Hackaday Columns

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This excellent content from the Hackaday writing crew highlights recurring topics and popular series like Linux-Fu, 3D-Printering, Hackaday Links, This Week in Security, Inputs of Interest, Profiles in Science, Retrotechtacular, Ask Hackaday, Teardowns, Reviews, and many more.

Get Your Green Power On!

March 3, 2026 by 2 Comments

Nobody likes power cords, and batteries always need recharging or replacing. What if your device could run on only the power it could gather together by itself from the world around it? It would be almost like free energy, although without breaking the laws of physics.

Hackaday’s 2026 Green-Powered Challenge asks you to show us your devices, contraptions, and hacks that can run on the power they can harvest. Whether it’s heat, light, vibration, or any other source of energy that your device gathers to keep running, we’d like to see it.

The top three entries will receive $150 shopping sprees courtesy of the contest’s sponsor, DigiKey, so get your entry in before April 24, 2026, to be eligible to win.

Honorable Mentions

As always, we have several honorable mention categories to get your creative juices flowing:

  • Solar: In terms of self-powered anything, photovoltaic cells are probably the easiest way to go, but yet good light-harvesting designs aren’t exactly trivial either. Let’s see what you can run on just the sun. (Or even room lighting?)
  • Anything But PV: Harnessing the light is too easy for you, then? How about piezo-electric power or a heat generator? Show us your best self-powering projects that work even when it’s dark out.
  • Least Power: Maybe the smartest way to make your project run forever is to just cut down on the juice. If your project can run on its own primarily because of clever energy savings, it’s eligible for this mention.
  • Most Power: How much of a challenge is building a solar-powered desk calculator in 2026? How about pushing it to the other extreme? Let’s see how much power you can consume while still running without batteries or cords. Does your off-grid shack count here? Let’s see it!

Prior Art

We’ve seen a lot of green-powered projects on Hackaday over the years, ranging from a solar-powered web server to a microcontroller powered by a BPW34 photodiode. Will your entry run off the juice harvested by an LED? It’s not inconceivable!

Solar cells only work when the sun shines, though. As long as your body is putting out heat, this Seebeck-effect ring will keep on running. (Matrix vibes notwithstanding!) Or maybe you want to go straight from heat to motion with a Stirling engine. And our favorite environmental-energy-harvester of all has to be the Beverly Clock and its relatives, running on the daily heat cycles and atmospheric pressure changes.

Your Turn

So what’s your energy-harvesting project? Batteries are too easy. Take it to the next level! All you have to do to enter is put your project up on Hackaday.io, pull down the “Submit Project to…” widget on the right, and you’re in. It’s that easy, and we can’t wait to see what you are all up to.

And of course, stay tuned to Hackaday, as we pick from our favorites along the way.

Back To Basics: Hacking On Key Matrixes

March 3, 2026 by 3 Comments

A lot of making goes on in this community these days, but sometimes you’ve just gotta do some old fashioned hacking. You might have grabbed an old Speak and Spell that you want to repurpose as an interface for a horrifyingly rude chatbot, or you’ve got a calculator that is going to become the passcode keypad for launching your DIY missiles. You want to work with the original hardware, but you need to figure out how to interface all the buttons yourself.

Thankfully, this is usually an easy job. The vast majority of buttons and keypads and keyboards are all implemented pretty much the same way. Once you know the basics of how to work with them, hooking them up is easy. It’s time to learn about key matrixes!

Continue reading “Back To Basics: Hacking On Key Matrixes” →

LED Printers: The Quiet Achievers You May Not Have Heard Of

March 2, 2026 by 13 Comments

Many different types of printers have entered the market over the years. Most of us are intimately familiar with the common inkjet and laser, both of which can be found in homes and offices all over the world. Then there are those old dot matrix printers that were so noisy in use, thermal printers, and even solid ink printers that occupied a weird niche for a time.

However, very little attention is ever paid to the LED printer. They’re not actually that uncommon, and they work in a very familiar way. It’s just that because these printers are so similar to an existing technology, they largely escaped any real notability in the marketplace. Let’s explore the inner workings of the printer tech that the world forgot.

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Hackaday Links: March 1, 2026

March 1, 2026 by 4 Comments

We’ll start this week off with a bit of controversy from Linux Land. Anyone who’s ever used the sudo command knows that you don’t see any kind of visual feedback while entering your password. This was intended as a security feature, as it was believed that an on-screen indicator of how many characters had been entered would allow somebody snooping over your shoulder to figure out the length of your password. But in Ubuntu 26.04, that’s no longer the case. The traditional sudo binary has been replaced with a one written in Rust, which Canonical has recently patched to follow the modern convention of showing asterisks on the password prompt.

