You wouldn’t typically associate graphing calculators with artificial intelligence, but hacker [KermMartian] recently made it happen. The innovative project involved running a neural network directly on a TI-84 Plus CE to recognize handwritten digits. By using the MNIST dataset, a well-known collection of handwritten numbers, the calculator could identify digits in just 18 seconds. If you want to learn how, check out his full video on it here.

The project began with a proof of concept: running a convolutional neural network (CNN) on the calculator’s limited hardware, a TI-84 Plus CE with only 256 KB of memory and a 48 MHz processor. Despite these constraints, the neural network could train and make predictions. The key to success: optimizing the code, leveraging the calculator’s C programming tools, and offloading the heavy lifting to a computer for training. Once trained, the network could be transferred to the calculator for real-time inference. Not only did it run the digits from MNIST, but it also accepted input from a USB mouse, letting [KermMartian] draw digits directly on the screen.

While the calculator’s limited resources mean it can’t train the network in real-time, this project is a proof that, with enough ingenuity, even a small device can be used for something as complex as AI. It’s not just about power; it’s about resourcefulness. If you’re into unconventional projects, this is one for the books.

Rope-climbing robots are the stuff of engineering dreams. As kids, didn’t we all clutter our family home with constructions of towers and strings – Meccano, or Lego – to have ziplines spanning entire rooms? Good for the youngsters of today, this has been included in school curricula. At the University of Illinois, the ME 370 students have been given the task of building a robot that can hang from a rope and walk across it—without damaging the rope. The final projects show not only how to approach tricky design problems, but also the creative solutions they stumbled upon.

Imagine a tiny, rope-climbing walker in your workshop—what could you create?

The project is full of opportunities for those thinking out of the box. It’s all about the balance between innovation and practicality: the students have to come up with a solution that can move at least 2 meters per minute, fits in a shoebox, and has some creative flair—no wheels allowed! The constraints provide an extra layer of challenge, but that’s where the fun lies. Some students use inverted walkers, others take on a more creature-like approach. The clever use of motors and batteries shows just how far simple tech can go when combined with a bit of engineering magic.

This project is a fantastic reminder that even small, seemingly simple design challenges can lead to fascinating creations. It invites us adults to play, and by that, we learn: a win-win situation. You can find the original article here, or grab some popcorn and watch the video below.

Each Christmas, [Adam Anderson], [Daniel Quach], and [Johan Wheeler] (going by ‘the Janky Jingle Crew’)—set themselves the challenge of outdoing their previous creations. Last year’s CH32 Fireplace brought an animated LED fire to life with CH32V003 microcontrollers.

This year, they’ve gone a step further with the North Pole Circuit, a holiday project that combines magnetic propulsion, festive decorations, and a bit of engineering flair. Inspired by a miniature speedway based on Friedrich Gauss’ findings, the North Pole Circuit includes sleighs and reindeer that glide along a custom PCB track, a glowing village with flickering lights, and a buzzer to play Christmas tunes.

The propulsion system works using the Lorentz force, where vertical magnets interact with PCB traces to produce motion. A two-phase design, similar to a stepper motor, ensures smooth operation, while guard rails maintain stability on curves. A separate CH32V003 handles lighting and synchronized jingles, creating a cohesive festive display. As we mentioned in the article on their last year’s creation, going from a one-off to a full batch will make one rethink the joy of repetitive production. Consider the recipients of these tiny Christmas cards quite the lucky ones. We deem this little gift a keeper to put on display when Christmas rolls around again.

This annual tradition highlights the Crew’s knack for combining fun and engineering. Curious about the details or feeling inspired to create your own? Explore the full details and files on their GitHub.

Among us Hackaday writers, there are quite a few enthusiasts for retro artifacts – and it gets even better when they’re combined in an unusual way. So, when we get a tip about a build like this by [Sam Christy], our hands sure start itching.

The story of this texting typewriter is one that beautifully blends nostalgia and modern technology. [Sam], an engineering teacher, transformed a Panasonic T36 typewriter into a device that can receive SMS messages, print them out, and even display the sender’s name and timestamp. For enthusiasts of retro gadgets, this creation bridges the gap between analog charm and digital convenience.

