AI System Drops A Dime On Noisy Neighbors

“There goes the neighborhood” isn’t a phrase to be thrown about lightly, but when they build a police station next door to your house, you know things are about to get noisy. Just how bad it’ll be is perhaps a bit subjective, with pleas for relief likely to fall on deaf ears unless you’ve got firm documentation like that provided by this automated noise detection system.

OK, let’s face it — even with objective proof there’s likely nothing that [Christopher Cooper] is going to do about the new crop of sirens going off in his neighborhood. Emergencies require a speedy response, after all, and sirens are perhaps just the price that we pay to live close to each other. That doesn’t mean there’s no reason to monitor the neighborhood noise, though, so [Christopher] got to work. The system uses an Arduino BLE Sense module to detect neighborhood noises and Edge Impulse to classify the sounds. An ESP32 does most of the heavy lifting, including running the UI on a nice little TFT touchscreen.

When a siren-like sound is detected, the sensor records the event and tries to classify the type of siren — fire, police, or ambulance. You can also manually classify sounds the system fails to understand, and export a summary of events to an SD card. If your neighborhood noise problems tend more to barking dogs or early-morning leaf blowers, no problem — you can easily train different models.

While we can’t say that this will help keep the peace in his neighborhood, we really like the way this one came out. We’ve seen the BLE Sense and Edge Impulse team up before, too, for everything from tuning a bike suspension to calming a nervous dog. Continue reading “AI System Drops A Dime On Noisy Neighbors”

Synthesis Of Goldene: Single-Atom Layer Gold With Interesting Properties

The synthesis of single-atom layer versions of a range of atoms is currently all the hype, with graphene probably the most well-known example of this. These monolayers are found to have a range of mechanical (e.g. hardness), electrical (conduction) and thermal properties that are very different from the other forms of these materials. The major difficulty in creating monolayers is finding a way that works reliably and which can scale. Now researchers have found a way to make monolayers of gold – called goldene – which allows for the synthesis of relatively large sheets of this two-dimensional structure.

In the research paper by [Shun Kashiwaya] and colleagues (with accompanying press release) as published in Nature Synthesis, the synthesis method is described. Unlike graphene synthesis, this does not involve Scotch tape and a stack of graphite, but rather the wet-etching of Ti3Cu2 away from Ti3AuC2, after initially substituting the Si in Ti3SiC2 with Au. At the end of this exfoliation procedure the monolayer Au is left, which electron microscope studies showed to be stable and intact. With goldene now relatively easy to produce in any well-equipped laboratory, its uses can be explored. As a rare metal monolayer, the same wet exfoliation method used for goldene synthesis might work for other metals as well.

Combadge Project Wants To Bring Trek Tech To Life

While there’s still something undeniably cool about the flip-open communicators used in the original Star Trek, the fact is, they don’t really look all that futuristic compared to modern mobile phones. But the upgraded “combadges” used in Star Trek: The Next Generation and its various large and small screen spin-offs — now that’s a tech we’re still trying to catch up to.

As it turns out, it might not be as far away as we thought. A company called Vocera actually put out a few models of WiFi “Communication Badges” in the early 2000s that were intended for hospital use, which these days can be had on eBay for as little as $25 USD. Unfortunately, they’re basically worthless without a proprietary back-end system. Or at least, that was the case before the Combadge project got involved.

Designed for folks who really want to start each conversation with a brisk tap on the chest, the primary project of Combadge is the Spin Doctor server, which is a drop-in replacement for the original software that controlled the Vocera badges. Or at least, that’s the goal. Right now not everything is working, but it’s at the point where you can connect multiple badges to a server, assign them users, and make calls between them.

It also features some early speech recognition capabilities, with transcriptions being generated for the voices picked up on each badge. Long-term, one of the goals is to be able to plug the output of this server into your home automation system. So you could tap your chest and ask the computer to turn on the front porch light, or as the documentation hopefully prophesies, start the coffee maker.

There hasn’t been much activity on the project in the last year or so, but perhaps that’s just because the right group of rabid nerds dedicated developers has yet to come onboard. Maybe the Hackaday community could lend a hand? After all, we know how much you like talking to your electronics. The hardware is cheap and the source is open, what more could you ask for?

A Smart Power Distribution Unit For Home Automation

Power distribution units, as the name implies, are indispensable tools to have available in a server rack. They can handle a huge amount of power for demands of intensive computing and do it in a way that the wiring is managed fairly well. Plenty of off-the-shelf solutions have remote control or automation capabilities as well, but finding none that fit [fmarzocca]’s needs or price range, he ended up building his own essentially from scratch that powers his home automation system.

Because it is the power supply for a home automation system, each of the twelve outlets in this unit needed to be individually controllable. For that, three four-channel relay boards were used, each driven by an output on an ESP32. The ESP32 is running the Tasmota firmware to keep from having to reinvent the wheel, while MQTT was chosen as a protocol for controlling these outlets to allow for easy integration with the existing Node-RED-based home automation system. Not only is control built in to each channel, but the system can monitor the power consumption of each outlet individually as well. The entire system is housed in a custom-built sheet metal enclosure and painted to blend in well with any server rack.

