2025 Hackaday Component Abuse Challenge: Let The Games Begin!

September 16, 2025 by No comments

In theory, all parts are ideal and do just exactly what they say on the box. In practice, everything has its limits, most components have non-ideal characteristics, and you can even turn most parts’ functionality upside down.

The Component Abuse Challenge celebrates the use of LEDs as photosensors, capacitors as microphones, and resistors as heat sources. If you’re using parts for purposes that simply aren’t on the label, or getting away with pushing them to their absolute maximum ratings or beyond, this is the contest for you.

If you committed these sins against engineering out of need, DigiKey wants to help you out. They’re probably got the right part, and they’re providing us with three $150 gift certificates to give out to the top projects. (If you’re hacking just for fun, well, you’re still in the running.)

This is the contest where the number one rule is that you must break the rules, and the project has to work anyway. You’ve got eight weeks, until Nov 11th. Open up a project over at Hackaday.io, pull down the menu to enter in the contest, and let the parts know no mercy!

Honorable Mention Categories:

We’ve come up with a few honorable mention categories to get your ideas flowing. You don’t have to fit into one of these boxes to enter, but we’ll be picking our favorites in these four categories for a shout-out when we reveal the winners.

  • Bizarro World: There is a duality in almost every component out there. Speakers are microphones, LEDs are light sensors, and peltier coolers generate electricity. Turn the parts upside down and show us what they can do.
  • Side Effects: Most of the time, you’re sad when a part’s spec varies with temperature. Turn those lemons into lemonade, or better yet, thermometers.
  • Out of Spec: How hard can you push that MOSFET before it lets go of the magic smoke? Show us your project dancing on the edge of the abyss and surviving.
  • Junk Box Substitutions: What you really needed was an igniter coil. You used an eighth-watt resistor, and got it hot enough to catch the rocket motor on fire. Share your parts-swapping exploits with us.

Inspiration

Diodes can do nearly anything.  Their forward voltage varies with temperature, making them excellent thermometers. Even the humble LED can both glow and tell you how hot it is. And don’t get us started on the photo-diode. They are not just photocells, but radiation detectors.

Here’s a trick to double the current that a 555 timer can sink. We’d love to see other cases of 555 abuse, of course, but any other IC is fair game.

Resistors get hot. Thermochromic paint changes color with temperature. Every five years or so, we see an awesome new design. This ancient clock of [Sprite_tm]’s lays the foundation, [Daniel Valuch] takes it into the matrix, and [anneosaur] uses the effect to brighten our days.

Of course, thin traces can also be resistors, and resistors can get really hot. Check out [Carl Bujega]’s self-soldering four-layer PCB. And while magnetism is nearly magic, a broken inductor can still be put to good use as a bike chain sensor.

Or maybe you have a new twist on the absolutely classic LEDs-as-light-sensors? Just because it’s been done since the early says of [Forrest Mims] doesn’t mean we don’t want to see your take.

Get out there and show us how you can do it wrong too.

2025 Hackaday Component Abuse Challenge

This Rail Speeder Needs A Little Work

September 16, 2025 by 8 Comments

If you take the wheels off a FIAT Punto, you might just notice that those rims fit nicely on a rail. [AT Lab] did, and the resulting build makes for a very watchable video.

Some of us have been known to spend a little too much time chasing trains, and there’s little on rails that won’t catch a railfan’s eye. That goes for rail speeders too, home constructed railcarts for exploring abandoned lines, and there are some great builds out there. We like the one in the video below the break, but we can’t help noticing a flaw which might just curtail its career.

It’s a simple enough build, a wooden chassis, a single motor and chain drive to one axle. All the wheel fittings are 3D printed, which might be a case of using the one tool you have to do everything, but seems to work. It rides well on the test track which appears to be an abandoned industrial siding, but it’s in those wheels we can see the problem and we guess that perhaps the builder is not familiar with rails. The Punto wheels have an inner rim and an outer rim, while a true rail wheel only has an inner one. There’s a good reason for this; real railways have points and other trackwork, not to mention recessed rails at road crossings or the like. We love the cart, but we’d cut those inner rims off to avoid painful derailments.

If you’re up for the ultimate railway build, take care not to go near a live line, and make sure you follow this video series.

Continue reading “This Rail Speeder Needs A Little Work” →

Street with polluted smoggy air

Serious Chemical Threat Sniffer On A Budget

September 16, 2025 by 33 Comments

Chemical warfare detection was never supposed to be a hobbyist project. Yet here we are: Air Quality Guardian by [debdoot], the self-proclaimed world’s first open source chemical threat detection system, claims to pack lab-grade sensing into an ESP32-based build for less than $100. Compare that with $10,000+ black-box hardware and you see why this is worth trying at home, even if this project might not have the nut cracked just yet.

Unlike your air monitor from IKEA, the device aims to analyze raw gas sensor resistance – ohm-level data most devices throw away – combined with temporal spikes, humidity correlations, and a database of 35+ signatures. Of course, there is a lot of work to be done here on the calibration side, and we don’t have any chemical warfare agents on hand to test against, so we have no idea how well it works, and we’d expect false positives. Still, the idea of taking a more granular look at the data coming off the sensor may bear some fruit.

(Editor’s note: edited with a hefty dash of skeptical salt.)

