Introducing The Garlic-Powered Door And Window Sensor

Most home security sensors require a chemical battery or external power source to operate, which can be a point of weakness. If the battery in a window or door sensor dies overnight and nobody is there to swap it, it might miss that one intruder or mess up your carefully curated home automation system. In that sense self-powered sensors are rather interesting, such as this one by [Manas Tiwari] and [Deepak Bharti] that is based around the triboelectric effect.

The research article is sadly paywalled, but the IEEE Spectrum article covers all the salient details. The sensor uses ground up garlic peel for the positive side of this triboelectric nanogenerator (TENG) as they call it, with a sheet of polyethylene (PE) forming the negative side. Once installed on a door frame, opening said door generates about 210 VAC with a 45 µA short circuit current. A dual-side layer of garlic peel bumps this up to 400 VAC and 65 µA.

As installed, the researchers used this generated current to detect changes using a separate MCU running off a powerbank, which obviously does not really solve the ‘running out of charge’ issue. The generated power could conceivably be used to send a brief wireless packet to a receiver elsewhere in the room, somewhat like the Bluetooth link in the example, but more low-power.

The researchers also reported that this sensor was still functional after half a year in storage, and survived 200 stress cycles, which seems like a good start for what appears to be a very cheap sensor to construct.

Turning A Run-Over Samsung Galaxy S23 Into A Gaming PC

Repurposing old smartphones for more general purpose computing isn’t a new thing, but the project by [LastComputer] ups the ante by going from a Samsung Galaxy S23 that looks like it got run over by at least a few cars to a very serviceable gaming computer, courtesy of its Snapdragon 8 Gen 2 SoC.

The somehow still working but definitely worse for wear phone was purchased for 1,700 Ukrainian Hryvnia (~$40). It being SIM locked also helped reduce the price, even if someone had somehow wanted to use it again as a phone. Since the SoC inside is also used in quite capable gaming handhelds, but with good cooling, that would be a real waste.

Converting it into proper gaming system requires some careful disassembly, some gentle whacking with a hammer to straighten out the frame and a new battery as the mainboard won’t work without one installed.

A 3D-printed phone case glued to an SSD cage for the 512 GB SSD serves as the enclosure, along with two USB hubs, one of which also provides HDMI output. For the active cooling system a heatsink was hot-glued to the vapor chamber with a properly sized fan mounted to it. Here we could definitely see some zip ties being added to prevent it from falling off.

Compared to running the phone in its stock cooling configuration this shaves off about seven degrees C, with thermal throttling noticeably reduced. This consequently provides a much better desktop experience in Samsung’s DeX (Desktop eXperience) desktop mode, which is what’s used for running applications and games.

Running God of War as an emulated PS2 game works pretty well, as does running games with the Dolphin emulator and the GameHub app using which PC games on Steam, GoG and others can be run. Although you can also install other OSes on the phone hardware, Samsung DeX doesn’t appear to be a bad option if you happen to repurpose a high-end Samsung phone that supports this mode.

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The 80s Called: They Say This DIY Phone Is, Like, Totally Rad

Like more than a few of us , [Kevin Noki] is sick of being pulled out of flow state by that annoyingly addictive black rectangle we all carry around. His solution was to build a phone to escape his phone, in a YouTube video we embedded down below. We’d say that phone is straight out of the 1980s, except it’s not quite a phone. It would perhaps be more accurate to say he’s building a Bluetooth handset– actual telephony remains the province of a professional device with regulatory approval, because getting custom hardware on VoLTE is a nonstarter in many places.

He starts out using an ESP32, because he already had one and why not? It’s got bluetooth, after all. Alas, audio quality he was getting through it was a little too crunchy, so he pivoted to use a dedicated Hands Free Profile (HFP) bluetooth module that is purpose built for exactly this kind of application. He’s selling the design on his website, but given how much detail he shows on screen, recreating your own version would be easy enough to save the quid. You’d be missing out on the STL for the fantastic 80s brick he’s made, which may be the most interesting part of the build to us.

We’d likely have jumped right to CAD and printed out a few iterations of the case until we were happy, but [Kevin] takes a more traditional industrial-design approach, mocking up the phone with XPS foam and a manually-operated hot wire cutter. It’s not a step we see makers take very often, but it pays off here– at least for subtracting material, it’s a very quick way to iterate, and he only needs to do one 3D print for the final version. We also like very high-tech acrylic bending jig, which he uses to put some black LED acrylic over the display.

It’s a lot of work to make you less-likely to grab a phone you still need anyway– remember, there’s no cellular modem in this– but, hey, it beats torturing yourself, or worse, a tamagotchi.

