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Quote Printer Keeps Receipts

January 3, 2026 by 9 Comments

In the world of social media, “keeping receipts” refers to the practice of storing evidence that may come in handy for a callout post at a later date. For [Teddy Warner], though, it’s more applicable to a little printer he whipped up to record the very best banter from his cadre of friends.

[Teddy’s] idea was simple. He hoped to capture amusing or interesting quotes his friends made in his apartment, and store them in a more permanent form. He also wanted to allow his friends to do the same. To that end, he whipped up a small locally-hosted web interface which his friends could use to record quotes, along with proper attribution. Hosted on a Raspberry Pi 5, the web interface can then truck those quotes out to an 80 mm thermal receipt printer. The anecdote, epithet, or witticism is then spat out with a timestamp in a format roughly approximating a receipt you might get from your local gas station. What’s neat is that [Teddy] was also able to install the entire system within the housing of the Miemieyo receipt printer, by 3D printing a custom base that could house the Pi and a suitable power supply.

Beyond being fun, this system also serves a critical purpose. It creates a paper trail, such that in-jokes, rumors, and insults alike can be traced back to their originating source. No more can Crazy Terry claim to have invented “the Malaga bit,” because the server and the receipt clearly log that Gerald dropped it first at the Boxing Day do.

We’ve seen similar projects before, too. There’s just something neat about holding a bit of paper in your hand.

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A giant pokeball is the best place to hide this holiday season.

Our New Years Wish Is To Hide In A Giant Pokéball

January 1, 2026 by 7 Comments

Between the news, the world situation, and the inevitable family stresses that come this time of year, well — one could be excused for feeling a certain amount of envy for those adorable pocket monsters who spend their time hidden away in red-and-white orbs. [carlos3dprint] evidently did, but he didn’t just dream of cozy concave solitude: he made it happen, with 3D printing and way too much post-processing.

Arguably 3D printing is not the ideal technique for such a large build, and even [carlos], despite the 3dprint in his handle, recognized this: the base frame of the sphere is CNC-routed plywood. He tried to use Styrofoam to make a skin, but evidently he’d lost access to the large CNC cutter he’d borrowed for the plywood frame at that point, as he was trying to do the cuts by hand. It still seems like it wouldn’t have be any worse than the little printed blocks from four different printers he eventually hot-stapled into a shell.

We only say that because based on his description of how much resin and filler went into creating a smooth outer surface on his Pokéball, the raw surface of the prints must have been pretty bad before fiberglass was applied. Still, it’s hard to argue with results, and the results are smooth, shiny and beautiful after all the sanding and painting. Could another technique have been easier? Maybe, but we hack with what we have, and [carlos] had 3D printers and knows how to make the best of them.

The interior of the ball is just large enough for a cozy little gaming nook, and no guesses what [carlos] is playing inside. The Instructable linked above doesn’t have many interior photos, though, so you’ll have to check the video (embedded below) for the interior fitting out, or jump to the tour at about the 15 minute mark.

Given ongoing concerns about VOCs from 3D printers, we kind of hope the Bulbsaur-themed printer he’s got in there is decorative, but it’s sure a nice homage to the construction method. Other pokeballs featured on Hackaday have been much smaller, but we’ve always had a soft spot for scaled-up projects.

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AI Picks Outfits With Abandon

December 17, 2025 by 4 Comments

Most of us choose our own outfits on a daily basis. [NeuroForge] decided that he’d instead offload this duty to artificial intelligence — perhaps more for the sake of a class project than outright fashion.

The concept involved first using an AI model to predict the weather. Those predictions would then be fed to a large language model (LLM), which would recommend an appropriate outfit for the conditions. The output from the LLM would be passed to a simple alarm clock which would wake [NeuroForge] and indicate what he should wear for the day. Amazon’s Chronos forecasting model was used for weather prediction based on past weather data, while Meta’s Llama3.1 LLM was used to make the clothing recommendations. [NeuroForge] notes that it was possible to set all this up to work without having to query external services once the historical weather data had been sourced.

While the AI choices often involved strange clashes and were not weather appropriate, [NeuroForge] nonetheless followed through and wore what he was told. This got tough when the outfit on a particularly cold day was a T-shirt and shorts, though the LLM did at least suggest a winter hat and gloves be part of the ensemble. Small wins, right?

We’ve seen machine learning systems applied to wardrobe-related tasks before. One wonders if a more advanced model could be trained to pick not just seasonally-appropriate clothes, but to also assemble actually fashionable outfits to boot. If you manage to whip that up, let us know on the tipsline. Bonus points if your ML system gets a gig on the reboot of America’s Next Top Model.

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Why Push A Button When A Machine Can Do It For You

December 16, 2025 by 21 Comments

Remote control is a wonder of the age, we press a button, and something happens as if by magic. But what happens if there is no remote control, and instead a real physical button must be pressed? [What Up TK Here], who regular Hackaday readers might just recognize, had just this problem, and made a remote control button presser.