Featured Image by Arjun Lama on Unsplash

Jointly Is A Typeface Designed For CNC Joinery

September 16, 2025 by 9 Comments

If you have a CNC router, you know you can engrave just about any text with the right tool, but Jointly is a typeface that isn’t meant to be engraved. That would be too easy for [CobyUnger]. His typeface “Jointly” is the first we’ve seen that’s meant to be used as joinery.

The idea is simple: carve mortises that take the shape of letters in one piece, and carve matching letter-tenons into the end of another. Push them together, and voila: a joint! To get this concept to work reliably, the font did have to be specially designed — both the inner and outer contours need to be accessible to a rotary cutting tool. Cutting tools get harder to use the smaller they go (or more fragile, at any rate) so with Jointly, the design spec was that any letters over 3/4″ (19.05 mm) tall needed to be handled with a 1/8″ (3.175 mm) rotary cutter.

This gives the font a friendly curved appearance we find quite fetching. Of course if you’re going to be cutting tenons into the end of a board, you’re going to need either some serious z-depth or an interesting jig to get the end of the board under the cutting head. It looks like [CobyUnger] has both, but he mentions the possibility of using a handheld CNC router as the cheaper option.

Speaking of routing out type, do you know the story of Gorton? You can’t make joinery with that typeface, but you’ve almost certainly seen it.

Photo of Microtronic 2090

The Microtronic Phoenix Computer System

September 15, 2025 by No comments

A team of hackers, [Jason T. Jacques], [Decle], and [Michael A. Wessel], have collaborated to deliver the Microtronic Phoenix Computer System.

In 1981 the Busch 2090 Microtronic Computer System was released. It had a 4-bit Texas Instruments TMS1600 microcontroller, ran at 500 kHz, and had 576 bytes of RAM and 4,096 bytes of ROM. The Microtronic Phoenix computer system is a Microtronic emulator. It can run the original firmware from 1981.

Between them the team members developed the firmware ROM dumping technology, created a TMS1xxx disassembler and emulator, prototyped the hardware, developed an Arduino-based re-implementation of the Microtronic, designed the PCB, and integrated the software.

Unlike previous hardware emulators, the Phoenix emulator is the first emulator that is not only a re-implementation of the Microtronic, but actually runs the original TMS1600 firmware. This wasn’t possible until the team could successfully dump the original ROM, an activity that proved challenging, but they got there in the end! If you’re interested in the gory technical details those are here: Disassembling the Microtronic 2090, and here: Microtronic Firmware ROM Archaeology. Continue reading “The Microtronic Phoenix Computer System” →

See Voyager’s 1990 ‘Solar System Family Portrait’ Debut

September 15, 2025 by 3 Comments

It’s been just over 48 years since Voyager 1 was launched on September 5, 1977 from Cape Canaveral, originally to study our Solar System’s planets. Voyager 1 would explore Jupiter and Saturn, while its twin Voyager 2 took a slightly different route to ogle other planets. This primary mission for both spacecraft completed in early 1990, with NASA holding a press conference on this momentous achievement.

To celebrate the 48th year of the ongoing missions of Voyager 1 and its twin, NASA JPL is sharing an archive video of this press conference. This was the press conference where Carl Sagan referenced the pinpricks of light visible in some images, including Earth’s Pale Blue Dot, which later would become the essay about this seemingly insignificant pinprick of light being the cradle and so far sole hope for the entirety of human civilization.

For most people in attendance at this press conference in June of 1990 it would likely have seemed preposterous to imagine both spacecraft now nearing their half-century of active service in their post-extended Interstellar Mission. With some luck both spacecraft will soon celebrate their 50th launch day, before they will quietly sail on amidst the stars by next decade as a true testament to every engineer and operator on arguably humanity’s most significant achievement in space.

Thanks to [Mark Stevens] for the tip.

Continue reading “See Voyager’s 1990 ‘Solar System Family Portrait’ Debut” →

A Closer Look Inside A Robot’s Typewriter-Inspired Mouth

September 15, 2025 by 17 Comments

[Ancient] has a video showing off a fascinating piece of work: a lip-syncing robot whose animated electro-mechanical mouth works like an IBM Selectric typewriter. The mouth rapidly flips between different phonetic positions, creating the appearance of moving lips and mouth. This rapid and high-precision movement is the product of a carefully-planned and executed build. When we featured this project before, we wanted to see under the hood. Now we can.

Behind the face is a ball that, when moving quickly enough, gives the impression of animated mouth and lips. The new video gives a closer look at how it works.

[Ancient] dubs the concept Selectramatronics, because its action is reminiscent of the IBM Selectric typewriter. Instead of each key having a letter on a long arm that would swing up and stamp an ink ribbon, the Selectric used a roughly spherical unit – called a typeball – with letters sticking out of it like a spiky ball.

Hitting the ‘A’ key would rapidly turn the typeball so that the ‘A’ faced forward, then satisfyingly smack it into the ink ribbon at great speed. Here’s a look at how that system worked, by way of designing DIY typeballs from scratch. In this robot, the same concept is used to rapidly flip a ball bristling with lip positions.

We first saw this unusual and fascinating design when its creator showed videos of the end result on social media, pronouncing it complete. We’re delighted to see that there’s now an in-depth look at the internals in the form of a new video (the first link in this post, also embedded below just under the page break.)

The new video is wonderfully wordless, preferring to show rather than tell. It goes all the way from introducing the basic concept to showing off the final product, lip-syncing to audio from an embedded Raspberry Pi.

Continue reading “A Closer Look Inside A Robot’s Typewriter-Inspired Mouth” →