Hacking A Reverse Osmosis Water Filter Through Its Smart Faucet

June 30, 2026 by 3 Comments

Reverse-osmosis (RO) systems are one way to ensure that you get very clean drinking water. The Waterdrop G3P600 variety that [Tomasz Wasilczyk] recently purchased is definitely among the fanciest and ‘smartest’, with the faucet having its own 7-segment display and gaggle of LEDs connected to the actual RO unit with a four-pin connector. This naturally meant that whatever protocol runs on this cable had to be reverse-engineered for science.

Now with more custom PCB. (Credit: Tomasz Wasilczyk)
Now with more custom PCB.

The main practical benefit here is to make the system smarter — such as plugging it into a home automation system with ESPHome support, as well as make it play nice with refrigerator lines.

What automation and monitoring options exist here thus depend on what data gets sent between the RO unit and the faucet. Fortunately this turned out to be quite extensive, ranging from filter health, the water quality and pump status as well as air temperature and faucet state.

Unsurprisingly the four-pin connector turned out to be a basic serial link, with 5 V, ground and a 9,600 baud connection. From this it was easy enough to deduce the protocol, and by looking at what lit up on the faucet, a custom PCB wasn’t far behind.

After one blown-up fuse later due to getting 24 V instead of 12 V on the RO unit when tapping off power, the unit popped to life and was able to be connected to Home Assistant, from where the entire functionality and what triggered what could be mapped out. Of course, there’s still more to be discovered and reverse-engineered in the unit, but this seems like a good place to start.

Web Tool Lets You Take Steam Controller For A Drive

June 30, 2026 by 3 Comments

One of the simplest robots to make is a bristlebot — a motor with an offset weight is attached to the head of a toothbrush, and the resulting vibrations will move the contraption across a flat surface. [Very Lazy Pixels] recently took this idea a bit further by turning the Steam Controller into a steerable, bristlebot-like robot.

To drive one’s Steam Controller across a desk, all that is needed is for a computer with a paired controller and a Chromium-based browser. From there, using the WASD buttons, the web interface converts traditional video game inputs into controller motion by spinning the controller’s rumble motors at a specific frequency. With precise control of these motors, the controller can move forwards and backwards and even turn, which is a great deal more advanced than the traditional bristlebots generally manage.

Part of what makes this possible is Valve’s willingness to release information about many of their products to the general public, enabling anyone to modify or upgrade those products to their liking. While not completely open source, it’s a step in the right direction and enables fun projects like these. We’ve seen other Valve products turned into surprisingly barebones single-board computers as well as custom portable workstations thanks to this philosophy.

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Making A Magnetic Core Memory USB Drive

June 29, 2026 by 3 Comments

Some of us have felt somewhat nervous about the collapse of DRAM and NAND Flash memory supply in the consumer market, while others seem to have fully embraced it. Someone like [polymatt] for example, whose recent project entails a USB drive that skips back quite a few decades and opts to use a glorious 64-bit core memory device for storage.

To really embrace the DIY spirit here, the PCBs were milled using a small CNC router before the core memory was assembled alongside the other components, including apparently L293 H-bridge ICs as the drivers, along with an ESP32 module for the brains and USB interface.

Core memory relies on sensing the state of a cell through a destructive read action, which thus requires a fair bit of surrounding logic to set up read and writes, parse sense line values and restore any read value after said destructive read. Determining the right voltage to use during read and write actions is essential, and here determined experimentally.

The final build contains two PCBs inside an enclosure that’s filled with silicone oil. Other than looking cool through the acrylic window, it also helps to keep the individual cores at a fairly consistent temperature, which is helpful with reliable bit flipping, even if it’s probably overkill here.

Ignoring for a moment that just the memory required for the USB stack in the ESP32 module is many times the size of this core memory device, it’s still a very cool project whose appeal goes far beyond mere practicality.

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The Terrifying 2011-Era Case Of Max Planck’s Retracted Papers

June 29, 2026 by 5 Comments

In the world of scientific publishing there are many reasons why a paper can be retracted, but generally there is an obvious and clearly communicated reason for doing so. Thus when [Yves Gingras] – a historian of physics – and [Mahdi Khelfaoui] – a colleague – noticed recently that two 1940s papers by [Max Planck] had been quite recently retracted, this resulted in an eyebrow-raising double-take, before naturally publishing their investigation’s findings on arXiv.

They first became aware of this courtesy of the site Retraction Watch and their list of ‘Retractions by Nobel Prize winners‘, which had the authors do a spit-take when they saw [Max Planck] listed. This page led them to a total of two database entries, as listed above. One is for a 1940 paper, the other for a 1942 paper, only five years before [Planck]’s death.

As for the provided reasons, both articles were struck with a generic ‘copyright violation’, which at the very least seems somewhat puzzling, and started both authors of this recent investigation on their journey. What they found was less of a nefarious plot and more of an accidental black hole that had formed when scientific journals began to digitize papers.

The original journal that [Planck]’s papers were published in was absorbed like so many into Springer Nature, where an automated system then tried to sort through all the papers, including the usual detecting of copyright issues. With these papers predating the era of convenient DOIs and the more standard forms of citing related works, said automated system appears to have become rather confused and hurt these papers in its confusion.