It’s a 3D printed frame which we’re told is designed for a specific item, on top of which is mounted a hobby servo. Rotating the servo brings the lever down on the button, and the job is done. At the user end there’s a button in a printed enclosure that’s definitely not a knock-off of a well-known franchise from a notoriously litigious console company.

This is all good, but the interest for other projects lies in how it works. It’s using a pair of ESP32 microcontrollers, and instead of connecting to an existing WiFi network it’s using ESP-NOW for simplicity and low latency. This is a good application for the protocol, but as we’ve seen, it’s useful for a lot more than just button pressing.

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Condensing Diesel Heater Hack Is Dripping With Efficiency

December 13, 2025 by 13 Comments

Not a huge percentage of our readers probably get their heat from diesel fuel, but it’s not uncommon in remote areas where other fuels are hard to come-by. If you’re in one of those areas, this latest hack from [Hangin with the Hursts] could save you some change, or keep you  ̶2̶0̶%̶ ̶c̶o̶o̶l̶e̶r̶  25% warmer on the same fuel burn.

It’s bog simple: he takes his off-the-shelf hydronic diesel heater, which is already 71% efficient according to a previous test, and hooks its exhaust to a heat exchanger. Now, you don’t want to restrict the exhaust on one of these units, as that can mess with the air fuel mix, but [Hurst] gets around that with a 3″ intercooler meant for automotive intake. Sure, it’s not made for exhaust gas, but this is a clean-burning heater, and it wouldn’t be a hack if some of the parts weren’t out of spec.

Since it’s a hydronic heater, he’s able to use the exhaust gas to pre-heat the water going into the burner. The intercooler does a very good job of that, sucking enough heat out of the exhaust to turn this into a condensing furnace. That’s great for efficiency — he calculates 95%, a number so good he doesn’t trust it — but not so good for the longevity of the system, since this intercooler isn’t made to deal with the slightly-acidic condensation. The efficiency numbers are combustion efficiency, to be clear. He’s only accounting for the energy in the diesel fuel, not the energy that heats the water in his test, for the record; the electrical power going into the blower is considered free. That’s fair, since that’s how the numbers are calculated in the heating industry in general — the natural gas furnace keeping this author from freezing to death, for example, is a condensing unit that is also 95% efficient.

Another thing you can do to get the most from your diesel heating fuel is add some brains to the operation. Since this is a hydronic system, the cheapest option, long-term, might be to add some solar energy to the water. Sunlight is free, and diesel sure isn’t getting any cheaper.

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Get Statistical About Your Pet With This Cat Tracking Dashboard

December 13, 2025 by 3 Comments

Cats can be wonderful companions, but they can also be aloof and boring to hang out with. If you want to get a little more out of the relationship, consider obsessively tracking your cat’s basic statistics with this display from [Matthew Sylvester].

The build is based around the Seeedstudio ReTerminal E1001/E1002 devices—basically an e-paper display with a programmable ESP32-S3 built right in. It’s upon this display that you will see all kinds of feline statistics being logged and graphed. The data itself comes from smart litterboxes, with [Matthew] figuring out how to grab data on weight and litterbox usage via APIs. In particular, he’s got the system working with PetKit gear as well as the Whisker Litter Robot 4. His dashboard can separately track data for four cats and merely needs the right account details to start pulling in data from the relevant cat cloud service.

For [Matthew], the build wasn’t just a bit of fun—it also proved very useful. When one of his cats had a medical issue recently, he was quickly able to pick up that something was wrong and seek the help required. That’s a pretty great result for any homebrew project. It’s unrelated, too, but Gnocci is a great name for a cat, so hats off for that one.

We’ve featured some other fun cat-tracking projects over the years, too. If you’re whipping up your own neat hardware to commune with, entertain, or otherwise interact with your cat, don’t hesitate to let us know on the tipsline.

User Serviceable Parts

December 13, 2025 by 18 Comments

Al and I were talking on the podcast about the Home Assistant home automation hub software. In particular, about how devilishly well designed it is for extensibility. It’s designed to be added on to, and that makes all of the difference.
That doesn’t mean that it’s trivial to add your own wacky control or sensor elements to the system, but that it’s relatively straightforward, and that it accommodates you. If your use case isn’t already covered, there is probably good documentation available to help guide you in the right direction, and that’s all a hacker really needs. As evidence for why you might care, take the RTL-HAOS project that we covered this week, which adds nearly arbitrary software-defined radio functionality to your setup.

And contrast this with many commercial systems that are hard to hack on because they are instead focused on making sure that the least-common-denominator user is able to get stuff working without even reading a single page of documentation. They are so focused on making everything that’s in-scope easy that they spend no thought on expansion, or worse they actively prevent it.

Of course, it’s not trivial to make a system that’s both extremely flexible and relatively easy to use. We all know examples where the configuration of even the most basic cases is a nightmare simply because the designer wanted to accommodate everything. Somehow, Home Assistant has managed to walk the fine line in the middle, where it’s easy enough to use that you don’t have to be a wizard, but that you can make it do what you want if you are, and hence it got spontaneous hat-tips from both Al and myself. Food for thought if you’re working on a complex system that’s aimed at the DIY / hacker crowd.

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