What makes [Sam]’s hack particularly exciting is its adaptability. By effectively replacing the original keyboard with an ESP32 microcontroller, he designed the setup to work with almost any electric typewriter. The project involves I2C communication, multiplexer circuits, and SMS management via Twilio. The paper feed uses an “infinite” roll of typing paper—something [Sam] humorously notes as outlasting magnetic tape for storage longevity.

Beyond receiving messages, [Sam] is working on features like replying to texts directly from the typewriter. For those still familiar with the art form of typing on a typewriter: how would you elegantly combine these old machines with modern technology? While you’re thinking, don’t overlook part two, which gives a deeper insight in the software behind this marvel!

When it comes to aviation curiosities, few machines captivate the imagination like the Fairey Rotodyne. This British hybrid aircraft was a daring attempt to combine helicopter and fixed-wing efficiency into a single vehicle. A bold experiment in aeronautical design, the Rotodyne promised vertical takeoffs and landings in cramped urban spaces while offering the speed and range of a regional airliner. First flown in 1957, it captured the world’s attention but ultimately failed to realize its potential. Despite featured before, new footage keeps fascinating us. If you have never heard about this jet, keep reading.

The Rotodyne’s innovative design centered around a massive, powered rotor that utilized a unique tip-jet system. Compressed air, mixed with fuel and ignited at the rotor tips, created lift without the need for a tail rotor. The result: a smoother transition between vertical and forward flight modes. Inside, it offered spacious seating for 50 passengers and even had clamshell doors for cargo. Yet its futuristic approach wasn’t without drawbacks—most notably, the thunderous noise produced by its rotor jets, earning complaints from both city planners and residents.

Despite these hurdles, the helicopter-plane crossover demonstrated its versatility, setting a world speed record and performing groundbreaking intercity flights. Airlines and militaries expressed interest, but escalating development costs and noise concerns grounded this ambitious project.

To this day, the Rotodyne remains a symbol of what could have been—a marvel of engineering ahead of its time. Interested in more retro-futuristic aircraft tales? Read our previous story on it, or watch the original footage below and share your thoughts.

Playing Star Wars Outlaws sparked an idea with [3DSage]: why not recreate the game’s wrist communicator as a functioning gadget? Inspired by the relatively simplistic design, he and his friend Ben set out to build their own device to take to Galaxy’s Edge in Disneyland. Armed with an arsenal of tools—3D printers, CNC machines, and soldering irons—he aimed to turn imagination into reality.

After ordering multiple walkie-talkies, they meticulously tested each one for audio quality, circuit board size, and compatibility with custom components. The ‘world’s tiniest walkie-talkie’ had potential but demanded creative modifications, including disassembling and resoldering components. They crafted their own circuit board and designed a 3D printed housing to fit both electronics and style. For the finishing touch, they weathered the device with paints and even glow-in-the-dark accents, making it authentic to the Star Wars universe. Even Chewbacca himself gave one a thumbs-up!

Weathering goes a long way towards creating a convincing prop — it can turn a bundle of pipes and some foam blocks into a movie-ready WWII machine gun.

London, Ontario college student [Victoria Korhonen] has captured the attention of tech enthusiasts and miniaturization lovers with her creation of what might be the world’s smallest arcade machine. Standing just 64 mm tall, 26 mm wide, and 30 mm deep, this machine is a scaled-down marvel playing the classic Atari game PONG. While the record isn’t yet official—it takes about three months for Guinness to certify—it’s clear [Korhonen]’s creation embodies ingenuity and dedication.

[Korhonen], an electromechanical engineering student, took six months to design and build this micro arcade. Inspired by records within reach, she aimed to outdo the previous tiniest arcade machine by shaving off just a few millimeters During the project she faced repeated failures, but viewed each iteration as a step towards success. Her miniature machine isn’t just a gimmick; it’s fully functional, with every component—from paddle mechanics to coding—developed from scratch.

[Korhonen] is already eyeing new projects, including creating the smallest humanoid robot. She also plans to integrate her electromechanical expertise into her family’s escape room business. Her journey aligns with other hobbyist projects pushing the limits of miniaturization, such as this credit card-sized Tetris clone or [Aliaksei Zholner]’s paper micro engines.

