Recently the ReactOS project released the much anticipated 0.4.15 update, making it the first major release since 2020. Despite what might seem like a minor version bump from the previous 0.4.14 release, the update introduces sweeping changes to everything from the kernel to the user interface and aspects like the audio system and driver support. Those who have used the nightly builds over the past years will likely have noticed a lot of these changes already.
Japanese input with MZ-IME and CJK font (Credit: ReactOS project)
A notable change is to plug-and-play support which enables more third party drivers and booting from USB storage devices. The Microsoft FAT filesystem driver from the Windows Driver Kit can now be used courtesy of better compatibility, there is now registry healing, and caching and kernel access checks are implemented. The latter improvement means that many ReactOS modules can now work in Windows too.
On the UI side there is a much improved IME (input method editor) feature, along with native ZIP archive support and various graphical tweaks.
Meanwhile since 0.4.15 branched off the master branch six months ago, the latter has seen even more features added, including SMP improvements, UEFI support, a new NTFS driver and improvements to power management and application support. All of this accompanied by many bug fixes, which makes it totally worth it to regularly check out the nightly builds.
If you think of a metal detector, you’re probably thinking of a fairly simple device with a big coil and a piercing whine coming from a tinny speaker. [mircemk] has built a more modern adaptation. It’s a metal detector you can use with your smartphone instead.
The metal detector part of the project is fairly straightforward as far as these things go. It uses the pulse induction technique, where short pulses are fired through a coil to generate a magnetic field. Once the pulse ends, the coil is used to detect the decaying field as it spreads out. The field normally fades away in a set period of time. However, if there is metal in the vicinity, the time to decay changes, and by measuring this, it’s possible to detect the presence of metal.
In this build, an ESP32 is in charge of the show, generating the necessary pulses and detecting the resulting field. It’s paired with the usual support circuitry—an op-amp and a few transistors to drive the coil appropriately, and the usual smattering of passives. The ESP32 then picks up the signal from the coil and processes it, passing the results to a smartphone via Bluetooth.
[Simon] wrote in to let us know about DingPong, his handheld portable Pong console. There’s a bit more to it than meets the eye, however. Consider for a moment that back in the 1970s playing Pong required a considerable amount of equipment, not least of which was dedicated electronics and a CRT monitor. What was huge (in more than one way) in the 70s has been shrunk down to handheld, and implemented almost entirely on modern e-waste in the process.
The 1970s would be blown away by a handheld version of Pong, made almost entirely from salvaged components.
DingPong is housed in an old video doorbell unit (hence the name) and the screen is a Sony Video Watchman, a portable TV from 1982 with an amazing 4-inch CRT whose guts [Simon] embeds into the enclosure. Nearly everything in the build is either salvaged, or scrounged from the junk bin. Components are in close-enough values, and power comes from nameless lithium-ion batteries that are past their prime but still good enough to provide about an hour of runtime. The paddle controllers? Two pots (again, of not-quite-the-right values) sticking out the sides of the unit, one for each player.
At the heart of DingPong one will not find any flavor of Arduino, Raspberry Pi, or ESP32. Rather, it’s built around an AY-3-8500 “Ball & paddle” (aka ‘Pong’) integrated circuit from 1977, which means DingPong plays the real thing!
We have seen Pong played on a Sony Watchman before, and we’ve also seen a vintage Pong console brought back to life, but we’re pretty sure this is the first time we’ve seen a Sony Watchman running Pong off a chip straight from the 70s. Watch it in action in the video (in German), embedded below.
Specifically, PCBWay has developed a workable glow-in-the-dark silkscreen material that can be applied to printed circuit boards. As a commercial board house, PCBWay hasn’t rushed to explain how precisely they pulled off this feat, but we don’t imagine that it involved anything more than adding some glow-in-the-dark powder to their usual silkscreen ink, but we can only speculate.
On [Botmatrix]’s end, his video steps through some neat testing of the performance of the boards. They’re tested using sensors to determine how well they glow over time.
It might seem like a visual gimmick, and to an extent, it’s just a bit of fun. But still, [Botmatrix] notes that it could have some practical applications too. For example, glow-in-the-dark silkscreen could be used to highlight specific test points on a board or similar, which could be instantly revealed with the use of a UV flashlight. It’s an edge case, but a compelling one. It’s also likely to be very fun for creating visually reactive conference badges or in other applications where the PCB plays a major cosmetic role.