Adding a system like this to a home automation system can simplify a lot of the design, and the scalable nature means that a system like this could easily be made much smaller or much larger without much additional effort. If you’d prefer to keep your hands away from mains voltage, though, we’ve seen similar builds based on USB power instead, with this one able to push around 2 kW.

The Myth Of Propellantless Space Propulsion Refuses To Die

In a Universe ruled by the harsh and unyielding laws of Physics, it’s often tempting to dream of mechanisms which defy these rigid restrictions. Although over the past hundred years we have made astounding progress in uncovering ways to work within these restrictions — including splitting and fusing atoms to liberate immense amounts of energy — there are those who dream of making reality a bit more magical. The concept of asymmetrical electrostatic propulsion is a major player here, with the EmDrive the infamous example. More recently [Dr. Charles Buhler] proposed trying it again, as part of his company Exodus Propulsion Technologies.

This slide from Dr. Buhler’s APEC presentation shows the custom-made vacuum chamber built to test their propellantless Propulsion drive in a simulated space environment. Image Credit: Exodus Propulsion Technologies, Buhler, et al.
This slide from Dr. Buhler’s APEC presentation shows the custom-made vacuum chamber built to test their propellantless Propulsion drive in a simulated space environment. Image Credit: Exodus Propulsion Technologies, Buhler, et al.

The problem with such propellantless space propulsion proposals is that they violate the core what we know about the physical rules, such as the conclusion by Newton that for any action there has to be an opposite reaction. If you induce an electrostatic field or whatever in some kind of device, you’d expect any kind of force (‘thrust’) this creates to act in all directions equally, ergo for thrust to exist, it has to push on something in the other direction. Rocket and ion engines (thrusters) solve this by using propellant that create the reaction mass.

The EmDrive was firmly disproven 2021 by [M. Tajmar] and colleagues in their paper titled High-accuracy thrust measurements of the EMDrive and elimination of false-positive effects as published in CEAS Space Journal, which had the researchers isolate the EmDrive from all possible outside influences. Since the reported thrust was on the level of a merest fraction of a Newton, even the impact from lighting in a room and body heat from the researchers can throw off the results, not to mention the heat developed from a microwave emitter as used in the EmDrive.

Meanwhile True Believers flock to the ‘Alt Propulsion Engineering Conference’ (APEC), as no self-respecting conference or scientific paper will accept such wishful claims. In the case of [Buhler], he claims that their new-and-improved EmDrive shows a force of 10 mN in a ‘stacked system’, yet no credible paper on the experiments can be found other than APEC presentations. Until their prototype is tested the way the EmDrive was tested by [M. Tajmar] et al., it seems fair to assume that the rules of physics as we know them today remain firmly intact.

Reverse Engineering A Fancy Disposable Vape

Many readers will be aware of the trend for disposable vapes, and how harvesting them for lithium-ion batteries has become a popular pastime in our community. We’re all used to the slim ones about the size of a marker pen, but it’s a surprise to find that they also come in larger sizes equipped with colour LCD screens. [Jason Gin] received one of this type of vape, and set about reverse engineering it.

What he found inside alongside the lithium-ion cell (we love his use of the term ” street lithium” by the way) was an ARM Cortex M0 microcontroller, 1 MB of flash, and that 80×160 display. Some investigation revealed this last part to have an ST7735S controller with an SPI interface. He turned his attention to the flash, which was filled with the bitmaps for the display. Seeing an opportunity there, this lead to the creation of a Windows 95 theme for the device.

Finally, the microcontroller turned out to be accessible with programming tools, with an unprotected firmware. The reverse engineering effort is ongoing, but we hope the result is a small dev board that will at least save some of the from being e-waste. If you’re curious, all the tools used are in a GitHub repository.

Meanwhile, we’ve looked at street lithium harvesting before.

Thanks [DeadFishOnTheLanding] for the tip!

Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The Transmitting Typewriter

Image by [SrBlonde] via Hackaday.IO
Okay, so we’re opening with more than just a keyboard, and that’s fine. In fact, it’s more than fine, it’s probably the cutest lil’ ZX Spectrum you’ll see today.

[SrBlonde]’s wonderful micro Spectrum project has only the essential inputs, which makes for an interesting-looking keyboard for sure. Inside you’ll find an Orange Pi Zero 2 board loaded with Batocera so [SrBlonde] can play all their favorite childhood games on the 5″ IPS display.

Something else that’s interesting is that the switches are a mix of blues and blacks — clickies and linears. I can’t figure out how they’re distributed based on the numbers in the components list, but I could see using clickies on the alphas and linears everywhere else (or vice versa). At any rate, it’s a great project, and you can grab the STL files from Thingiverse if you’re so inclined.

Continue reading “Keebin’ With Kristina: The One With The Transmitting Typewriter”