Getting To Know The TP223 Capacitive Touch Sensor

October 9, 2026 by No comments

Mechanical and prone to failure, switches can seem quaint these days. Plus, everyone is used to having touch screens on their phones and other devices. So why not use touch sensors on your next project? [Tarantula3] has details on using the TP223 instead of ordinary switches.

These inexpensive modules work through plastic, glass, or wood, opening up many interesting possibilities for building a front panel. Of course, the thicker the surface above the module, the less sensitive the switch is, but that’s not always a bad thing. In particular, you may want to reduce sensitivity anyway. Thicker panels, reducing the size of the touch pad, or adding an external capacitor can reduce the sensor’s range.

You may be worried about eating up batteries with a bunch of electronic switches. But according to [Tarantula3], the modules consume less than 2 microamps at rest. You can configure the modules with our favorite scripting language: solder. There are two jumpers, initially unsoldered, and this results in four possible states. By default, the output goes high when someone is touching the sensor and stays high until they release.

However, you can solder jumper A to invert the output. Jumper B causes the switch output to toggle on each press. Of course, you can also do both jumpers, which toggles but has the opposite default state. If you get false triggers, consider adding a small capacitor to filter the power supply to the module.

These would be great “drop ins” for 3D printing to add switches to your designs. You might even be able to use these as power switches with a little work.

This Week In Security: New Spectre Attacks, Crushing Quantity Of Linux Vulns, Google Gets Too Much AI, And Hacking Lawnmowers

October 9, 2026 by No comments

Just-in-time, or JIT, compilation could be considered a fundamental backbone of modern computing.  JIT compilation turns scripting languages like JavaScript or intermediary binary forms like Web Assembly into native code on the fly, giving web apps, and things that are web apps under the covers like Electron-based tools, near native speed.  A new paper explores leveraging JIT systems to revive Spectre-v2 attacks against processors.

Most modern processors gain performance by using a trick called “speculative execution”.  The processor guesses the likely result of a compare, and begins executing some of the next instructions before the results are actually known.  If the processor guessed right, things continue and there is a speed gain because it can jump ahead, but if the processor guessed wrong, any instructions that were run and any side effects of running them are discarded and execution resumes on the actual path.  In theory, anyhow.

In practice, the Spectre class of attacks targets branch prediction. It was discovered that when the wrong branch was chosen, not all of the results were truly hidden; Patterns of failures in guessing branches can be used to leak behavior processing encryption keys and other activities. The attacks evolved with the research dubbed Spectre-V2, which showed that non-privileged contexts, like non-root users and virtual machines, could poison the instruction prediction and use it to read arbitrary memory.  Fixes to the Linux kernel and other platforms were required to mitigate the worst of the effects.

The paper shows that by using self-modifying code in the JIT, the processor can be tricked into loading cached versions of the instructions.  The fixes to the kernel to prevent Spectre attacks include identifying malicious code patterns that attack the branch prediction, and stopping or changing them:  By causing the CPU to execute the cached copy of instructions instead of the live copy, the attack ignores the fixed instructions entirely and can attack the branch prediction algorithm.

To prove the attack is feasible in the real world, the researchers targeted several JIT compilers, including the SpiderMonkey JavaScript engine used by Firefox, the eBPF JIT found in the Linux kernel, and GraalVM, the JIT used in Python.  They found success with each, demonstrating that the attack is at least plausible.

Research like this is unlikely to be an instant world-melter, and will help find possible mitigations in the future to prevent these sorts of attacks.  Operating systems that support a high-security “lock-down” mode, like macOS and iOS, often disable JIT entirely, out of concern about these sorts of attacks.  There’s probably no need to start disabling JIT on every system, but attacks like these have a tendency to evolve.

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Margret Hamilton, Pioneering Software Engineer, Dies Aged 90

October 9, 2026 by 6 Comments

As Director of the Software Engineering Division at the MIT Instrumentation Laboratory, Margret Hamilton was responsible for the software for the Apollo program. The code she was responsible for ran the lunar lander, and brought multiple missions successfully to the surface of Luna and back to orbital rendezvous. We regret to inform you that she passed on September 30th of 2026, aged 90 years.

Hamilton, with the code that put men on the moon.

If you call yourself a software engineer, you have her to thank. Hamilton didn’t just help define the field through her efforts, she literally coined the term while at NASA in an effort to get “mere” programming taken more seriously. Suffice to say, that ambition was realized, and few see programmer as a low-status career these days.

After decades of obscurity, known only to those willing to dive deep into the Apollo program to discover her work there, Hamilton found deserved fame late in life. Her likeness eventually found its way to classroom posters and even an official LEGO figure. She also got the Presidential Medal of Freedom, but we don’t see how that could possibly compare to being immortalized in LEGO.

Some have called her a feminist icon, blazing a trail for girls and women. While that’s true enough, it’s also thinking perhaps too small. Like the missions she did so much to make successful, Margret Hamilton blazed a trail for all of humanity.

We wish Margret’s family the best as she blazes a trail we all must someday follow into that one last undiscovered country. Our own biographical tribute is several years old now, but it bares rereading in light of this news.

Belt File From Old Mixer And Junk Bin Parts

October 9, 2026 by 2 Comments

Making one’s own power tools can be a rewarding way to upcycle parts, and [bluesyann] does exactly that with a belt file made from an old mixer. We like how the enclosure for the old mixer is preserved and acts as a handle, so there’s no need to worry about motor mounting and wiring separately. It looks perfectly usable, and all the hardware needed is the sort of thing one finds in a scrap pile.

[bluesyann] stretches the sanding belt between a 3D printed pulley attached to the mixer motor, and a bearing fitted into the end of some aluminum U-channel. Scrap wood and more nested U-channel make up the rest of the assembly, and there’s even a tension adjustment made from a threaded rod.

There’s a bill of materials and a 3D model for the pulley, but a build like this is more about sharing the broad strokes rather than the exact design. Whenever one modifies or integrates an existing piece of equipment (the mixer, in this case) into a project, most of the work is about working with and around the bits one can’t change.

Watch it in action in a brief video, embedded just below. If you like the idea but don’t have a mixer like the one [bluesyann] used, let us point you toward a similar DIY attachment to get a similar result from a common angle grinder.

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Low Current Density Nickel Plating

October 8, 2026 by 8 Comments

We imagine that electroplating is like making PC boards or soldering surface-mount chips. Before you’ve done it, it seems like a lot. Afterward, you can’t remember why it was such a big deal. [Kovancapol] wants to show you how to plate a mirror-finish nickel over your tools, and while it looks like a lot to set up, we are guessing that it gets easy once you have everything together.

There is a bit of chemical setup, as you might expect with reagents like nickel sulfate and nickel chloride. Then there’s the glassware, nickel anodes, and a power supply. As you can see in the video, the results look very nice. We can’t help but wonder what other uses you might have for this process.

A conductive coating on a 3D print might be feasible. We aren’t sure soldering PCB traces would be worth it since nickel gets hard to solder as it oxidizes. You can mix and match plating for some pretty impressive results.

Introducing The Garlic-Powered Door And Window Sensor

October 8, 2026 by 8 Comments

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

October 8, 2026 by 21 Comments

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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