Blocky tread, yellow hub-- yep, it looks like LEGO

10″ LEGO Tyre Is Practical Nostalgia

September 29, 2025 by Tyler August 6 Comments

If there’s one thing that has come to define the generations after the baby boom, it’s probably nostalgia. It’s heavily marketed and weaponized by the market: yearning for better, simpler times seems to be a core thread of the consumer economy these days. [Makerneer] combined his xilennial love of LEGO bricks with the flat tires on his log splitter to produce a 10″ TPU tyre will never go flat, and provide a dopamine release every time he sees it.

The tyre is a custom model to fit his particular rims, but he does provide STEP and F3D files if you’d like to try modifing it for your own purpose — they’re at Step 6 of the Instructable. Props to [Makerneer] for truly open-sourcing the design instead of just tossing STL files online. His build log also takes the time to point out the ways he had to modify the LEGO tyre profile to make it amenable to 3D printing: notably chamfering some of the tread pattern to eliminate bridging, which is a bit of a no-no with TPU.

As you can see in the (unfortunately vertical) demo video below, it’s a bit quite a bit squishier than a regular run-flat tyre, but that was part of [Makerneer]’s design goal. He didn’t like how rigid the non-pneumatic tyres he’d tried were, so endevoured to design something himself; the whole LEGO thing was just for fun. If you wanted to replicate this tyre with a bit less skoosh, you need only tune the infill on your print.

While only time will tell how long this LEGO-inspired add-on will continue adding whimsy to [Makerneer]’s log-splitting, we have tests to show it will outperform any other plastic he might have printed. This project is probably more practical than a 3D printed bicycle tyre, which doesn’t even have the side benefit of whimsy. Continue reading “10″ LEGO Tyre Is Practical Nostalgia” →

Whither The Chip Shortage?

September 27, 2025 by Elliot Williams 40 Comments

Do you remember the global chip shortage? Somehow it seems so long ago, but it’s not even really been three years yet. Somehow, I had entirely forgotten about it, until two random mentions about it popped up in short succession, and brought it all flooding back like a repressed bad dream.

Playing the role of the ghost-of-chip-shortage-past was a module for a pair of FPV goggles. There are three versions of the firmware available for download at the manufacturer’s website, and I had to figure out which I needed. I knew it wasn’t V1, because that was the buggy receiver PCB that I had just ordered the replacement for. So it was V2 or V3, but which?

Digging into it, V2 was the version that fixed the bug, and V3 was the redesign around a different microcontroller chip, because they couldn’t get the V2 one during the chip shortage.

I saw visions of desperate hackers learning new toolchains, searching for alternative parts, finding that they could get that one chip, but that there were only 20 of them left and they were selling for $30 instead of $1.30. I know a lot of you out there were designing through these tough couple years, and you’ve all probably got war stories.

And yet here we are, definitively post-chip-shortage. How can you be sure? A $30 vape pen includes a processor that we would have killed for just three years ago. The vape includes a touchscreen, just because. And it even has a Bluetooth LE chip that it’s not even using. My guess is that the hardware designers just put it in there hoping that the firmware team would get around to using it for something.

This vape has 16 MB of external SPI Flash! During the chip shortage, we couldn’t even get 4 MB SPI flash.

It’s nice to be on the other side of the chip shortage. Just order whatever parts you want and you get them, but don’t take for granted how luxurious that feels. Breathe easy, and design confidently. You can finally use that last genuine STM32F103 blue pill board without fear of it being the last one on earth.

(Featured image is not an actual photo of the author, although he does sometimes have that energy.)

Play Capacitor Cupid With The Matchmaker

September 23, 2025 by Donald Papp 5 Comments

Occasionally a design requires capacitors that are much closer to being identical in value to one another than the usual tolerance ranges afford. Precision matching of components from parts on hand might sound like a needle-in-a-haystack problem, but not with [Stephen Woodward]’s Capacitor Matchmaker design.

The larger the output voltage, the greater the mismatch between capacitors A and B.

The Matchmaker is a small circuit intended to be attached to a DVM, with the output voltage indicating whether two capacitors (A and B) are precisely matched in value. If they are not equal, the voltage output indicates the degree of the mismatch as well as which is the larger of the two.

The core of the design is complementary excitation of the two capacitors (the CD4013B dual flip-flop achieves this) which results in a measurable signal if the two capacitors are different; nominally 50 mV per % of mismatch. Output polarity indicates which of the capacitors is the larger one. In the case of the two capacitors being equal, the charges cancel out.

