuristic world is largely lacking in is droids and robot companions and the like. [solitary dev] is helping to rectify that problem by building a little robot called TongDou . As [solitary dev] tells it, TongDou is a “tiny open-source desktop gremlin.” An ESP32-S3 serves as TongDou’s brain, buried inside a tasteful brass tube chassis. An OLED display is TongDou’s face, and he uses a pair of wheels driven by gearmotors for locomotion. A speaker plays back pre-recorded voice lines, while a 24GHz radar and an IMU enables TongDou to keep track of the space it’s moving through. They are publishing the design files on Github so other makers can build their own if so desired. [solitary dev] hopes to develop TongDou into something to make a “workspace feel less dead.” It’s not dissimilar from the way studios used to use robots to liven up otherwise hackneyed movies and TV shows, and we could absolutely use some of that whimsy in...

The NES Advantage was a cool bit of hardware back in 1987, bringing an arcade stick to the home console gaming experience. Naturally they don’t get much use these days, unless of course they’ve been modded to work with modern systems, as [Aaron] has done. [Aaron]’s goals were straightforward. The stick should work with modern systems over Bluetooth, but the mod should not involve cutting the case or making any new holes. All controls, including Turbo and Slow Motion, still had to work, too, and there would be no adding extra buttons for configuration or control. To achieve this, [Aaron] whipped up a custom PCB which replaces the original cable attached to the NES Advantage. Power is via a small LiPo cell, charged via a TP4056 and paired with a TPS63900 buck-boost converter. An ESP32-WROOM-32E interfaces all the original controls, reading the stick’s CD4021 shift registers to do so. It then either emulates a Switch Pro Controller over Bluetooth Classic, for use ...

The elusive brainstem is a small, yet critical part of our brain: the slightest damage to it could prove fatal. But how it works is not fully understood today. Indian Scientists at SGBC (Sudha Gopalakrishnan Brain Centre) work to change that by producing the most detailed map of it ever seen . Instead of more costly methods, this map was created with a high-resolution microscope. Starting with three samples, (45W fetus, 9Y and 54Y) the brain stems were imaged using MRI and BFI (Block Face Imaging), then sliced into 20/40µm pieces, imaged, annotated using in-house software and added to the dataset. From a combination of these images, MRI and BFI scans, they created a 3D model of the brainstem that you can explore in your browser. The new research gives vital data needed for neurological research, and could help advance research on a wide range neurological diseases from Parkinson’s to Alzheimer’s. You can find the paper here , which has not yet been peer reviewed at time o...

Betacam is not the Betamax you may have had at home– it was a professional format that lived on into the 21st century, in the “SP” form. In many places, it would have been the last tape format in use. So it is perhaps understandable that [ldursw] decided to recreate an obsolete and unobtainable IC to save a Sony broadcast-grade editing Video Tape Recorder (VTR). Still mad, perhaps, but in a way we very much appreciate. The Sony BVW-75 VTR had an odd flaw where the output lacked colour, unless paused with dynamic tracking off. Then colour would appear, but only in odd stripes. Clearly the chroma circuit was at fault. Some sluthing found that a sync separator IC– that separates the sync pulses that keep everything moving together, if the name didn’t give it away– wasn’t behaving correctly. More sluthing found that the chip in question was no longer available. Luckily, the concept of a sync separator hasn’t quite given up the ghost, and ano...