TechyMagThings

As any science YouTuber or first-year physics student is quick to point out, the universe is mostly empty space. Not just space itself, but the amount of “empty” space between nuclei and their electrons is also huge. Getting rid of this empty space results in all kinds of interesting phenomena like degenerate matter and black holes. But the concept can be extrapolated into our daily lives as well; many things are so filled with air that we can get a lot more usable storage space by compressing them down a little bit. [Super Valid Designs] took this concept to a coat closet, building one that can hold an impressive number of coats.

He started by looking at an existing closet, which could hold around 21 coats but only if someone used two hands to cram the coats into the space. After a trip to a store which sells rugs, he saw a much better design that lets all the rugs pivot like the pages on a book, and took this idea to his closet using a similar mechanism designed for storing large blueprints instead of rugs. The closet he built around this mechanism has two hinged doors which allow a person easy access to the coats, and when opened the blueprint hangers pivot out like a book, allowing the coats to not only be easily accessed without disrupting the other coats, but also allow them to be compressed down by the closet door for storage.

For comparison, the original closet could only hold 10 coats when restricted to single-hand operation and 21 when using both. The new closet design is smaller, and can hold 24 coats with a single hand and over 30 when using both, a dramatic improvement of closet efficiency. To top it off, a set of cupboards on top and bottom allow for storing shoes and hats as well, and there’s even a garage for a robotic vacuum cleaner. Surprisingly, we don’t see many closet optimization builds around here. The closest we can come is another traditionally small space, a college dorm.

After the Orion capsule of the Artemis I lunar mission returned to Earth, it was found that massive chunks of its heatshield had been ripped off, posing a serious risk to any future missions. In a recent video in which [polymatt] takes a break from repairing old laptop shells and the like, he tries to recreate the Orion’s heatshield using a variety of methods and materials.

For this test a number of samples were created, each using the same kind of segmented structure as the larger Orion heatshield. The filler was created from the published materials for the heat shield by NASA, requiring just serious mixing.

The resulting samples were then cured with thermocouples inserted, before they got blasted with the heat from a propane torch, trying to simulate the various re-entry patterns.

Perhaps unsurprisingly, the results matched the findings by NASA for why the Orion’s heat shield had failed, being the build-up of gases due to the sustained pyrolysis processes that eventually fractured the material. Despite some experimental flaws that injected residual heat from the copper structure, this still seems to be a pretty good setup to test ablative heat shields in DIY lab conditions.

We try to steer clear of politics and societal issues here at Hackaday, so a protest is not usually the sort of thing we’d cover. But we figure it’s safe enough to bend the rules a bit when the ones doing the protesting happen to be robots.

About 30 bots gathered — or at least were commanded to gather by the event organizers — in Warsaw to spur discussion about the impact AI and robots will have on the labor market. Beyond getting public and media attention, the demonstration was also designed to raise awareness of what modern humanoid robots can do. While we appreciate the idea of showing robots taking the “jobs” of the protesters, it does seem somewhat ironic that marching around and chanting for hours is exactly the sort of repetitive work that most people would be happy to see taken over by machines.

Although we hope these protests remain peaceful, there’s always a chance things can turn violent when tensions are high. Should things go south, take comfort in the knowledge that a company in Japan has introduced a robot ambulance service. It’s probably more accurate to compare it with roadside assistance, as the goal is to repair the robot on-site. That said, if the fault is more serious, they can bring the damaged bot back to HQ. Of course, the major difference between this program and a traditional ambulance service is that they’ll be able to bring along a spare robot that can take over the patient’s job while repairs are being made. Should anyone start doing that for humans, expect a few more protests.

Speaking of repairs, [Boone Ashworth] at WIRED recently wrote up an interesting hands-on experience he had with John Deere’s AI-driven DIY repair service at the company’s corporate headquarters. Armed with a laptop and tasked with fixing the error message showing on a ~$120,000 USD tractor, he was able to follow the instructions provided by the software to identify a sensor that had been unplugged. Reconnecting the sensor fixed the error message and elicited applause from the Deere reps who presumably had carefully unplugged the sensor in the first place for the purposes of the demonstration.

If that doesn’t strike you as a particularly impressive display for a subscription service which starts at $195 a year for each individual machine, you aren’t alone. When Boone reported his experience to critics of Deere’s repairability track record, it was met with literal laughter. You don’t have to have worked in the fields to know that a sensor becoming unplugged ranks pretty low on the list of potential problems you might face in the middle of a harvest.

We can certainly understand why Deere wouldn’t ask journalists to fix a blown clutch or a leaky hydraulic cylinder for the purposes of a media demo. Even so, they could surely have come up with something a bit more challenging if their goal was to convince customers to log into their repair service — something the company claims only about a thousand users do each day.

Finally, this one leans more heavily into the “arts and crafts” than we’d usually cover here on Hackaday, but [Terence Eden]’s Collection of Imaginary Software is too cool not to get a mention.

The idea is simple enough: make up fake disk labels for a bunch of fictional pieces of software (think the games David Lightman was trying to get his hands on in WarGames), stick them on some of the old 3.5 floppies we know you have hiding in a box somewhere, and put them in a frame.

As we’ve talked about in the past, many of us in the hacker and maker community were inspired by nerds in the media. This project strikes us as a fantastic way to show off just which examples you resonated with personally, and if any readers come up with something similar to adorn the walls of their basement, we’d love to see it.