Digital Signage In The Browser With Just A Click

There are many ways to display text on a computer screen, but most require at least some manual effort from the user. It’s annoying enough even if you’re dealing with one machine, but it gets even more of a hassle when you’re trying to display something on multiple devices of varying size and capability. That’s where BIGWORDS.PAGE by [SpeakingOfBrad] comes in.

It’s essentially a simple web page you can control via a carefully crafted URL, letting you create all sorts of text displays you can “distribute” to browsers on other devices with a simple link. So, for example, if you wanted to let everyone see what your favorite website is, you need only point the browser on your phone or laptop to https://bigwords.page/#Hackaday. As the image at the top of this post shows, you can also change the font and text colors by adding a few more values.

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With Latest Update, Alexa Refuses To Pass The Aux

Although the feature has been deleted from newer models, there was a time when Amazon’s Echo devices included a 3.5 mm “aux” input jack that let you connect other audio sources to the smart speaker. Alexa would even let you switch over to an external source with a voice command — or at least, it used to.

As first reported by Reddit user [n8-sd], Amazon has started informing users that voice control over the 3.5 mm jack is no longer supported. While the physical input will still function on models equipped with it, if you want to mute the audio coming from an external device you’ll have to wade through the Alexa smartphone application to do it.

In a statement to Ars Technica, an Amazon rep confirmed that voice control over the auxiliary input has been removed as of the latest software version, and that their analytics showed not many people were using the feature in the first place. They also pointed out that no changes have been made to voice control of Bluetooth devices. While we don’t doubt that the total number of users that were physically plugging an audio source into their Echos was probably low in the grand scheme of things, that doesn’t really explain why such a simple feature needed to be actively removed.

Some commenters have theorized that the real reason behind the change is the fact that Amazon has no way of monitoring what users are playing over the auxiliary input. Since cataloging and selling the media consumption habits of users is big business these days, that’s a problem. While they might prefer to disable the feature entirely, they know that would stir up some bad press, so they’re opting to simply make it more annoying to use. We’re not saying we entirely buy this explanation, but it’s not the craziest thing we’ve ever heard either.

Although the Echo devices have never been particularly hackable, they have enjoyed a certain amount of success with tech-savvy users, making it all the more disappointing to see the ecosystem seemingly becoming less capable over time.

Lead A Discord Exodus With A Matrix Server

The Internet, and large groups of people in general, tend to have a remarkably short collective memory. Whether it’s the nature of algorithms or the people themselves to always be chasing the next novelty, maintaining long-term engagement for even relatively small changes can be challenging. Distractions abound, and motivation tends to fade over time. This past spring, Discord’s unpopular decision to force age verification resulted in a brief flash-in-the-pan of outrage that dissipated when they promised to delay its roll-out. Rather than backtrack on unpopular policies, they’ve been slowly boiling the frog with incremental changes towards this same goal in the meantime. One of the options to deal with this is to migrate over to something like a Matrix server, which has a number of benefits over Discord including being open-source and self-hostable.

Unlike Discord, a closed platform subject to the whims of a private company, Matrix is a communications protocol and open standard. Its major server and client implementations are open source, so anyone can build tools around it and integrate it with other systems that also use this protocol. This protocol-vs-platform comparison mirrors email, which is another protocol that isn’t locked down by any one company, and which can easily be used to send messages across various providers. The most commonly used server-side software for Matrix is called Synapse and the most prominent general-purpose clients are the various implementations of Element, and my exploration uses these defaults.

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The World’s Smallest TV Console Plays DOOM

We’ve seen plenty of game console projects here, many of them that seek to produce a miniature game console. But this one from [RayTriangle] may break a new barrier entirely — it fits an entire TV game console that plays DOOM, including the battery, into a TV antenna plug.

There’s a type of antenna plug with screw terminals, originally intended for matching 300 ohm balanced feeder to 75 ohm co-ax. It provides a tiny project box if you look at it that way, and it’s in here that the console sits. It’s an ESP32-S3 that talks to a controller via Bluetooth, and he’s gone into some detail on how the RF for the TV is made. Some clever tricks such as a look-up table for the phase shifted chroma waveforms for each color allow the creation of a good quality composite signal through a resistor-ladder DAC, and this is modulated in a surprisingly old-fashioned way onto a carrier provided by the ESP’s clock generator.

The result as can be seen in the video below is a bit noisy, but we think that might be fixable with a little filter magic. It’s designed for PAL TVs with a VHF tuner, but we’re guessing some ingenuity could be brought into play to make it happen for UHF or NTSC. The hardware meanwhile is put on two boards either side of the battery, with a flexible PCB joining the two.

It’s true that gaming though an analogue RF input to a TV is probably less common in 2026, but we applaud the ingenuity in getting this into such a small space. For some reason it reminds us of the world’s smallest MIDI synthesizer.

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