Making A DIY Refrigerated Vest With Battery And Solar Power

February 7, 2026 by Maya Posch 1 Comment

Keeping a cool head is difficult at the best of times, least of all when it’s summer and merely thinking of touching bare skin to the pavement already gets you a second-degree burn. Unfortunately, it’s not possible to spend all summer in an air-conditioned room, but what if you took said room with you? Introducing [Hyperspace Pirate]’s air-conditioned vest.

Following on from last time’s adventures with a battery-powered air-conditioner that merely blew cold air onto one’s overheating body, this time the same compressor is used for a more compact build.

Since obviously using your body as part of the condenser would be uncomfortable, instead a heat exchanger was used that transfers the delicious frosty cold to water-filled tubing, zip-tied inside a very fashionable vest.

The basic unit runs on a couple of LiPo packs, but a solar-powered circuit was also built and tested using two small-ish panels. Of course, the requisite backpack-sized setup for that configuration is somewhat bulky, but at least the panels can also provide shade in addition to power for the compressor, hitting two fiery birds with one frosty stone.

Compared to one of those solar-powered caps with a built-in fan, this unit with some refinement could actually be an improvement, as well as keeping you a lot chillier. We’re looking forward to [Hyperspace]’s trial runs in the upcoming Floridian summer, as well as future chilling adventures.

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A biohacker with her lactose-rich slurry

Biohack Your Way To Lactose Tolerance (Through Suffering)

December 13, 2025 by Tyler August 49 Comments

A significant fraction of people can’t handle lactose, like [HGModernism]. Rather than accept a cruel, ice cream free existence, she decided to do something you really shouldn’t try: biohacking her way to lactose tolerance.

The hack is very simple, and based on a peer reviewed study from the 1990s: consume lactose constantly, and suffer constantly, until… well, you can tolerate lactose. If you’re lactose intolerant, you’re probably horrified at the implications of the words “suffer constantly” in a way that those milk-digesting-weirdos could never understand. They probably think it is hyperbole; it is not. On the plus side, [HGModernism]’s symptoms began to decline after only one week.

The study dates back to the 1980s, and discusses a curious phenomenon where American powdered milk was cluelessly distributed during an African famine. Initially that did more harm than good, but after a few weeks mainlining the white stuff, the lactose-intolerant Africans stopped bellyaching about their bellyaches.

Humans all start out with a working lactase gene for the sake of breastfeeding, but in most it turns off naturally in childhood. It’s speculated that rather than some epigenetic change turning the gene for lactose tolerance back on — which probably is not possible outside actual genetic engineering — the gut biome of the affected individuals shifted to digest lactose painlessly on behalf of the human hosts. [HGModernism] found this worked but it took two weeks of chugging a slurry of powdered milk and electrolyte, formulated to avoid dehydration due to the obvious source of fluid loss. After the two weeks, lactose tolerance was achieved.

Should you try this? Almost certainly not. [HGModernism] doesn’t recommend it, and neither do we. Still, we respect the heck out any human willing to hack the way out of the limitations of their own genetics. Speaking of, at least one hacker did try genetically engineering themselves to skip the suffering involved in this process. Gene hacking isn’t just for ice-cream sundaes; when applied by real medical professionals, it can save lives.

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Reason Versus Sentimental Attachment For Old Projects

December 5, 2025 by Maya Posch 31 Comments

We have probably all been there: digging through boxes full of old boards for projects and related parts. Often it’s not because we’re interested in the contents of said box, but because we found ourselves wondering why in the name of project management we have so many boxes of various descriptions kicking about. This is the topic of [Joe Barnard]’s recent video on his BPS.shorts YouTube channel, as he goes through box after box of stuff.

For some of the ‘trash’ the answer is pretty simple; such as the old rocket that’s not too complex and can have its electronics removed and the basic tube tossed, which at least will reduce the volume of ‘stuff’. Then there are the boxes with old projects, each of which are tangible reminders of milestones, setbacks, friendships, and so on. Sentimental stuff, basically.

Some rules exist for safety that make at least one part obvious, and that is that every single Li-ion battery gets removed when it’s not in use, with said battery stored in its own fire-resistant box. That then still leaves box after box full of parts and components that were ordered for projects once, but not fully used up. Do you keep all of it, just in case it will be needed again Some Day™? The same issue with boxes full of expensive cut-off cable, rare and less rare connectors, etc.

One escape clause is of course that you can always sell things rather than just tossing it, assuming it’s valuable enough. In the case of [Joe] many have watched his videos and would love to own a piece of said history, but this is not an option open to most. Leaving the question of whether gritting one’s teeth and simply tossing the ‘value-less’ sentimental stuff and cheap components is the way to go.

Although there is always the option of renting storage somewhere, this feels like a cheat, and will likely only result in the volume of ‘stuff’ expanding to fill the void. Ultimately [Joe] is basically begging his viewers to help him to solve this conundrum, even as many of them and our own captive audience are likely struggling with a similar problem. Where is the path to enlightenment here?

