Charge NiMH Batteries With Style, Panache And An RP2040

November 19, 2025 by 1 Comment

The increasing dominance of lithium cells in the market place leave our trusty NiMH cells in a rough spot. Sure, you can still get a chargers for the AAs in your life, but it’s old tech and not particularly stylish. That’s where [Maximilian Kern] comes in, whose SPINC project was recently featured in IEEE Spectrum— so you know it has to be good.

With the high-resolution LED, the styling of this device reminds us a little bit of the Pi-Mac-Nano— and anything that makes you think of a classic Macintosh gets automatic style points. There’s something reminiscent of an ammunition clip in the way batteries are fed into the top and let out the bottom of the machine.

[Maximilian] thought of the, ah, less-detail-oriented amongst us with this one, as the dedicated charging IC he chose (why reinvent the wheel?) is connected to an H-bridge to allow the charger to be agnostic as to orientation. That’s a nice touch. An internal servo grabs each battery in turn to stick into the charging circuit, and deposits it into the bottom of the device once it is charged. The LCD screen lets you monitor the status of the battery as it charges, while doubling as a handy desk clock (that’s where the RP2040 comes in). It is, of course, powered by USB-C-PD as all things are these days. Fast-charging upto 1A is enabled, but you might want to go slower to keep your cells lasting as long as possible. Firmware, gerbers and STLs are available on GitHub under a GPL-3.0 license– so if you’re still using NiCads or want to bring this design into the glorious lithium future, you can consider yourself welcome to.

We recently featured a AA rundown, and for now, it looks like NiMH is still the best bang for your buck, which means this project will remain relevant for a few years yet. Of course, we didn’t expect the IEEE to steer us wrong.

Thanks to [George Graves] for the tip.

Hacking A Pill Camera

November 18, 2025 by 4 Comments

A gastroscopy is a procedure that, in simple terms, involves sticking a long, flexible tube down a patient’s throat to inspect the oesophagus and adjacent structures with a camera fitted to the tip. However, modern technology has developed an alternative, in the form of a camera fitted inside a pill. [Aaron Christophel] recently came across one of these devices, and decided to investigate its functionality.

[Aaron’s] first video involves a simple teardown of the camera. The small plastic pill is a marvel of miniaturization. Through the hemispherical transparent lens, we can see a tiny camera and LEDs to provide light in the depths of the human body. Slicing the camera open reveals the hardware inside, however, like the miniature battery, the microcontroller, and the radio hardware that transmits signals outside the body. Unsurprisingly, it’s difficult to get into, since it’s heavily sealed to ensure the human body doesn’t accidentally digest the electronics inside.

Unwilling to stop there, [Aaron] pushed onward—with his second video focusing on reverse engineering. With a little glitching, he was able to dump the firmware from the TI CC1310 microcontroller. From there, he was able to get to the point where he could pull a shaky video feed transmitted from the camera itself. Artists are already making music videos on Ring doorbells; perhaps this is just the the next step.

Smart pills were once the realm of science fiction, but they’re an increasingly common tool in modern medicine. Video after the break.

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Kubernetes Cluster Goes Mobile In Pet Carrier

November 18, 2025 by 1 Comment

There’s been a bit of a virtualization revolution going on for the last decade or so, where tools like Docker and LXC have made it possible to quickly deploy server applications without worrying much about dependency issues. Of course as these tools got adopted we needed more tools to scale them easily. Enter Kubernetes, a container orchestration platform that normally herds fleets of microservices in sprawling cloud architectures, but it turns out it’s perfectly happy running on a tiny computer stuffed in a cat carrier.

This was a build for the recent Kubecon in Atlanta, and the project’s creator [Justin] wanted it to have an AI angle to it since the core compute in the backpack is an NVIDIA DGX Spark. When someone scans the QR code, the backpack takes a picture and then runs it through a two-node cluster on the Spark running a local AI model that stylizes the picture and sends it back to the user. Only the AI workload runs on the Spark; [Justin] also is using a LattePanda to handle most of everything else rather than host everything on the Spark.

To get power for the mobile cluster [Justin] is using a small power bank, and with that it gets around three hours of use before it needs to be recharged. Originally it was planned to work on the WiFi at the conference as well but this was unreliable and he switched to using a USB tether to his phone. It was a big hit with the conference goers though, with people using it around every ten minutes while he had it on his back. Of course you don’t need a fancy NVIDIA product to run a portable kubernetes cluster. You can always use a few old phones to run one as well.

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Humane Mousetrap Lets You Know It’s Caught Something

November 18, 2025 by 15 Comments

“Build a better mousetrap and the world will beat a path to your door,” so goes the saying, but VHS beat Betamax and the world hasn’t been the same since. In any case, you might not get rich building a better mousetrap, but you can certainly create something more humane than the ol’ spring’n’snap, as [nightcustard] demonstrates.

