2025 Component Abuse Challenge: Load Cell Anemometer

October 9, 2025 by 22 Comments

When you think anemometer, you probably don’t think “load cell” — but (statistically speaking) you probably don’t live in Hurricane Country, which is hard on wind-speed-measuring-whirligigs. When [BLANCHARD Jordan] got tired of replacing professionally-made meteorological eggbeaters, he decided he needed something without moving parts. Whatever he came up with would probably qualify for the Component Abuse Challenge, but the choice of load cells of all things to measure wind speed? Yeah, that’s not what the manufacturer intended them for.

In retrospect, it’s actually a fairly obvious solution: take a plate of known area, and you’re going to get a specific force at a given air speed. The math isn’t hard, it’s just not how we normally see this particular measurement done. Of course, a single plate would have to be pivoted to face the wind for an accurate reading, which means moving parts– something specifically excluded from the design brief. [Jordan] instead uses a pair of load cells, mounted 90 degrees to one another, for his anemometer. One measures the force in a north-south axis, and the other east-west, allowing him to easily calculate both wind speed and direction. In theory, that is. Unfortunately, he vibe coded the math with ChatGPT, and it looks like it doesn’t track direction all that well. The vibe code runs on an ESP32 is responsible for polling data, tossing outliers, and zeroing out the load cells on the regular.

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Colorful parachutes at different levels of expansion

Holy Parachute Out Of Kirigami

October 9, 2025 by 14 Comments

If you have a fear of heights and find yourself falling out of an airplane, you probably don’t want to look up to find your parachute full of holes. However, if the designer took inspiration from kirigami in the same way researchers have, you may be in better shape than you would think. This is because properly designed kirigami can function as a simple and effective parachute.

Kirigami, for those unfamiliar, is a cousin of origami where, instead of folding, you cut slits into paper. In this case, the paper effectively folds itself after being dropped, which allows the structure to create drag in ways similar to traditional parachute designs. Importantly, however, the stereotypical designs of parachutes have some more severe drawbacks than they appear. Some major issues include more obvious things, such as having to fold and unpack before and after dropping. What may be less obvious are the large eddies that traditional parachutes create or their ease at being disturbed by the surrounding wind.

The kirigami chutes fix these issues while being easier to manufacture and apply. While these are not likely to be quite as effective for human skydiving, more durable applications may benefit. Quoted applications, including drone delivery or disaster relief, worry more about accuracy and scalability rather than the fragile bones of its passenger.

Clever and simple designs are always fun to try to apply to your own projects, so if you want to have your own hand, make sure to check out the paper itself here. For those more interested in clever drone design to take inspiration from, look no further than this maple seed-inspired drone.

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Meshtastic: A Tale Of Two Cities

October 9, 2025 by 65 Comments

If I’m honest with myself, I don’t really need access to an off-grid, fault-tolerant, mesh network like Meshtastic. The weather here in New Jersey isn’t quite so dynamic that there’s any great chance the local infrastructure will be knocked offline, and while I do value my privacy as much as any other self-respecting hacker, there’s nothing in my chats that’s sensitive enough that it needs to be done off the Internet.

But damn it, do I want it. The idea that everyday citizens of all walks of life are organizing and building out their own communications network with DIY hardware and open source software is incredibly exciting to me. It’s like the best parts of a cyberpunk novel, without all the cybernetic implants, pollution, and over-reaching megacorps. Well, we’ve got those last two, but you know what I mean.

Meshtastic maps are never exhaustive, but this gives an idea of node density in Philly versus surrounding area.

Even though I found the Meshtastic concept appealing, my seemingly infinite backlog of projects kept me from getting involved until relatively recently. It wasn’t until I got my hands on the Hacker Pager that my passing interest turned into a full blown obsession. But it’s perhaps not for the reason you might think. Traveling around to different East Coast events with the device in my bag, it would happily chirp away when within range of Philadelphia or New York, but then fall silent again once I got home. While I’d get the occasional notification of a nearby node, my area had nothing like the robust and active mesh networks found in those cities.

Well, they say you should be the change you want to see in the world, so I decided to do something about it. Obviously I wouldn’t be able to build up an entire network by myself, but I figured that if I started standing up some nodes, others might notice and follow suit. It was around this time that Seeed Studio introduced the SenseCAP Solar node, which looked like a good way to get started. So I bought two of them with the idea of putting one on my house and the other on my parent’s place down the shore.

The results weren’t quite what I expected, but it’s certainly been an interesting experience so far, and today I’m even more eager to build up the mesh than I was in the beginning.

