door spring

Compliant Contacts: Hacking Door Locks With Pen Springs

August 11, 2025 by 12 Comments

As you may have guessed given our name, we do love hacks around here, and this one is a great example of making some common, everyday things work in uncommon ways. [Nathan] sent in his hack to detect the door lock position in his basement.

Having a house that dates back to the 1890s, much of it was not very conducive to using off-the-shelf home automation devices. [Nathan] wanted a way to check the status of the basement deadbolt. He went about putting together a custom sensor using some spare parts, including a spare BeagleBone Black. Going full MacGyver, [Nathan] used springs from a ballpoint pen to craft a compliant contact for his sensor.

The pair of springs sat in the door frame and came in contact with the deadbolt; given they are springs, the exact position of the sensor was not very sensitive, as if too close it would just compress the springs slightly more. The springs were wired to the BeagleBone Black’s GPIO, acting as a switch to sense when there was conductivity between the springs through the deadbolt.

This wasn’t just a plug-it-in-and-it-works type of project, mind you; the BeagleBone Black was over 15 ft away from the sensors, lending plenty of opportunity for noise to be introduced into the lines. To combat this, [Nathan] created an RC filter to filter out all the high-frequency noise picked up by his sensor. Following the RC filter, he added in some code to handle the debounce of the sensor, as the springs have some inherent noise in them. Thanks [Nathan] for sending in your resourceful hack; we love seeing the resourcefulness of reusing things already on hand for other purposes. Be sure to check out some of the other repurposed components we’ve featured.

Building A Trash Can Reverb

August 11, 2025 by 6 Comments

These days, if you want a reverb effect, you just dial up whatever software plugin most appeals to you and turn the dials to taste. However, [Something Physical] specialises in… physical things… and thus built a reverb the old fashioned way. Using a trashcan, of course.

The concept is simple enough—the method of operation is exactly the same as any old plate reverb. Audio is played through a speaker connected to the plate (or trashcan), causing it to vibrate. The sound is then picked up at another point on the plate (or trashcan) with some kind of microphonic pickups, amplified, and there you have your reverb signal.

Given it’s built around a piece of street furniture, [Something Physical] has dubbed this the Street-Verb. It uses a class D amp to drive a speaker with a bolt stuck to it. The bolt is then put in contact with the trashcan itself to transfer the vibration. A pair of piezo elements are used as the pickups, run through a preamps built with a humble BC109C transistor. Since there are two pickups, the Street-Verb is effectively a stereo reverb unit, though the input is only mono. [Something Physical] set up the speaker driver and pickups to be easily movable, and was able to test the device with all kinds of street furniture, like gates and street signs, but the trashcan ‘verb setup is by far the most compelling.

We’ve featured other plate reverb builds before, too, albeit less garbage-themed. Video after the break.

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Neon Bulbs? They’re A Gas!

August 11, 2025 by 39 Comments

When you think of neon, you might think of neon signs or the tenth element, a noble gas. But there was a time when neon bulbs like the venerable NE-2 were the 555 of their day, with a seemingly endless number of clever circuits. What made this little device so versatile? And why do we see so few of them today?

Neon’s brilliant glow was noted when William Ramsay and Morris Travers discovered it in 1898. It would be 1910 before a practical lighting device using neon appeared. It was 1915 when the developer, Georges Claude, of Air Liquide fame, received a patent on the unique electrodes suitable for lighting and, thus, had a monopoly on the technology he sold through his company Claude Neon Lights.

However, Daniel Moore in 1917 developed a different kind of neon bulb while working for General Electric. These bulbs used coronal discharge to produce a red glow or, with argon, a blue glow. This was different enough to earn another patent, and neon bulbs found use primarily as indicator lamps before the advent of the LED. However, it would also find many other uses.

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End Of The Eternal September, As AOL Discontinues Dial-Up

August 11, 2025 by 38 Comments

If you used the internet at home a couple of decades or more ago, you’ll know the characteristic sound of a modem  connecting to its dial-up server. That noise is a thing of the past, as we long ago moved to fibre, DSL, or wireless providers that are always on. It’s a surprise then to read that AOL are discontinuing their dial-up service at the end of September this year, in part for the reminder that AOL are still a thing, and for the surprise that in 2025 they still operate a dial-up service.

There was a brief period in which instead of going online via the internet itself, the masses were offered online services through walled gardens of corporate content. Companies such as AOL and Compuserve bombarded consumers with floppies and CD-ROMs containing their software, and even Microsoft dipped a toe in the market with the original MSN service before famously pivoting the whole organisation in favour of the internet in mid 1995. Compuserve was absorbed by AOL, which morphed into the most popular consumer dial-up ISP over the rest of that decade. The dotcom boom saw them snapped up for an exorbitant price by Time Warner, only for the expected bonanza to never arrive, and by 2023 the AOL name was dropped from the parent company’s letterhead. Over the next decade it dwindled into something of an irrelevance, and is now owned by Yahoo! as a content and email portal. This dial-up service seems to have been the last gasp of its role as an ISP.

