Turning trash into art is something we undoubtedly all admire. [Davis DeWitt] did just that with a massive mural made entirely from discarded receipt paper. [Davis] got lucky while doing some light dumpster diving, where he stumbled upon the box of thermal paper rolls. He saw the potential them and, armed with engineering skills and a rental-friendly approach, set out to create something original.

The journey began with a simple test: how long can a receipt be printed, continuously? With a maximum length of 10.5 feet per print, [Davis] designed an image for the mural using vector files to maintain a high resolution. The scale of the project was a challenge in itself, taking over 13 hours to render a single image at the necessary resolution for a mural of this size. The final piece is 30 foot (9.144 meters) wide and 11 foot (3.3528 meters) tall – a pretty conversational piece in anyone’s room – or shop, in [Davis]’ case.

Once the design was ready, the image was sliced into strips that matched the width of the receipt paper. Printing over 1,000 feet of paper wasn’t without its issues, so [Davis] designed a custom spool system to undo the curling of the receipts. Hanging the mural involved 3D-printed brackets and binder clips, allowing the strips to hang freely with a kinetic effect.

Though the thermal paper will fade over time, the beauty of this project lies in its adaptability—just reprint any faded strips. Want to see how it all came together? Watch the full process here.

What if GPS had existed in 1565? No satellites or microelectronics, sure—but let’s play along. Imagine the bustling streets of Antwerp, where merchants navigated the sprawling city with woodcut maps. Or sailors plotting Atlantic crossings with accuracy unheard of for the time. This whimsical intersection of history and tech was recently featured in a blog post by [Jan Adriaenssens], and comes alive with Bert Spaan’s Allmaps Here: a delightful web app that overlays your GPS location onto georeferenced historical maps.

Take Antwerp’s 1565 city map by Virgilius Bononiensis, a massive 120×265 cm woodcut. With Allmaps Here, you’re a pink dot navigating this masterpiece. Plantin-Moretus Museum? Nailed it. Kasteelpleinstraat? A shadow of the old citadel it bordered. Let’s not forget how life might’ve been back then. A merchant could’ve avoided morning traffic and collapsing bridges en route to the market, while a farmer relocating his herd could’ve found fertile pastures minus the swamp detour.

Unlike today’s turn-by-turn navigation, a 16th-century GPS might have been all about survival: avoiding bandit-prone roads, timing tides for river crossings, or tracking stars as backup. Imagine explorers fine-tuning their Atlantic crossings with trade winds mapped to the mile. Georeferenced maps like these let us re-imagine the practical genius of our ancestors while enjoying a modern hack on a centuries-old problem.

Although sites like OldMapsOnline, Google Earth Timelapse (and for the Dutch: TopoTijdreis) have been around for a while, this new match of technology and historical detail is a true gem. Curious to map your own world on antique charts? Navigate to Allmaps and start georeferencing!

When it comes to space exploration, we often think of billion-dollar projects—NASA’s Artemis missions, ESA’s Mars rovers, or China’s Tiangong station. Yet, a group of U.S. students at USC’s Rocket Propulsion Lab (RPL) has achieved something truly extraordinary—a reminder that groundbreaking work doesn’t always require government budgets. On October 20, their homemade rocket, Aftershock II, soared to an altitude of 470,000 feet, smashing the amateur spaceflight altitude and speed records held for over two decades. Intrigued? Check out the full article here.

The 14-foot, 330-pound rocket broke the sound barrier within two seconds, reaching hypersonic speeds of Mach 5.5—around 3,600 mph. But Aftershock II didn’t just go fast; it climbed higher than any amateur spacecraft ever before, surpassing the 2004 GoFast rocket’s record by 90,000 feet. Even NASA-level challenges like thermal protection at hypersonic speeds were tackled using clever tricks. Titanium-coated fins, specially engineered heat-resistant paint, and a custom telemetry module ensured the rocket not only flew but returned largely intact.

This achievement feels straight out of a Commander Keen adventure—scrappy explorers, daring designs, and groundbreaking success against all odds. The full story is a must-read for anyone dreaming of building their own rocket.

