TechyMagThings

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.

Unlike on Earth there aren’t dozens of satellites whizzing around Mars to provide satellite navigation functionality. Recently NASA’s JPL engineers tried something with the Perseverance Mars rover that can give such Marsbound vehicles the equivalent of launching GPS satellites into Mars orbit, by introducing Mars Global Localization.

Although its remote operators back on Earth have the means to tell the rover where it is, it’d be incredibly helpful if it could determine this autonomously so that the rover doesn’t have to constantly stop and ask its human operators for directions. To this end the processor which was originally used to communicate with its Ingenuity helicopter companion was repurposed, reprogrammed to run an algorithm that compares panoramic images from the rover’s navigation cameras with its onboard orbital terrain maps.

Much like terrain-based navigation as used in cruise missiles back on Earth, this can provide excellent results depending on how accurate your terrain maps are. This terrain mapping process used to be done back on Earth, but for the past years engineers have worked to give the rover its own means to perform this task.

Because the off-the-shelf processor in the rover’s Helicopter Base Station (HBS) is much faster than the custom, radiation-hardened processors that control the rover, the decision was made to try the algorithm on the HBS, especially since Ingenuity was left behind after it fatally damaged its propeller during a rough landing. This left the HBS unused and free to be repurposed.

Repurposing such OTS hardware also provided a good way to check for radiation damage to such standard hardware that was never certified for high radiation environments. To validate reliability the algorithm was run multiple times on the HBS, with the results compared by the main computer. This found some discrepancies, attributed to damage to about 25 bits out of 1 GB of RAM.

By isolating these damaged bits, the algorithm could run reliably, while giving another nod to the genius of the Ingenuity program that enabled such new features with what was at the time an unproven and relatively low-budget side-project tacked onto the Perseverance rover.

Thanks to [Nevyn] for the tip.

Historically, moving and pointing a camera while filming was the job of a highly-skilled individual. However, there are machines that can do that, enabling all kinds of fancy movement that is difficult or impossible for a human to recreate. A great example is this pan-tilt build from [immofoto3d.]

The build uses a hefty cradle to mount DSLR-size cameras or similar. It’s controlled in the tilt axis by a chunky NEMA 17 stepper motor hooked up to a belt drive for smooth, accurate movement. Similarly, another stepper motor handles the pan axis, with an option for upgrade if you have a heavier camera rig that needs more torque to spin easily. Named Gantry Bot, it’s an open-source design with source files available, so you can make any necessary tweaks on your own. You will have to bring your own control mechanism, though—telling the stepper motors what to do and how fast to do it is up to you.

It’s a heavy-duty build, this one, and you’ll really want a decent metal-capable CNC to get it done, along with a 3D printer for all the plastic pieces. With that said, we’ve featured some other similar builds that might be more accessible if you don’t have a hardcore machine shop in the basement. If you’ve got your own impressive motion rig in the works, be sure to notify the tipsline!

Considering that the Serial Peripheral Interface bus semi-standard has been around since the early 1980s, it’s perhaps not that shocking that the controllers of the Super Nintendo Entertainment System (SNES) would take at least some strong design hints for the used protocol. This does however raise the question of exactly how compatible a SNES controller is when connected to the SPI master peripheral of any random MCU. Recently [James Sharman] set out to answer this question decisively.

The impetus for answering this question came after [James] designed a separate SNES controller board for his homebrew computer system, which led to many comments on that video saying that he could just have hooked the controller up to the SPI board in said homebrew system.

Here the short answer is that the SNES controller protocol is very close to SPI Mode-1, with a similar arrangement of clock/data/chip select (latch) lines and clocking. If you think of the SNES controller as an SPI device with just a MISO line, you’re basically there already. The only niggle that popped up was that the ‘MISO’ line does not get pulled into a high-impedance state when the active-low latch connection is pulled high.

This was fixable by introducing a 74HC125 tri-state buffer IC, after which both the original SD card and twin SNES controllers could be used simultaneously.

There are many chess robots, most of which require the human player to move the opposing pieces themselves, or have a built-in mechanism that can slide the opposing pieces around to their new location. Ideally, such a chess robot would move the pieces just like how a human would, of course. That’s pretty much the promise behind the Manya Cynus chess robot, which [Matt] over at the Techmoan YouTube channel bought from the Kickstarter campaign.

Advertising itself as a ‘Portable AI Chess Robot’, the Manya Cynus chess robot comes in the form of a case that unfolds into a chess board and also contains the robotic arm that contains the guts of the operation. Powered by the open source Stockfish chess engine, it can play games against a human opponent at a few difficulty levels without requiring any online connectivity or a companion app. It moves its own pieces by picking up the metal-cored chess pieces with its arm, while its front display tries to display basic emotions with animated eyes. A 3-MP downward-facing camera is located on the head section, along with a microphone.