From the side of Springer Nature there has so far been no commentary on this, and as of writing the original papers are still listed as withdrawn. Although one can still read the original scanned papers via the Internet Archive, such as here the 1940 paper, it’s disturbing to see that automated systems have apparently been let loose on these veritable archives of scientific and academic history, heedless of the damage inflicted along the way.

Although after fifteen years these two retractions were finally noticed, the more harrowing question is probably just how many papers from potentially less well-known authors were quietly scuttled. If this can happen to [Planck]’s works, it would appear that nobody is safe, including legends like [Bohr], [Einstein] and so many others.

Hard Drive Speakers Crank Out Classic Demo

June 29, 2026 by 3 Comments

Second Reality is a legendary demoscene release by Future Crew, which won Assembly 1993 with its technical and artistic mastery. [Niv Singer] decided to give the classic demo a spin on a rather unconventional sound system with a particuarly techy twist.

Hard drives are great for storing data. They’re designed for this purpose. What they’re not designed for is acting as speakers, but you can hack them into acting that way if you’re so inclined. For this project, [Niv] pulled apart a whole stack of drives, so they could be repurposed in this way. The principle is simple enough—just feed audio to the coil driving the head, and it will vibrate and wiggle around, creating soundwaves in the air. It’s not particularly effective, and you get limited volume with a terrible frequency response, but that’s half the fun. [Niv] actually took some of this into account, too. Four Western Digital Caviar 500GB drives were chosen for this build, two for the left channel, and two for the right. Each channel had a crossover, allowing one drive to handle low frequencies while the other handled higher ones. For a further nice touch, the platters spin with the beat as well, with [Niv] providing a great explanation on how this was achieved with the use of some nifty PWM tricks.

Files are on Github for the curious. We’ve featured plenty of hard drive speakers before, too. Video after the break.

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Piano Escapement Migrates To Drum Kit

June 29, 2026 by 2 Comments

For as popular as the piano is in music studios, homes, and schools, it almost defies logic. Compared to a guitar, harmonica, or drum set, pianos are incredibly complex machines that can have somewhere on the order of 8,000 moving parts in a case that can easily weigh hundreds of pounds and which often responds quite poorly to seasonal changes in temperature and humidity. But for putting up with all of these downsides, musicians are rewarded with an instrument that uniquely responds to touch, style, and emotion. A big reason for that is that mechanical complexity, and [Super Valid Designs] is attempting to bring that design to a drum set.

Compared to the complex machinery that connects the movement of a piano’s key to its hammer striking a string, a kick drum pedal is much simpler. It can only bounce off of the drum or get “buried” where the beater remains pressed up against the drum after hitting it. [Super Valid Designs] wanted something with a bit more finesse and control, so he first 3D printed a mechanism that throws the beater towards the drum head and then disconnects it mechanically from the pedal, so that it rebounds even if the pedal stays depressed. The next steps were more difficult, which involved making sure the mechanism reset itself in a repeatable way, without making too much noise of its own. This involved trying out a few different ideas and printing a massive amount of subtly different linkages, but in the end he’s left with a machine that nearly replicates all of the parts of a piano’s escapement,

The end goal of this project wasn’t simply to reproduce piano mechanisms on a drum set, though. [Super Valid Designs] hopes to make a kick drum that’s much smaller than those found in traditional kits, and since smaller drums respond poorly when the beater remains on or near the drum after striking it, a mechanism like this will dramatically improve the performance of the smaller drum and help reduce the requirement for perfect technique. And, maybe in 50 years or so, these types of escapements will take over the drumming world just like the piano escapement took over keyboards after its invention in the 1700s. Some simpler piano actions have been built before, but the complexity seems to be a requirement for all of the tasks they need to do whether its for a piano or a drum.

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2026 Frikkin Lasers Challenge: Super-Simple Laser Precision For Your Stargazing

June 29, 2026 by 8 Comments

Perhaps the hardest thing for amateur astronomers just starting out is finding the things you want to look at. Prolific maker [mircemk] has submitted a quick-and-easy star-hopper device that will help guide your binoculars with laser-like precision using things you likely already have on hand: a smartphone, a mounting plate, and a green laser pointer.

The smartphone is running AstroHopper, an astronomy app that uses GPS and inertial navigation to know exactly where your phone is pointing, and offer an image of the sky on the screen. There are many others of this ilk, and there’s no reason [mircemk]’s trick won’t work with your favorite. The trick is decidedly simple: the smartphone is mounted to a flat plate, in line with a green laser pointer. Careful placement aligns the axis of the phone and the laser, and the mounting plate is set up to fit a tripod.

Using it is simple: with a labelled view of the sky displayed on the screen, one lines up the phone/laser combo with the desired object, and activates the laser pointer. [micremk] has wired in an on-off switch for this purpose and a large external battery, rather than relying on the stock pushbutton. Since the axis of the laser pointer and the phone are aligned, a green line launches out into the heavens for you to follow with your binoculars. Once you locate that green dot, you can turn off the laser. Yes, the computer has helped you find the object, but your muscles are doing the slewing and that will make it much more likely you start to learn the sky yourself rather than relying on electronic magic.

This is probably the simplest hack we’ve yet seen in the Frikkin’ Lasers Challenge, and yet also one of the most practical. If you enjoy playing with radiation that’s spontaneously emitted, there’s still time to get your entry together — the contest runs until July 23, 2026.

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