See something interesting that you think would be a good fit for our weekly Links column? Drop us a line; we’d love to hear about it.

It is a classic Hackaday situation. You have an Egret GT E-scooter. It has a screen that shows the usual dash stats, but that led to an annoyance. You could accidentally enter firmware update mode and, from there, enter operational mode without the security PIN. [Ben] couldn’t let that stand, so he reverse-engineered the protocol and rewrote the firmware in Rust. As he put it, “… because I have to break… everything I own…” We get it.

The mobile app was useful for some basic info, since sniffing Bluetooth is fairly easy and analyzing mobile code is, more or less, straightforward. Analysis revealed some data that doesn’t show on the display and that several things are sent back to home base tagged with the scooter’s unique ID — another reason to gut the existing firmware.

Internally, the scooter uses the CAN Bus, so out came the oscilloscope and a homebrew CAN decoder.  Surprisingly, the CAN bus is accessible on the USB-C port’s data pins. Officially, the port is only for charging phones, so you have to wonder what your phone makes of the alien signals on the data pins when it is charging.

Firmware updates actually come in at least three flavors: display, input panel, and main controller. Reverse engineering the firmware update process was crucial to installing the new firmware.

If you own a similar scooter, this post is a goldmine. If you don’t, it is still a very detailed breakdown of a reverse-engineering workflow, and you can apply many of the tools and techniques to your next project.

Of course, another option is to just keep the scooter and replace the brains. If you want to learn more about reverse engineering, there are literally dozens of Hackaday posts to help you get started.

If you’ve never heard of the Spin Semiconductors FP-1 digital signal processor chip, don’t worry– that just means you haven’t been deep into guitar petals and audio effects hardware lately. [adamjvr], a.k.a. [avr] has, and he’s gone to the point of creating a PC-based emulator of this sound chip to simplify development.

If you don’t see the utility, stop and think about the development cycle without a simulation like this: you program, you flash to a board, and you test there. Not only does the ‘flash to the board’ step add time and friction, you do also have a limited number of flashes on the board’s memory. With an emulator on your PC, the workflow tightens to ‘code, test’ and you don’t flash the board until the simulated DSP is doing the sounds you want it to.

As for the FV-1 itself, it’s an interesting little chip in that it’s quite a full-featured DSP– rather, it’s small instruction set is focused entirely on audio effects. If you’re into that world– be it guitar pedals or otherwise– you may find this project very useful. There are releases for Linux, MacOS and Windows, and it’s all open-source on GitHub, under the Mozilla Public License. It’s not the most common choice, but we’re hardly going to complain about licenses to anyone willing to share their hard work.

If you like the idea of testing your work before you go to the bench, we’ve seen software that offer the same functionality for Arduino projects, as well as other AVR and PIC micros. It’s been a while since we featured a programmable guitar pedal, so we hope this tool enables others to rock out.

You want Retro? We did, when we started our retrocomputing challenge. [Peter] decided that transistors weren’t retro enough, and sent us this lovely homebrew relay computer, complete with 16- bit CPU, which is rather more bits than one normally associates with clicky clacky contacts.

The architecture is very simple– it just uses an accumulator register, ACCU, and goes from there. All mathematics and save/load operations go through ACCU. There whole instruction set is only 19 commands, and he’s used that set to program such lovely things as calculating 3 digits of Pi– which only took 8 minutes of glorious clicking. There’s a demo video of that embedded below. [Peter] has even implemented a display by hooking his computer to a 32×32 LED matrix, but don’t expect it to relay updates really quickly.

If this computer looks familiar, it’s because its earlier incarnation was one of the more “extra” entries in last year’s one-hertz challenge, where it was used to blink an indicator lamp. Yes, even relay computers apparently get started with the “blinky” sketch.

If you want in on the fun, our retrocomputer challenge runs until October 27th, so there’s lots of time left to turn back the clock.

Although building a table saw out of LEGO is probably not the first thing that comes to mind when you look at those colorful bits of plastic, [Jamie] has been on a bit of a search for more applications of his LEGO-based air-powered motors. Naturally this led to the idea of doing something useful with it, like making a table saw you can actually use for real wood.

Starting off with a basic prototype using only regular LEGO pieces to get the mechanism figured out, [Jamie] then builds this up into said air-powered table saw featuring an actual metal blade. Suffice it to say that this isn’t something that you want your children to do with their LEGO while unsupervised.

The star of the show is of course the air-powered turbine that spins the blade. This is something that [Jamie] has been working on for a while, going through a number of prototypes to figure out a 3D printed geometry for the turbine blade that helps to convert as much of the high-pressure air into rotation.

Along the way it was also discovered that 3D printing saw blades is pretty hard, probably due to the lack of a sharp edge. This is definitely an area where it’s hard to beat a real table saw blade, with the added caveat that anything that’s good at cutting up boards of wood and sausages will just as happy slice through careless primate fingers.

In terms of safety features, the air supply is cut automatically with a sort of dead-man switch that requires you to keep one hand on it while using the final table saw design. There also an auto-feeding system added that tries to guide the board into the saw, but this turned out to be finicky. Suffice it to say that an air compressor and a handful of non-LEGO-approved components created a pretty convincing table saw.