Ever wondered how it feels to have the Sorting Hat decide your fate? [Will Dana] wanted to find out, so he conjured a bit of Hogwarts magic, and crafted a fully animatronic Sorting Hat from scratch. In the video below, he covers every step of bringing this magical purple marvel to life—from rapid joystick movements to the electronics behind it all.

The heart of the project is two 9g servos—one actuates the mouth, and the other controls the eyebrows—powered by an ESP32 microcontroller. Communication between two ESP32 boards ensures smooth operation via the ESP-NOW protocol, making this a wireless wonder. The design process involved using mechanical advantage to solve jittery servo movements, a trick that will resonate with anyone who’s fought with uncooperative motors.

If animatronics or themed projects excite you, Hackaday has covered similar builds, from a DIY BB-8 droid to a robot fox.

If you’ve ever wanted to merge the worlds of holiday cheer and clever geometry, [Kris Wilk]’s gingerbread house hack is your ultimate inspiration. Shared in a mesmerising video, [Wilk] showcases his 2024 entry for his neighborhood’s gingerbread house contest. Designed in FreeCAD and baked to perfection, this is no ordinary holiday treat. His pièce de résistance was a brilliant trompe l’oeil effect, visible only from one carefully calculated angle. Skip to the last twenty seconds of the video to wrap your head around how it actually looks.

[Wilk] used FreeCAD’s hidden true perspective projection function—a rarity in CAD software. This feature allowed him to calculate the perfect forced perspective, essential for crafting the optical illusion. The supporting structures were printed on a Prusa MK4, while the gingerbread itself was baked at home. Precision photography captured the final reveal, adding a professional touch to this homemade masterpiece. [Wilk]’s meticulous process highlights how accessible tools and a sprinkle of curiosity can push creative boundaries.

For those itching to experiment with optical illusions, this bakery battle is only the beginning. Why not build a similar one inside out? Or construct a gingerbread man in the same way? Fire up the oven, bend your mind, and challenge your CAD skills!

Imagine the power to clone your favorite LEGO piece—not just any piece, but let’s say, one that costs €50 second-hand. [Balazs] from RacingBrick posed this exact question: can a 3D scanner recreate LEGO pieces at home? Armed with Creality’s CR-Scan Otter, he set out to duplicate a humble DUPLO sheep and, of course, tackle the holy grail of LEGO collectibles: the rare LEGO goat.

The CR-Scan Otter is a neat gadget for hobbyists, capable of capturing objects as small as a LEGO piece. While the scanner proved adept with larger, blocky pieces, reflective LEGO plastic posed challenges, requiring multiple scans for detailed accuracy. With clever use of 3D printed tracking points, even the elusive goat came to life—albeit with imperfections. The process highlighted both the potential and the limitations of replicating tiny, complex shapes. From multi-colored DUPLO sheep to metallic green dinosaur jaws, [Balazs]’s experiments show how scanners can fuel customization for non-commercial purposes.

For those itching to enhance or replace their builds, this project is inspiring but practical advice remains: cloning LEGO pieces with a scanner is fun but far from plug-and-play. Check out [Balazs]’s exploration below for the full geeky details and inspiration.

In an astonishing blend of robotics and nature, SMEO—a robot rat designed by researchers in China and Germany — is fooling real rats into treating it like one of their own.

What sets SMEO apart is its rat-like adaptability. Equipped with a flexible spine, realistic forelimbs, and AI-driven behavior patterns, it doesn’t just mimic a rat — it learns and evolves through interaction. Researchers used video data to train SMEO to “think” like a rat, convincing its living counterparts to play, cower, or even engage in social nuzzling. This degree of mimicry could make SMEO a valuable tool for studying animal behavior ethically, minimizing stress on live animals by replacing some real-world interactions.