USB Power Delivery is widely considered to be a good thing. It’s become relatively standard, and is a popular way for makers to easily power their projects at a number of specific, useful voltages. However, what you may not know is that it’s possible to get much more variable voltages out of some USB chargers out there. As [GreatScott!] explains, you’ll want to meet USB-C PPS.
PPS stands for Programmable Power Supply. It’s a method by which a USB-C device can request variable voltage and current delivery on demand. Unlike the Power Delivery standard, you’re not limited to set voltages at tiers of 5V, 9V, 15V and 20V. You can have your device request the exact voltage it wants, right from the charger. Commercially, it’s most typically used to allow smartphones to charge as fast as possible by getting the optimum voltage to plumb into the battery. However, with the right techniques, you can use PPS to get a charger to output whatever voltage you want, from 3.3 V to 21 V, for your own nefarious purposes. You can choose a voltage in 20 mV increments, and even set a current limit in 50 mA increments. Don’t go mad with power, now.
However, there’s a hitch. Unlike USB PD, there isn’t yet a whole ecosystem of $2 PPS breakout boards ready to gloop into your own little projects. As [GreatScott!] suggests, if you want to use PPS, you might want to take a look at the AP33772S IC. It’s a USB PD3.1 Sink Controller. You can command it over I2C to ask for the voltage and current you want. If that’s too hard, though, [CentyLab] has a solution on Tindie to get you going faster. It’s also got some exciting additional functionality—like USB-C AVS support. It offers higher voltage and more power, albeit with less resolution, but chargers with this functionality are quite obscure at this stage.
Let’s say you’ve got a big bare wall in your home, and you want some art on it. You could hang a poster or a framed artwork, or you could learn to paint a mural yourself. Or, like [Nik Ivanov], you could build a plotter called Mural, and get it to draw something on the wall for you.
The build is straightforward enough. It uses a moving carriage suspended from toothed belts attached to two points up high on the wall. Stepper motors built into the carriage reel the belts in and out to move it up and down the wall, and from side to side. In this case, [Nik] selected a pair of NEMA 17 steppers to do the job. They’re commanded by a NodeMCU ESP32, paired with TMC2209 stepper motor drivers. The carriage also includes a pen lifter, which relies on a MG90s servo to lift the drawing implement away from the wall.
The build is quite capable, able to recreate SVG vector graphics quite accurately, without obvious skew or distortion. [Nik] has been using the plotter with washable Crayola markers, so he can print on the wall time and again without leaving permanent marks. It’s a great way to decorate—over and over again—on a budget. Total estimated cost is under $100, according to [Nik].
The research paper with all the details is behind a paywall at this time, but we’ll summarize the important parts that are likely to get a hacker’s mind working.
Each fiber strand (like the one shown here) is a self-contained system. Multiple fibers can communicate with one another wirelessly to create a network that, when integrated into garments, performs tasks like health and activity monitoring while using very little power. And what’s really interesting about these fibers is their profound lack of anything truly exotic when it comes to their worky bits.
The inner components of a fiber computer are pretty recognizable: each contains a surface-mount microcontroller, LEDs, BLE (Bluetooth Low Energy) radio, light sensor, temperature sensor, accelerometer, and photoplethysmography (PPG) sensor for measuring blood volume changes through skin. Power is supplied by a separate segment containing a tiny cylindrical lithium-polymer battery, with a simple plug connector. It’s a tiny battery, but the system is so low-power that it still provides hours of operation.
If there’s a secret sauce, it’s in the fabrication. The first step is stretching a system into a long, thin circuit. Each component is nested onto a small piece of flex PCB that acts a little like a breakout board, and that flex PCB gets rolled around each component to make as tiny a package as possible. These little payloads are connected to one another by thin wires, evenly spaced to form a long circuit. That circuit gets (carefully!) sealed into a thermoformed soft polymer and given an overbraid, creating a fiber that has a few lumps here and there but is nevertheless remarkably thin and durable. The result can be woven into fabrics, worn, washed, bent, and in general treated like a piece of clothing.
Closeups of components that make up a single strand of “fiber computer”.
Multiple fibers are well-suited to being woven into clothing in a distributed way, such as one for each limb. Each fiber is self-contained but communicates with its neighbors using a BLE mesh, or transmitting data optically via embedded LEDs and light sensors. Right now, such a distributed system has been shown to be able to perform health monitoring and accurately classify different physical activities.
We’ve seen sensors directly on skin and transmitting power over skin, but this is a clever fusion of conventional parts and unconventional design — wearable computing that’s not just actually wearable and unobtrusive, but durable and even washable.