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Google Japan Turn Out Another Keyboard, And It’s A Dial

October 9, 2025 by 20 Comments

There’s a joke that does the rounds, about a teenager being given a dial phone and being unable to make head nor tail of it.  Whether or not it’s true, we’re guessing that the same teen might be just a stumped by this year’s keyboard oddity from Google Japan. It replaces keys with a series of dials that work in the same way as the telephone dial of old. Could you dial your way through typing?

All the files to make the board, as well as a build guide, are in the GitHub repository linked above, but they’ve also released a promotional video that we’ve put below the break. The dials use 3D printed parts, and a rotary encoder to detect the key in question. We remember from back in the day how there were speed dialing techniques with dial phones, something we’ve probably by now lost the muscle memory for.

We like this board for its quirkiness, and while it might become a little tedious to type a Hackaday piece on it, there might be some entertainment for old-timers in watching the youngsters figuring it out. If you’re hungry for more, we’ve covered them before.

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Billy Bass Gets New Job As A Voice Assistant

October 9, 2025 by 8 Comments

For those who were alive and conscious before the modern Internet, there were in fact things that went “viral” and became cultural phenomenon for one reason or another. Although they didn’t spread as quickly or become forgotten as fast, things like Beanie Babies or greeting a friend with an exaggerated “Whassup?” could all be considered viral hits of the pre-Internet era.

Another offline hit from the late 90s was the Billy Bass, an absurdist bit of physical comedy in the form of a talking, taxidermied fish. At the time it could only come to life and say a few canned lines, but with the help of modern hardware it can take on a whole new life.

This project comes to us from [Cian] who gutted the fish’s hardware to turn it into a smart voice assistant with some modern components, starting with an ESP32 S3. This chip has enough power to detect custom “wake words” to turn on the fish assistant as well as pass the conversation logic to and from a more powerful computer, handle the audio input and output, and control the fish’s head and tail motors. These motors, as well as the speaker, are the only original components remaining. The new hardware, including an amplifier for the speaker, are mounted on a custom 3D printed backplate.

After some testing and troubleshooting, the augmented Billy was ready to listen for commands and converse with the user in much the same way as an Alexa or other home assistant would. [Cian] built this to work with Home Assistant though, so it’s much more open and easier to recreate for anyone who still has one of these pieces of 90s kitch in a box somewhere.

Perhaps unsurprisingly, these talking fish have been the basis of plenty of hacks over the years since their original release like this one from a few years ago that improves its singing ability or this one from 2005 that brings Linux to one.

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Why Stepper Motors Still Dominate 3D Printing

October 8, 2025 by 39 Comments

It’s little secret that stepper motors are everywhere in FDM 3D printers, but there’s no real reason why you cannot take another type of DC motor like a brushless DC (BLDC) motor and use that instead. Interestingly, some printer manufacturers are now using BLDCs for places where the reduction in weight matters, such as in the tool head or extruder, but if a BLDC can be ‘stepped’ much like any stepper motor, then why prefer one over the other? This is the topic of a recent video by [Thomas Sanladerer], with the answer being mostly about cost, and ‘good enough’ solutions.

The referenced driving method of field-oriented control (FOC), which also goes by the name of vector control, is a VFD control method in which the controller can fairly precisely keep position much like a stepper motor, but without the relatively complex construction of a stepper motor. Another advantage is that FOC tends to use less power than alternatives.

Using a FOC controller with a BLDC is demonstrated in the video, which also covers the closed-loop nature of such a configuration, whereas a stepper motor is generally driven in an open-loop fashion. Ultimately the answer at this point is that while stepper motors are ‘good enough’ for tasks where their relatively large size and weight aren’t real issues, as BLDCs with FOC or similar becomes more economical, we may see things change there.

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Where Is Mathematics Going? Large Language Models And Lean Proof Assistant

October 8, 2025 by 29 Comments

If you’re a hacker you may well have a passing interest in math, and if you have an interest in math you might like to hear about the direction of mathematical research. In a talk on this topic [Kevin Buzzard], professor of pure mathematics at Imperial College London, asks the question: Where is Mathematics Going?

It starts by explaining that in 2017 he had a mid-life crisis, of sorts, becoming disillusioned with the way mathematics research was being done, and he started looking to computer science for solutions.

He credits Euclid, as many do, with writing down some axioms and starting mathematics, over 2,000 years ago. From axioms came deductions, and deductions became mathematical facts, and math proceeded in this fashion. This continues to be the way mathematical research is done in mathematical departments around the world. The consequence of this is that mathematics is now incomprehensibly large. Similarly the mathematical proofs themselves are exceedingly large, he gives an example of one proof that is 10,000 pages long and still hasn’t been completely written down after having been announced more than 20 years ago.

The conclusion from this is that mathematics has become so complex that traditional methods of documenting it struggle to cope. He says that a tertiary education in mathematics aims to “get students to the 1940s”, whereas a tertiary education in computer science will expose students to the state of the art.

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