If you’re into hacking hardware and bending light to your will, [Shoaib Mustafa]’s latest project is bound to spike your curiosity. Combining lasers to project multi-colored beams onto a screen is ambitious enough, but doing it with a galvanomirror, STM32 microcontroller, and mostly scratch-built components? That’s next-level tinkering. This project isn’t just a feast for the eyes—it’s a adventure of control algorithms, hardware hacks, and the occasional ‘oops, that didn’t work.’ You can follow [Shoaib]’s build log and join the journey here.

The nitty-gritty is where it gets fascinating. Shoaib digs into STM32 Timers, explaining how modes like Timer, Counter, and PWM are leveraged for precise control. From adjusting laser intensity to syncing galvos for projection, every component is tuned for maximum flexibility. Need lasers aligned? Enter spectrometry and optical diffusers for precision wavelength management. Want real-time tweaks? A Python-controlled GUI handles the instruments while keeping the setup minimalist. This isn’t just a DIY build—it’s a work of art in problem-solving, with successes like a working simulation and implemented algorithms along the way.

If laser projection or STM32 wizardry excites you, this build will inspire. We featured a similar project by [Ben] back in September, and if you dig deep into our archives, you can eat your heart out on decades of laser projector projects. Explore Shoaib’s complete log on Hackaday.io. It is—literally—hacking at its most brilliant.

If you’re into CNC machining, mechanical tinkering, or just love a good engineering rabbit hole, you’re in for a treat. Substack’s [lcamtuf] has written a quick yet insightful 15-minute introduction to involute gears that’s as informative as it is accessible. You can find the full article here. Compared to Hackaday’s more in-depth exploration in their Mechanisms series over the years, this piece is a beginner-friendly gateway into the fascinating world of gear design.

Involute gears aren’t just pretty spirals. Their unique geometry minimizes friction and vibration, keeps rotational speeds steady, and ensures smooth torque transfer—no snags, no skips. As [lcamtuf] points out, the secret sauce lies in their design, which can’t be eyeballed. By simulating the meshing process between a gear and a rack (think infinite gear), you can create the smooth, rolling movement we take for granted in everything from cars to coffee grinders.

From pressure angles to undercutting woes, [lcamtuf] explores why small design tweaks matter. The pièce de résistance? Profile-shifted gears—a genius hack for stronger teeth in low-tooth-count designs.

Whether you’re into the theory behind gear ratios, or in need of a nifty tool to cut them at home, Hackaday has got you covered. Inspired?

Tinkerers and tech enthusiasts, brace yourselves: the frontier of biohacking has just expanded. Picture implantable medical devices that don’t need batteries—no more surgeries for replacements or bulky contraptions. Though not all new (see below), ChemistryWorld recently shed new light on these innovations. It’s as exciting as it is unnerving; we, as hackers, know too well that tech and biology blend a fine ethical line. Realising our bodies can be hacked both tickles our excitement and unsettlement, posing deeper questions about human-machine integration.

Since the first pacemaker hit the scene in 1958, powered by rechargeable nickel-cadmium batteries and induction coils, progress has been steady but bound by battery limitations. Now, researchers like Jacob Robinson from Rice University are flipping the script, moving to designs that harvest energy from within. Whether through mechanical heartbeats or lung inflation, these implants are shifting to a network of energy-harvesting nodes.

From triboelectric nanogenerators made of flexible, biodegradable materials to piezoelectric devices tapping body motion is quite a leap. John Rogers at Northwestern University points out that the real challenge is balancing power extraction without harming the body’s natural function. Energy isn’t free-flowing; overharvesting could strain or damage organs. A topic we also addressed in April of this year.

As we edge toward battery-free implants, these breakthroughs could redefine biomedical tech. A good start on diving into this paradigm shift and past innovations is this article from 2023. It’ll get you on track of some prior innovations in this field. Happy tinkering, and: stay critical! For we hackers know that there’s an alternative use for everything!

On November 6th, Northwestern University introduced a groundbreaking leap in haptic technology, and it’s worth every bit of attention now, even two weeks later. Full details are in their original article. This innovation brings tactile feedback into the future with a hexagonal matrix of 19 mini actuators embedded in a flexible silicone mesh. It’s the stuff of dreams for hackers and tinkerers looking for the next big thing in wearables.