Can’t precision-matched capacitors be purchased? Absolutely, but doing so is not always an option. As [Stephen] points out, selection of such components is limited and they come at an added cost. If one’s design requires extra-tight tolerances, requires capacitor values or types not easily available as precision pairs, or one’s budget simply doesn’t allow for the added cost, then the DIY approach makes a lot more sense.

If you’re going to go down this road, [Stephen] shares an extra time-saving tip: use insulated gloves to handle the capacitors being tested. Heating up a capacitor before testing it — even just from one’s fingers — can have a measurable effect.

[Stephen]’s got a knack for insightful electronic applications. Check out his PWMPot, a simple DIY circuit that can be an awfully good stand-in for a digital potentiometer.

It’s A Variable Capacitor, But Not As We Know It

September 17, 2025 by Jenny List 22 Comments

Radio experimenters often need a variable capacitor to tune their circuits, as the saying goes, for maximum smoke. In decades past these were readily available from almost any scrap radio, but the varicap diode and then the PLL have removed the need for them in consumer electronics. There have been various attempts at building variable capacitors, and here’s [radiofun232] with a novel approach.

A traditional tuning capacitor has a set of meshed semicircular plates that have more of their surface facing each other depending on how far their shaft is turned. The capacitor presented in the first video below has two plates joined by a hinge in a similar manner to the covers of a book. It’s made of tinplate, and the plates can be opened or closed by means of a screw.

The result is a capacitor with a range from 50 to 150 picofarads, and in the second video we can see it used with a simple transistor oscillator to make a variable frequency oscillator. This can form the basis of a simple direct conversion receiver.

We like this device, it’s simple and a bit rough and ready, but it’s a very effective. If you’d like to see another unusual take on a variable capacitor, take a look at this one using drinks cans.

Continue reading “It’s A Variable Capacitor, But Not As We Know It” →

A photo of the air-wired circuit, with one LED on and the other off.

The Magic Of The Hall Effect Sensor

September 9, 2025 by John Elliot V 23 Comments

Recently, [Solder Hub] put together a brief video that demonstrates the basics of a Hall Effect sensor — in this case, one salvaged from an old CPU fan. Two LEDs, a 100 ohm resistor, and a 3.7 volt battery are soldered onto a four pin Hall effect sensor which can toggle one of two lights in response to the polarity of a nearby magnet.

If you’re interested in the physics, the once sentence version goes something like this: the Hall Effect is the production of a potential difference, across an electrical conductor, that is transverse to an electric current in the conductor and to an applied magnetic field perpendicular to the current. Get your head around that!

Of course we’ve covered the Hall effect here on Hackaday before, indeed, our search returned more than 1,000 results! You can stick your toe in with posts such as A Simple 6DOF Hall Effect ‘Space’ Mouse and Tracing In 2D And 3D With Hall Effect Sensors.

Continue reading “The Magic Of The Hall Effect Sensor” →

Give Your Twist Connections Some Strength

September 9, 2025 by Jenny List 44 Comments

We’ve all done it at some time — made an electrical connection by twisting together the bare ends of some wires. It’s quick, and easy, but because of how little force required to part it, not terribly reliable. This is why electrical connectors from terminal blocks to crimp connectors and everything else in between exist, to make a more robust join.

But what if there was a way to make your twist connections stronger? [Ibanis Sorenzo] may have the answer, in the form of an ingenious 3D printed clamp system to hold everything in place. It’s claimed to result in a join stronger than the wire itself.

The operation is simple enough, a spring clamp encloses the join, and a threaded outer piece screws over it to clamp it all together. There’s a pair of 3D printable tools to aid assembly, and a range of different sizes to fit different wires. It looks well-thought-out and practical, so perhaps it could be a useful tool in your armoury. We can see in particular that for those moments when you don’t have the right connectors to hand, a quick 3D print could save the say.

A few years ago we evaluated a set of different ways to make crimp connections. It would be interesting to subject this connection to a similar test. Meanwhile you can see a comprehensive description in the video below the break.

Continue reading “Give Your Twist Connections Some Strength” →

Turning A $2 IKEA Lantern Into A Stylish Enclosure

September 9, 2025 by Fenix Guthrie 35 Comments

It’s fair to say that the average Hackaday reader enjoys putting together custom electronics. Some of those builds will be spaghetti on a breadboard, but at some point you’ll probably have a project that needs a permanent case. If you’re looking for a small case for your latest creation, check out [Julius Curt’s] modification of an IKEA Vårsyren lantern into a customizable enclosure!

Continue reading “Turning A $2 IKEA Lantern Into A Stylish Enclosure” →