2026-05-02 10:00:08
The solar system is kind of hard to observe in motion all at once. Sometimes, it’s nice to have a little model to look at, so you can see the relative motions of celestial bodies play out in front of you. Such a device is called an orrery, and [illusionmanager] has built rather a nice example of their own.
The build represents all the planets in the solar system, plus the sun and our very own Moon. An ESP32 lives at the heart of the build, running an astronomical simulation to calculate the proper positions of all the celestial objects. It then drives a small stepper motor via a TMC2209 driver, turning the mechanism back and forth until all the pieces are positioned correctly, using a reed switch and magnet to detect the initial zero position. The orrery is able to be driven by a single motor in this manner thanks to an ingenious mechanism, wherein the rings interlock with each other when turned in one direction, and not in the other. The Moon is controlled by a separate geared mechanism connected to the main rotation.
It’ s a nice decoration that also serves as a great conversation piece, particularly if you like talking about the heavens. We’ve featured some fine works from [illusionmanager] before, too, like this exquisite reverse sundial. Video after the break.
2026-05-02 07:00:01
Producing hot water off-grid is a surprisingly energy-intensive activity, and although it looks simple on its surface it can get quite complicated especially when used in large scale for something like providing hot water for an entire home. When using combustion to heat the water there needs to be proper venting as well as control of the fuel, and even storage of the hot water needs to be meticulous to avoid certain pathogens. [Greenhill Forge] has built an off-grid solution for heating hot water that doesn’t necessarily rely on any combustion, though, provided he can find something to spin his custom electric machine.
The machine in question is, of course, an induction heater. It works similar to any simple electric motor, generator, or transformer except in this case the eddy currents generated are exploited rather than minimized. Normally these currents, generated when a magnet passes by a metal, are wasted heat in other machines but in this induction heater it’s the goal. The machine’s stator is built from copper tube wound in a spiral which allows water to flow through and absorb heat. The tube is soldered into one electrically solid mass to maximize the eddy currents. The rotor is taken from a previous generator built by [Greenhill Forge] which holds the permanent magnets.
During the initial tests using a power drill to drive the generator, he was able to heat 1.5 liters of water from 7.9C to about 24.4 C in three minutes. The math works out to providing 575 watts of power to the heater, and with something that could spin the generator faster it might have the potential to provide around 14.5 kW. Provided that there’s a source of energy around, such as a wind or water turbine, this could be a fairly sustainable way of generating hot water in off-grid situations. Some of [Greenhill Forge]’s other projects are centered around this idea as well, like one of his builds which uses waste sawdust to heat his workshop with a custom-built stove.
2026-05-02 04:00:32
You can get all kinds of fancy lenses for modern cameras, with all sorts of mechanical and electronic wizardly to make them shoot better images. But what if you paired a vintage lens with a modern camera? It would take some work, as [Mathieu] found out, but you’d also get some interesting results.
The optic in question is a 100-year old lens—a Foth 50 mm f2.5 to be precise, originally used with a folding film camera. It was sourced from a market for just 3 euros. Notably, the lens was not designed for modern cameras, and so lacks an aperture and focusing mechanism. [Mathieu] thus had to fabricate something to fit the lens to a Sony FX3. A first attempt used an aperture adapter from Amazon and an elcoid adapter, but there were vignetting problems due to the lens placement in this case. Ultimately, [Mathieu] went with a special macro adapter that allowed him to control focus and tuck in an ND filter behind the lens, which made up for the lack of an aperture.
The vintage glass isn’t the sharpest lens out there, but that’s kind of what’s fantastic about it. The center of the frame is certainly focused, but it fades out softly towards the edges of the image, giving a cinematic, dreamlike effect. The bokeh in the background are particularly charming, too. As far as 3 euro lenses go, this one was a hit.
You can slap just about any lens on anything if you get creative with how you do it. Video after the break.
[Thanks to Stephen Walters for the tip!]
2026-05-02 02:30:54
Continuing his quest to put DOOM on literally everything that has a capable enough processor and a screen, [Aaron Christophel]’s most recent target is a Slate 7 Pro travel router. With a generous 2.8″ touch screen and a lot of onboard processing power to handle all the advertised networking and routing features via its WAN and (W)LAN interfaces, it should be able to run the game really quite well. As usual the main question is how to get the game to run on it first.
The port of choice is fbdoom, with instructions on how to run it on this router provided on the GitHub project page. The reason for the touch screen is so that you can see the status of interfaces and interact with it without having to open the web interface. Boringly, this router has an SSH daemon ready to connect to, giving you full root access to the Linux-based firmware.
It’s just your typical AArch64 ARM-based system, with the gl_screen process running for the touch screen display. From there it was easy enough to deduce the settings to jot into fbdoom so that it too could use the same screen and touch inputs. After copying the compiled binary with SCP over to the router, it can then be started like any application. With touch inputs somewhat awkwardly mapped to certain areas of the touch screen, it’d be nice to see the USB 2.0 port used for USB HID inputs, but it does show how easy things can be when it runs something like Linux and you got full root access.
Incidentally this also heavily blurs the lines between something like a Valve Steamdeck and a router, with the latter just missing some gamepad controls on the side to do some on-the-go gaming when you’re not using it for routing network traffic.
2026-05-02 00:00:16
This week, Hackaday’s Elliot Williams and Kristina Panos met up over the international tubes to bring you the latest news, mystery sound results show, and of course, a big bunch of hacks from the previous seven days or so.
Regarding Hackaday Europe, we announced the last round of speakers and opened up the workshop ticket sales. In other news, the Green-Powered Challenge has wrapped, and judging will begin quite soon.
On What’s That Sound, we can score another one for Kristina, which brings her record to approximately four wins and sixty-eight losses. She knew without a doubt that this was a guillotine paper cutter, probably because she recorded the sound herself. Hey, don’t take this away from her.
After that, it’s on to the hacks, beginning with a really cool laser-powered mist-and-mirrors multi-view display, a robotic drawing assistant of questionable utility, and a new slicer that enables horizontal overhangs without supports.
We also look at a trackball 3D controller, a 3D-printed pinball machine, and a good way to kill humidity sensors with humidity. Finally, we’re both shocked to learn that we’ve been on GPS mk. II for some time now. But then once we get over that, we talk tablets and their usefulness, or lack thereof.
Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!
Download in DRM-free MP3 and savor at your leisure.
2026-05-01 23:30:30
Phones can be distracting objects if you’re not an enlightened master of the mental arts. Even just reading an email or glancing at your calendar can get you caught up checking other apps and notifications and waste your time. [Paul Lagier] built a device to eliminate this problem by showing him critical information right on his desk.
The device is based around an off-the-shelf Waveshare ESP32 board which packs in a small 8×8 RGB LED matrix on one side. It’s a neat way to get an LED project up and running quickly, but [Paul] noted that it didn’t look that great out of the box. He had to experiment with some different solutions for diffusing the light, eventually wrapping the board in a 3D printed housing with a black grid to separate the light output from each LED to make a clear pixelated display.
The ESP32’s wireless connectivity comes in handy, because it’s able to query web services for [Paul’s] calendar and other useful data. The user interface is minimal—you merely flip the housing into a different orientation to display different information, relying on the onboard QMI8658 6-axis sensor. The main display shows [Paul’s] calendar in 15 minute blocks so he can keep track of meetings without having to open his phone. Shaking the device in this mode will display the events as scrolling text. There’s also an ambient mode that looks pretty, and a pairing mode for setting up the wireless connectivity.
The great thing about modern electronic hardware is that it’s very easy to produce productivity aids like this to suit your own lifestyle.