What makes this patch truly cutting-edge? First, it offers multi-dimensional feedback: pressure, vibration, and twisting sensations—imagine a wearable that can nudge or twist your skin instead of just buzzing. Unlike the simple, one-note “buzzers” of old devices, this setup adds depth and realism to interactions. For those in the VR community or anyone keen on building sensory experiences, this is a game changer.

But the real kicker is its energy management. The patch incorporates a ‘bistable’ mechanism, meaning it stays in two stable positions without continuous power, saving energy by recycling elastic energy stored in the skin. Think of it like a rubber band that snaps back and releases stored energy during operation. The result? Longer battery life and efficient power usage—perfect for tinkering with extended use cases.

And it’s not all fun and games (though VR fans should rejoice). This patch turns sensory substitution into practical tech for the visually impaired, using LiDAR data and Bluetooth to transmit surroundings into tactile feedback. It’s like a white cane but integrated with data-rich, spatial awareness feedback—a boost for accessibility.

Fancy more stories like this? Earlier this year, we wrote about these lightweight haptic gloves—for those who notice, featuring a similar hexagonal array of 19 sensors—a pattern for success? You can read the original article on TechXplore here.

In the quest for faster computing, modern CPUs have turned to innovative techniques to optimize instruction execution. One such technique, register renaming, is a crucial component that helps us achieve the impressive multi-tasking abilities of modern processors. If you’re keen on hacking or tinkering with how CPUs manage tasks, this is one concept you’ll want to understand. Here’s a breakdown of how it works and you can watch the video, below.

In a nutshell, register renaming allows CPUs to bypass the restrictions imposed by a limited number of registers. Consider a scenario where two operations need to access the same register at once: without renaming, the CPU would be stuck, having to wait for one task to complete before starting another. Enter the renaming trick—registers are reassigned on the fly, so different tasks can use the same logical register but physically reside in different slots. This drastically reduces idle time and boosts parallel tasking. Of course, you also have to ensure that the register you are using has the correct contents at the time you are using it, but there are many ways to solve that problem. The basic technique dates back to some IBM System/360 computers and other high-performance mainframes.

Register renaming isn’t the only way to solve this problem. There’s a lot that goes into a superscalar CPU.

Would you believe that the first large-scale virtual meeting happened as early as 1916? More than a century before Zoom meetings became just another weekday burden, the American Institute of Electrical Engineers (AIEE) pulled off an unprecedented feat: connecting 5,100 engineers across eight cities through an elaborate telephone network. Intrigued? The IEEE, the successor of the AIEE, just published an article about it.

This epic event stretched telephone lines over 6,500 km, using 150,000 poles and 5,000 switches, linking major hubs like Atlanta, Boston, Chicago, and San Francisco. John J. Carty banged the gavel at 8:30 p.m., kicking off a meeting in which engineers listened in through seat-mounted receivers—no buffering or “Can you hear me?” moments. Even President Woodrow Wilson joined, sending a congratulatory telegram. The meeting featured “breakout sessions” with local guest speakers, and attendees in muted cities like Denver sent telegrams, old-school Zoom chat style.

The event included musical interludes with phonograph recordings of patriotic tunes—imagine today’s hold music, but gloriously vintage. Despite its success, this wonder of early engineering vanished from regular practice until our modern virtual meetings.

We wonder if Isaac Asimov knew about this when he wrote about 3D teleconferencing in 1953. If you find yourself in many virtual meetings, consider a one-way mirror.

Space and mystery always spark our curiosity, so when we stumbled upon the story of Skynet-1A, Britain’s first communication satellite from 1969, we knew it was worth exploring. The BBC recently highlighted its unexpected movement across the sky – you can check out their full coverage here. The idea that this half-century-old hunk of metal mysteriously shifted orbits leaves us with more questions than answers. Who moved Skynet-1A, and why?

Launched just months after the Apollo 11 Moon landing, Skynet-1A stood as a symbol of Cold War innovation, initially placed above East Africa to support British military communications. But unlike the silent drift of inactive satellites heading naturally eastward, Skynet-1A defied orbital norms, popping up halfway across the globe above the Americas. This wasn’t mere chance; someone or something had made it fire its thrusters, likely in the mid-1970s.