The concept is the same as many humane mousetraps on the market. The mouse is lured into a confined cavity with the use of bait, and once inside, a door closes to keep the mouse inside without injuring it. [nightcustard] achieved this by building a plastic enclosure with plenty of air holes, which is fitted with a spring-loaded door. When a mouse walks through an infra-red break beam sensor, a Raspberry Pi Pico W triggers a solenoid which releases the door, trapping the mouse inside. This design was chosen over a passive mechanical solution, because [nightcustard] noted that mice in the attic were avoiding other humane traps with obvious mechanical trigger mechanisms.

As a bonus, the wireless connectivity of the Pi Pico W allows the trap to send a notification via email when it has fired. Thus, you can wake up in the morning and check your emails to see if you need to go and release a poor beleaguered mouse back into the wild. This is critical, as otherwise, if you forget to check your humane trap… it stops being humane pretty quickly.

If you’re looking for more inspiration to tackle your mouse problems, we can help. We’ve featured other traps of this type before, too. Meanwhile, if you’ve got your own friendly homebrew solutions to pesky pest problems, don’t hesitate to hit up the tipsline.

Casting Metal Tools With Kitchen Appliances

November 18, 2025 by 14 Comments

Perhaps the biggest hurdle to starting a home blacksmithing operating is the forge. There’s really no way around having a forge; somehow the metal has to get hot enough to work. Although we might be imagining huge charcoal- or gas-fired monstrosities, [Shake the Future] has figured out how to use an unmodified, standard microwave oven to get iron hot enough to melt and is using it in his latest video to cast real, working tools with it.

In the past, [Shake the Future] has made a few other things with this setup like an aluminum pencil with a graphite core. This time, though, he’s stepping up the complexity a bit with a working tool. He’s decided to build a miniature bench vice, which uses a screw to move the jaws. He didn’t cast the screw, instead using a standard size screw and nut, but did cast the two other parts of the vice. He first 3D prints the parts in order to make a mold that will withstand the high temperatures of the molten metal. With the mold made he can heat up the iron in the microwave and then pour it, and then with some finish work he has a working tool on his hands.

A microwave isn’t the only kitchen appliance [Shake the Future] has repurposed for his small metalworking shop. He also uses a standard air fryer in order to dry parts quickly. He works almost entirely from the balcony of his apartment so he needs to keep his neighbors in mind while working, and occasionally goes to a nearby parking garage when he has to do something noisy. It’s impressive to see what can be built in such a small space, though. For some of his other work be sure to check out how he makes the crucibles meant for his microwave.

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Cheap VHF Antenna? Can Do!

November 18, 2025 by 2 Comments

The magnetic loop antenna is a familiar sight in radio amateur circles as a means to pack a high performance HF antenna into a small space. It takes the form of a large single-turn coil made into a tuned circuit with a variable capacitor, and it provides the benefits of good directionality and narrow bandwidth at the cost of some scary RF voltages and the need for constant retuning. As [VK3YE] shows us though, magnetic loops are not limited to HF — he’s made a compact VHF magnetic loop using a tin can.

It’s a pretty simple design; a section from the can it cut out and made into a C shape, with a small variable capacitor at the gap. The feed comes in at the bottom, with the feed point about 20 % of the way round the loop for matching. The bandwidth is about 100 MHz starting from the bottom of the FM broadcast band, and he shows us it receiving broadcast, Airband, and 2 meter signals. It can be used for transmitting too and we see it on 2 meter WSPR, but we would have to wonder whether the voltages induced by higher power levels might be a little much for that small capacitor.

He’s at pains to point out that there are many better VHF antennas as this one has no gain to speak of, but we can see a place for it. It’s tiny, if you’re prepared to fiddle with the tuning its high Q gets rid of interference, and its strong side null means it can also reduce unwanted signals on the same frequency. We rather like it, and we hope you will too after watching the video below.

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Congratulations To The 2025 Component Abuse Challenge Winners

November 18, 2025 by 5 Comments

For the Component Abuse Challenge, we asked you to do the wrong thing with electrical parts, but nonetheless come out with the right result. It’s probably the most Hackaday challenge we have run in a long time, and you all delivered! The judging was tight, but in the end three projects rose up to the top, and will each be taking home a $150 DigiKey gift certificate, but that doesn’t mean you shouldn’t give all of the projects a look.

So without further ado, let’s check out the winners and all the others that tickled the hacky regions of our judges’ brains. Continue reading “Congratulations To The 2025 Component Abuse Challenge Winners” →