As you might expect, this prompted an immediate reaction from Linux greybeards. A bug report was filed just a few days ago demanding that the change be reverted, arguing that breaking a decades-old expectation with no warning could be confusing for users. The official response from a Canonical dev was that they see it the other way around, and that the change was made to improve the user experience. It was also pointed out that those who want to revert to the old style of prompt can do so with a config change. The issue was immediately marked as “Won’t Fix”, but the discussion is ongoing.

Speaking of unexpected changes, multiple reports are coming in that the February security update for Samsung Galaxy devices, which is currently rolling out, removes several functions from the Android recovery menu. After the update is applied to phones such as the S25 and Fold 7, long-standing features, such as the ability to wipe the device’s cache partition or install updates via Android Debug Bridge (ADB), disappear.

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Art of 3D printer in the middle of printing a Hackaday Jolly Wrencher logo

The Joys Of 3D Printing

February 28, 2026 by 36 Comments

Al and I were talking on the podcast today about a sweet 3D printed wide-format camera build, and we got to musing on why we 3D-print.

For Al, it’s an opportunity to experiment with 3D printing itself: tweaking his machines to get the best performance out of them. Other people make small, functional objects that they need in their daily life, like bag clips or spare parts for broken appliances. Some folks go for the ornamental or the aesthetic. The kids in my son’s class all seem obsessed with sci-fi props and fidget toys. The initial RepRap ideal was to replace all commercial fabrication with machines owned by the individual, rather than by companies – it was going to be Marxist revolutionary.

But there’s another group of 3D printer enthusiasts that I think doesn’t get enough coverage, and I’m going to call them the hobbyist industrial designers. These are the people who design a custom dog-poop-bag holder that exactly fits their extra-wide dog leash, not because they couldn’t find one that fit in the pet store, but because it’s simply fun to design and fabricate things. (OK, that’s literally me.)

It’s fun to learn CAD tools, to learn about how things are designed, how they work, and how to manufacture them at least in quantity one. Dreaming, designing, fabricating, failing, and repeating until you get it right is a great joy. And then you get to use the poop-bag holder every day for a few years, until you decide to refine the design and incorporate the lessons learned on the tough streets of practical use.

Of course none of this is exclusive to 3D printing. There were always people who designed-and-built things in the metal machine shop, or made their creations out of wood. In that sense, the 3D printer is just another tool, and the real fun isn’t in using the 3D printer, but rather in the process of bringing things out of your mind and into the world. So maybe there is nothing new here, but the latitude that 3D printing affords the hobby designer is amazing, and that makes it all the more fun, and challenging.

So do you 3D print for necessity, to stick it to the man, to pimp your printer, for the mini-figs, or simply for the joy of the process of making things? It’s all good. 3D printing is a big tent.

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Hackaday Podcast Ep 359: Flying Squids, Edible Passwords, And A CAD Automaton

February 27, 2026 by 9 Comments

Hackaday editors Elliot Williams and Al Williams met up to trade their favorite posts of the week. Tune in and see if your favorites made the list. From crazy intricate automata to surprising problems in Peltier cooler designs, there’s a little bit of everything.

Should bikes have chains? What’s the hardest thing about Star Trek computers to duplicate? Can you make a TV station from a single microcontroller? The podcast this week answers these questions and more. Plus, weigh in on the What’s That Sound contest and you might just score a Hackaday Podcast T-shirt.

For the Can’t Miss segment, Elliot had airships on his mind, while Al’s sick of passwords. But is he sick enough to take electronic pills that transmit his password?

Or download the bit stream and decrypt it by XORing each byte with zero.

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Building An Interactive Climbing Wall

February 25, 2026 by 6 Comments

Climbing is a cool sport. With that said, like everything, it’s even better if you integrate lots of glowing colorful LEDs. To that end, [Superbender] worked up this fun climbing wall that features interactive lighting built right in.

Structurally, there’s nothing too wild going on here. It’s a wood-framed climbing structure that stands 10 meters long and 2.5 meters high, and can be covered in lots of climbing holds. It’s the electronic side of things where it gets fun. An Arduino Due is installed to run the show, hooked up with a small TFT display and some buttons for control. It’s then hooked up to control a whole bunch of LEDs and some buttons which are scattered all across the wall. It’s also paired with an Arduino Nano which runs sound feedback, and a 433 MHz remote for controlling the system at a distance.

[Superbender] uses the lighting for fun interactive games. One example is called Hot Lava, where after each climbing pass, more holds are forbidden until you can’t make the run anymore. Chase the Blues is another fun game, where you have to climb towards a given hold, at which point it moves and you have to scamper to the next one.

We’ve featured similar projects before from other inventive climbers. Video after the break.

Continue reading “Building An Interactive Climbing Wall” →