Experts like Dr. Stuart Eves and UCL’s Rachel Hill suggest the possibility of control being temporarily transferred to the US, particularly during maintenance periods at the UK’s RAF Oakhanger. Still, the specifics remain buried in lost records and decades-old international collaborations. Skynet-1A’s journey serves as a stark reminder of the persistent challenges in space and the gaps in our historical data.

Looking for more space oddities? Hackaday has some interesting articles on space debris. You can read the original BBC article here.

Retro computing enthusiasts, rejoice! HIDman, [rasteri]’s latest open source creation, bridges the gap between modern USB input devices and vintage PCs, from the IBM 5150 to machines with PS/2 ports. Frustrated by the struggle to find functioning retro peripherals, [rasteri] developed HIDman as an affordable, compact, and plug-and-play solution that even non-techies can appreciate.

The heart of HIDman is the CH559 microcontroller, chosen for its dual USB host ports and an ideal balance of power and cost-efficiency. This chip enables HIDman’s versatility, supporting serial mice and various keyboard protocols. Building a custom parser for the tricky USB HID protocol posed challenges, but [rasteri]’s perseverance paid off, ensuring smooth communication between modern devices and older systems.

Design-wise, the project includes a thoughtful circuit board layout that fits snugly in its case, marrying functionality with aesthetics. Retro computing fans can jump in by building HIDman themselves using the files in the GitHub repository, or by opting for the ready-made unit.

In the world of retro gaming, some legends never die – especially the ‘phantom’ PSP, Sony’s mythical handheld that never saw the light of day. While that elusive device remains a dream, hacker and gaming wizard [Kyle Brinkerhoff] built his own – and Macho Nacho made a video about it. His creation, which also goes by the name ‘Playstation Zero’, isn’t just another handheld emulator; it’s a powerful, custom-built system that revives the classics and plays them on a portable device that feels like the future.

Driven by a hunger for the ultimate gaming experience, [Kyle] set out to blend modern tech with retro gaming magic. He started with the Raspberry Pi, loading it up with emulation software for all the iconic systems—from NES and SNES to the Sega Genesis and Game Boy. But [Kyle] didn’t just slap on an off-the-shelf emulator; he dived into the code himself, optimizing and tweaking for lightning-fast responsiveness, so each game plays like it’s running on the original hardware. That’s hacking in true form: pushing the limits of software and hardware until they work exactly the way you want them to. Best of all: he published it all open source for others to use.

In the spirit of the Geneboy—a handheld Sega Genesis built by [Downing] and featured on Hackaday back in 2012—[Kyle]’s device pairs handheld emulation with the consoles all nineties kids wanted for Christmas. To capture the tactile thrill of vintage gaming, [Kyle] went a step further by designing and 3D-printing a custom controller layout that mimics the feel of the original systems. If watching someone neatly soldering a pcb sounds relaxing to you, don’t skip the middle part of his video. Although this little beast is packed with all bells and whistles you’d expect to see on a Raspberry Pi, it does lack one serious thing: battery life. But, [Kyle] is open about that, and hopes to improve on that in a future version.

If you want to see the full build, check out the video below. Or, immediately dive into [Kyle]’s Github, order the cute Takara shell, and get started!

In a world of digital monotony, the Avo DA14 digital multimeter, with its vintage J Nixie tube charm, is a refreshing gem. Recently refurbished by [Thomas Scherrer], this multimeter video review is a blend of nostalgia and tech savvy. The DA14 not only has style, but substance — delivering resistance, current, and voltage measurements that make you wonder why more multi-meters didn’t stick with this stylish glow.

As [Thomas] starts by powering up the DA14, we were instantly captivated as the Nixie tubes illuminate in their retro orange. With each twist of the dial, he demonstrates just how intuitive the multimeter is to operate, walking us viewers through each function while giving some extra love to its calibration process—a neat front-panel potentiometer that requires just a touch of finesse to get perfect readings.

But, as with all good tinkering tales, things go downhill when issues with analog inputs and the display pop up. A teardown reveals a beautifully complex inner assembly of transformers, rectifiers, and circuit boards, giving the DA14 its impressive yet fragile structure. When the critical defective display chip is found, hopes for a full repair dim. His story ends without a revival, but if you want to see a similar attempt that did get resurrected – albeit without those nixie digits – take a look at this LCD transplant we covered previously.