For builders and robotics enthusiasts, SMEO is a reminder that robotics can push boundaries while fostering a more compassionate future. Many have reservations about keeping intelligent creatures in confined cages or using them in experiments, so imagine applying this tech to non-invasive studies or even wildlife conservation. In a world where robotic dogs, bees, and even schools of fish have come to life, this animatronic rat sounds like an addition worth further exploring. SMEO’s development could, ironically, pave the way for reducing reliance on animal testing.

We tinkerers often have ideas we know are crazy, and we make them up in the most bizarre places, too. For example, just imagine hosting a website while pedaling across the world—who would (not) want that? Meet [Jelle Reith], a tinkerer on an epic cycling adventure, whose bicycle doubles as a mobile web server. [Jelle]’s project, jelle.bike, will from the 6th of December on showcase what he’s seeing in real time, powered by ingenuity and his hub dynamo. If you read this far, you’ll probably guess: this hack is done by a Dutchman. You couldn’t be more right.

At the heart of [Jelle]’s setup is a Raspberry Pi 4 in a watertight enclosure. The tiny powerhouse runs off energy generated by a Forumslader V3, a clever AC-to-DC converter optimized for bike dynamos. The Pi gets internet access via [Jelle]’s phone hotspot, but hosting a site over cellular networks isn’t as simple as it sounds. With no static IP available, [Jelle] routes web traffic through a VPS using an SSH tunnel. This crafty solution—expanded upon by Jeff Geerling—ensures seamless access to the site, even overcoming IPv6 quirks.

The system’s efficiency and modularity exemplify maker spirit: harnessing everyday tools to achieve the extraordinary. For more details, including a parts list and schematics, check out [Jelle]’s Hackaday.io project page.

Have you ever dreamt of developing games that run on practically anything, from a modern browser to a microcontroller? Enter WASM-4, a minimalist fantasy console where constraints spark creativity. Unlike intimidating behemoths like Unity, WASM-4’s stripped-back specs challenge you to craft games within its 160×160 pixel display, four color palette, and 64 KB memory. Yes, you’ll curse at times, but as every tinkerer knows, limitations are the ultimate muse.

Born from the WebAssembly ecosystem, this console accepts “cartridges” in .wasm format. Any language that compiles to WebAssembly—be it Rust, Go, or AssemblyScript—can build games for it. The console’s emphasis on portability, with plans for microcontroller support, positions it as a playground for minimalist game developers. Multiplayer support? Check. Retro vibes? Double-check.

Entries from a 2022’s WASM-4 Game Jam showcase this quirky console’s charm. From pixel-perfect platformers to byte-sized RPGs, the creativity is staggering. One standout, “WasmAsteroids,” demonstrated real-time online multiplayer within these confines—proof that you don’t need sprawling engines to achieve cutting-edge design. This isn’t just about coding—it’s about coding smart. WASM-4 forces you to think like a retro engineer while indulging in modern convenience.

WASM-4 is a playground for anyone craving pure, unadulterated experimentation. Whether you’re a seasoned programmer or curious hobbyist, this console has the tools to spark something great.

Chess is timeless, but automating it? That’s where the real magic begins. Enter [Tamerlan Goglichidze]’s Pi Board, an automated chess system that blends modern tech with age-old strategy. Inspired by Harry Potter’s moving chessboard and the commercial Square Off board, [Tamerlan] re-imagines the concept using a Raspberry Pi, stepper motors, and some clever engineering. It’s not just about moving pieces — it’s about doing so with precision and flair.

At its core, the Pi Board employs an XY stepper motor grid coupled with magnets to glide chess pieces across the board. While electromagnets seemed like a promising start, [Tamerlan] found them impractical due to overheating and polarity-switching issues. Enter servo linear actuators: efficient, precise, and perfect for the job.

But the innovation doesn’t stop there. A custom algorithm maps the 8×8 chess grid, allowing motors to track positions dynamically—no tedious resets required. Knight movements and castling? Handled with creative coding that keeps gameplay seamless. [Tamerlan] explains it all in his sleekly designed build log.

Though it hasn’t been long since we featured a Pi-powered LED chess board, we feel that [Tamerlan]’s build stands out for its ingenuity and optimization. For those still curious, we have a treasure trove of over fifty chess-themed articles from the last decade. So snuggle up during these cold winter months and read up on these evergreens!

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.