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A hand holds a charcoal-colored rectangle with a black and white screen in taking up most of its face. A bulleted list of items are displayed: "Start work on new blog, Update eSticky FW, Start working on eSticky PCB, New enclosure for eSticky, Buy 18650 battery, Buy 3DP extruder anycubic, FW Update Sigma 18-35."

ESticky Is A Paperless Post-It

August 23, 2025 by Navarre Bartz 21 Comments

E-paper screens have opened up a wide variety of novel use cases that just wouldn’t work with the higher power draw of an LCD. [gokux] thought it would be perfect for a digital sticky note.

Using a Waveshare 2.9″ e-paper display hooked up to a Seeed Studio XIAO ESP32C3, a battery, and a switch all inside the 3D printed enclosure, the part count on this is about as simple as it gets. Once everything is soldered together and programmed, you get a nifty little display that can hold some of your thoughts without having to reopen an app to get to them.

Access is currently provided via a web page, and there are a few minor hiccups like text alignment and image upload support. This project is open source, so [gokux] has expressed interest in anyone wanting to help refine the concept. We think it might be nice to add a magnet on the back for an easier way to actually stick to things.

If you prefer a different way to use electricity for a sticky note, why not do it at 2,000 V? If that’s not your jam, how about a plotter that writes your label or message on masking tape?

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Can A Thermal Printer Cure ADHD?

August 6, 2025 by Tyler August 34 Comments

No, of course not. Per Betteridge’s law, that’s the answer to any headline with a question mark. On the other hand, while a thermal printer might not cure ADHD, it can help treat it — according to [Laurie Hérault], to the point of curing his procrastination habit. Even if you don’t have ADHD, you probably do procrastinate sometimes, so this hack is worth a look.

The printer itself is a key hardware portion of the hack, but the hack itself is purely organizational. [Laurie] started with post-its before adding automation. Before the post-it notes came a simple realization: [Laurie] could sit and play games for hours, but not buckle down for serious work for more than a few minutes, if he could even get started. (Who can’t relate?) That sent him down a rabbit hole reading about the psychology of what makes games so addictive — and the idea of “gamification” that was so popular in educational circles not long ago.

Unlike work, games give you a loop of unambiguous, instant, and continuous feedback to pump your dopamine circuits. [Laurie] uses the example of an FPS. You aim, you shoot — and either you miss, or you hit the target. Either way, there’s feedback. When you hit, your brain gives you dopamine. This fast loop of input -> feedback is what [Laurie] felt he was missing from his day.

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Prusa Mini with endoscope nozzle cam and pip preview

Prusa Mini Nozzle Cam On The Cheap

May 2, 2025 by Heidi Ulrich 2 Comments

Let me throw in a curveball—watching your 3D print fail in real-time is so much more satisfying when you have a crisp, up-close view of the nozzle drama. That’s exactly what [Mellow Labs] delivers in his latest DIY video: transforming a generic HD endoscope camera into a purpose-built nozzle cam for the Prusa Mini. The hack blends absurd simplicity with delightful nerdy precision, and comes with a full walkthrough, a printable mount, and just enough bad advice to make it interesting. It’s a must-see for any maker who enjoys solder fumes with their spaghetti monsters.

What makes this build uniquely brilliant is the repurposing of a common USB endoscope camera—a tool normally reserved for inspecting pipes or internal combustion engines. Instead, it’s now spying on molten plastic. The camera gets ripped from its aluminium tomb, upgraded with custom-salvaged LEDs (harvested straight from a dismembered bulb), then wrapped in makeshift heat-shrink and mounted on a custom PETG bracket. [Mellow Labs] even micro-solders in a custom connector just so the camera can be detached post-print. The mount is parametric, thanks to a community contribution.

This is exactly the sort of hacking to love—clever, scrappy, informative, and full of personality. For the tinkerers among us who like their camera mounts hot and their resistor math hotter, this build is a weekend well spent.

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An ESP32 Pomodoro Timer

March 29, 2025 by Jenny List 15 Comments

The Pomdoro technique of time management has moved on a little from the tomato-shaped kitchen timer which gave it a name, as [Rukenshia] shows us with this nifty ESP32 and e-paper design. It’s relatively simple in hardware terms, being a collection of off-the-shelf modules in a 3D printed case, but the software has a custom interface for the friend it was built for.

At its heart is a NodeMCU board and a Waveshare display module, with a rotary encoder and addressable LED as further interface components. A lot of attention has been paid to the different options for the interface, and to make the front end displayed on the screen as friendly and useful as possible. Power comes via USB-C, something that should be available in most working environments here in 2025.

We’ve tried a variant on this technique for a while now with varying success, maybe because a mobile phone doesn’t make for as good a timer as a dedicated piece of hardware such as this. Perhaps we should follow this example. If we did, the Hackaday timer couldn’t possibly use an ESP32.