So the eternal September, so-called because the arrival of AOL users on Usenet felt like an everlasting version of the moment a fresh cadre of undergrads arrived in September, may at least in an AOL sense, finally be over. If you’re one of the estimated 0.2% of Americans still using a dial-up connection don’t despair, because there are a few other ISPs still (just) serving your needs.

Smartphone Hackability, Or, A Pocket Computer That Isn’t

August 11, 2025 by 86 Comments

Smartphones boggle my mind a whole lot – they’re pocket computers, with heaps of power to spare, and yet they feel like the furthest from it. As far as personal computers go, smartphones are surprisingly user-hostile.

In the last year’s time, even my YouTube recommendations are full of people, mostly millennials, talking about technology these days being uninspiring. In many of those videos, people will talk about phones and the ecosystems that they create, and even if they mostly talk about the symptoms rather than root causes, the overall mood is pretty clear – tech got bland, even the kinds of pocket tech you’d consider marvellous in abstract. It goes deeper than cell phones all looking alike, though. They all behave alike, to our detriment.

A thought-provoking exercise is to try to compare smartphone development timelines to those of home PCs, and see just in which ways the timelines diverged, which forces acted upon which aspect of the tech at what points, and how that impacted the alienation people feel when interacting with either of these devices long-term. You’ll see some major trends – lack of standardization through proprietary technology calling the shots, stifling of innovation both knowingly and unknowingly, and finance-first development as opposed to long-term investments.

Let’s start with a fun aspect, and that is hackability. It’s not perceived to be a significant driver of change, but I do believe it to be severely decreasing chances of regular people tinkering with their phones to any amount of success. In other words, if you can’t hack it in small ways, you can’t really make it yours.

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Don’t Say This DIY Diskette Was A Flop

August 11, 2025 by 21 Comments

Sometimes, you build a thing because you need a thing. Sometimes, you do it just to see if you can. This project is in category two: [polymatt] didn’t need to create a floppy disk from scratch-– plenty of old disks still exist– but we’re glad he made the attempt because it makes for a fascinating video that’s embedded below.

Some of you are going to quibble with the terminology [polymatt] uses in this video: first of all, he didn’t begin by creating the universe, so is he really starting “from scratch”? Secondly, the “floppy” format he’s attempting to copy is a 3½” diskette, which does not flop at all.

Choosing newer stiff-walled medium does allow him to practice his CNC skills and make the coolest-looking floppy enclosure we’ve ever seen. (It turns out brushed aluminum is even cooler-looking than the translucent neon ones.) On the other hand, we can’t help but wonder if a lower-density format 5¼” disk might have been an easier hurdle to jump. The diskette that was built does magnetize, but it can’t read or write actual files. We wonder if the older format might have been more forgiving of grain size and composition of his ferrite coating. Even more forgiving still would be to use these techniques to make magnetic tape  which is a perfectly viable way to store data.

Instead of storing data, you could make your own cleaning floppy. It’s not like data storage was really the point here, anyway– its not the destination, but the journey. So whatever you call this DIY diskette, please don’t call it a flop.

Thanks to [Anonymous] for the great tip!

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The Trials Of Trying To Build An Automatic Filament Changer

August 11, 2025 by 16 Comments

Running out of filament mid-print is a surefire way to ruin your parts and waste a lot of time. [LayerLab] was sick of having this problem, and so sought to find a proper solution. Unfortunately, between off-the-shelf solutions and homebrew attempts, he was unable to solve the problem to his satisfaction.

[LayerLab] had a simple desire. He wanted his printer to swap to a second spool of filament when the first one runs out, without ruining or otherwise marring the print. It sounds simple, but the reality is more complicated. As an Australian, he couldn’t access anything from InfinityFlow, so he first attempted to use the “auto refill” features included on the Bambu Labs AMS 2. However, it would routinely make filament changes in outside wall areas of a print, leaving unsightly marks and producing poorer quality parts.

His next effort was to use the Wisepro Auto Refill Filament Buffer. It’s a feeder device that takes filament from two spools, and starts feeding the backup spool in to your printer when the primary spool runs out. Unfortunately, [LayerLab] had a cavalcade of issues with the device. It would routinely feed from the secondary spool when there was still primary filament available, jamming the device, and it didn’t come with a proper mounting solution to work with consumer printers. It also had bearings popping out the top of the housing. Attempts to rework the device into a larger twin-spool rig helped somewhat, but ultimately the unreliability of the Wisepro when changing from one spool to another meant it wasn’t fit for purpose. Its feeder motors were also to trigger the filament snag cutters that [LayerLab] had included in his design.

Ultimately, the problem remains unsolved for [LayerLab]. They learned a lot along the way, mostly about what not to do, but they’re still hunting for a viable automatic filament changer solution that suits their needs. Filament sensors help, but can only do so much. If you reckon you know the answer, or a good way forward, share your thoughts in the comments. Video after the break.

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