As for how well it works, [Matt] isn’t the best chess player, but he had a fair bit of fun with the machine. His major complaints circle around how unfinished the firmware still feels, with e.g., invalid moves basically ignored with only a barely visible warning popping up on the screen. In general, he’d rather classify it as an interesting development kit for a chess robot, which is where the BLE 5.1-based interface and a purported Python-based development environment provided by Manya seem to come into focus.

From the site, it’s not clear where this documentation and software can be found, and the chess robot appears to be fully sold out on the Kickstarter page. In addition to this, a promised companion app seems to have gone AWOL, too.

With no clear support or even availability, it would seem that this is less of a crowdfunding scam and more of a confusing product which may or may not become available again, yet which could perhaps provide inspiration to some DIY projects, as the basic principle seems sound enough. Or, keep it simple and use a gantry.

[Nagy Krisztián] had an Intel 286 CPU, only… There was no motherboard to install it in. Perhaps not wanting the processor to be lonely, [Nagy] built a simulated system to bring the chip back to life.

The concept is simple enough. [Nagy] merely intended to wire the 286 up to a Raspberry Pi Pico that could emulate other parts of a computer that it would normally expect to talk to. This isn’t so hard with an ancient CPU like the 286, which has just 68 pins compared to the 1000+ pins on modern CPUs. All it took was a PLCC-68 socket, an adapter PCB, a breadboard, and some MCP23s17 logic expanders to give the diminutive microcontroller enough I/O. With a bit of work, [Nagy] was able to get the Pi Pico running the 286, allowing it to execute a simple program that retrieves numbers from “memory” and writes them back in turn.

Notably, this setup won’t run the 286 at its full clock speed of 12 MHz, and it’s a long way off from doing anything complex like talking to peripherals or booting an OS. Still, it’s neat to see the old metal live again, even if it’s just rattling through a few simple machine instructions that don’t mean a whole lot. [Nagy] equates this project to The Matrix; you might also think of it as a brain in a jar. The 286 is not in a real computer; it’s just hooked up to a microcontroller stimulating its various pins in a way that is indistinguishable from its own perspective.

We’ve seen similar retro projects before, such as this FPGA rig that helped a NEC V20 get back on its feet. If you’re doing your own tinkering on the platforms of yesteryear, we probably want to know about it on the tips line.

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.

Just like with the change to sudo, this is the sort of thing that will aggravate veteran users the most. There’s been no official explanation for these changes, and it’s not immediately obvious why Samsung would fiddle with the recovery menu that’s remain largely unchanged since Android’s introduction. As 9to5Google mentions, it could be an attempt to prevent users from installing leaked firmware builds — a practice that’s gotten the attention of the electronic giant’s legal department.

These days, software updates are just one of the things you need to keep track of. Add in emails, RSS feeds, and incoming chat messages, and keeping up with the notifications on your computer or smartphone can be a challenge. But that’s nothing compared to the 800,000 alerts fired off earlier this week by the Vera Rubin Observatory. The observatory uses a 3.2 gigapixel camera to take long exposure images of the night sky, which are then compared with earlier shots to detect visual changes. Astronomers create filters to narrow down what they’re after, and can be notified when the automated system detects a match. A preview image is available in just seconds, while the full-resolution imagery takes around 80 hours to process. It’s still early days, but once the VRO gets up to speed, it’s expected that as many as seven million alerts will be generated each night.

While on the subject of large-scale engineering projects, this week, Google announced that its new data center in Minnesota will be hooked up to the world’s largest battery. The 300 megawatt array built by Form Energy will use iron-air technology, which essentially uses a reversible rusting process to store energy produced by renewable sources such as wind and solar. When those sources aren’t available, the data center can run off of battery power for up to 100 hours.

While heavier and less efficient than lithium-ion, iron-air batteries have the advantage of being substantially cheaper to produce. So while it’s unlikely you’ll see the technology in smartphones anytime soon, it’s perfect for static installations like this.

Finally, some sad news from the world of retro computing/games: a very rare copy of Tsukihime Trial Edition was apparently destroyed while in transit from one collector to another. It might not look like much — the game was distributed by the indie developers on unbranded floppies at a Japanese convention in 1999 — but it represents one of only 50 copies known to exist. While the occasional damaged package is all but unavoidable, this one is particularly egregious as it appears that someone at US Customs intentionally ripped the disk to pieces. The purchaser has filed a complaint with Customs, and we’re interested in hearing what their version of the story sounds like.

See something interesting that you think would be a good fit for our weekly Links column? Drop us a line, we’d love to hear about it.