Build Your Own Class-E Musical Tesla Coil

We’ve all seen a million videos online with singing Tesla coils doing their thang. [Zach Armstrong] wasn’t content to just watch, though. He went out and built one himself! Even better, he’s built a guide for the rest of us, too!

His guide concerns the construction of a Class-E solid state Tesla coil. These are “underrated” in his opinion, as they’re simple, cheap, and incredibly efficient. Some say up to 95% efficient, in fact! It’s not something most Tesla coil fans are concerned with, but it’s nice to save the environment while making fun happy sparks, after all.

[Zach]’s guide doesn’t just slap down a schematic and call it good. He explains the theory behind it, and the unique features too. He uses an adjustable Schmitt trigger oscillator for the build, and he’s naturally given it an audio modulation capability because that’s a good laugh, too.

If you’ve ever wanted to convince you’re friends you’re incredibly smart and science-y, you can’t go wrong with a singing Tesla coil. This beats out Jacob’s ladder and most other plasma experiments for sheer mad scientist cred.

Have fun out there! Video after the break.

Continue reading “Build Your Own Class-E Musical Tesla Coil”

2024 Home Sweet Home Automation: Spray Bottle Turret Silences Barking

Ah, dogs. They sure like to bark, don’t they? [rrustvold]’s dog likes to bark at the door when a package arrives. Or when someone walks by the house, or whenever the mood strikes, really. To solve the barking issue, at least near the front door, [rrustvold] built a spray bottle turret to teach the dog through classical conditioning.

As you can see from the image, it’s all about pulling the trigger on a standard spray bottle at the right time. This machine only sprays when two conditions are met: it hears noise (like barking) and detects motion (like overzealous tail wagging). It also has heat-seeking abilities thanks to a Raspberry Pi thermal camera.

To do the actual spraying, there’s a DC motor mounted behind the bottle which turns a pulley that’s mounted to its shaft. Around the pulley is a string that wraps around the spray bottle’s trigger. To complete the build, everything is mounted on a lazy Susan so there’s nowhere for Fido to hide-o.

If you’ve a dog whose bite is worse than its bark, consider building a custom dog door to keep it out of the cat box.

The 2024 Home Sweet Home Automation contest has officially wrapped — we’re counting the votes now, so stay tuned for an announcement about the winners shortly.

Hackaday Podcast Episode 268: RF Burns, Wireless Charging Sucks, And Barnacles Grow On Flaperons

Not necessarily the easy way to program an EPROM

Elliot and Dan got together to enshrine the week’s hacks in podcast form, and to commiserate about their respective moms, each of whom recently fell victim to phishing attacks. It’s not easy being ad hoc tech support sometimes, and as Elliot says, when someone is on the phone telling you that you’ve been hacked, he’s the hacker. Moving on to the hacks, we took a look at a hacking roadmap for a cheap ham radio, felt the burn of AM broadcasts, and learned how to program old-school EPROMs on the cheap.

We talked about why having a smart TV in your house might not be so smart, especially for Windows users, and were properly shocked by just how bad wireless charging really is. Also, cheap wind turbines turn out to be terrible, barnacles might give a clue to the whereabouts of MH370, and infosec can really make use of cheap microcontrollers.

Grab a copy for yourself if you want to listen offline.

Continue reading “Hackaday Podcast Episode 268: RF Burns, Wireless Charging Sucks, And Barnacles Grow On Flaperons”

This Week In Security: Cisco, Mitel, And AI False Flags

There’s a trend recently, of big-name security appliances getting used in state-sponsored attacks. It looks like Cisco is the latest victim, based on a report by their own Talos Intelligence.

This particular attack has a couple of components, and abuses a couple of vulnerabilities, though the odd thing about this one is that the initial access is still unknown. The first part of the infection is Line Dancer, a memory-only element that disables the system log, leaks the system config, captures packets and more. A couple of the more devious steps are taken, like replacing the crash dump process with a reboot, to keep the in-memory malware secret. And finally, the resident installs a backdoor in the VPN service.

There is a second element, Line Runner, that uses a vulnerability to arbitrary code from disk on startup, and then installs itself onto the device. That one is a long term command and control element, and seems to only get installed on targeted devices. The Talos blog makes a rather vague mention of a 32-byte token that gets pattern-matched, to determine an extra infection step. It may be that Line Runner only gets permanently installed on certain units, or some other particularly fun action is taken.

Fixes for the vulnerabilities that allowed for persistence are available, but again, the initial vector is still unknown. There’s a vulnerability that just got fixed, that could have been such a vulnerability. CVE-2024-20295 allows an authenticated user with read-only privileges perform a command injection as root. Proof of Concept code is out in the wild for this one, but so far there’s no evidence it was used in any attacks, including the one above. Continue reading “This Week In Security: Cisco, Mitel, And AI False Flags”

Microsoft Updates MS-DOS GitHub Repo To 4.0

We’re not 100% sure which phase of Microsoft’s “Embrace, Extend, and Extinguish” gameplan this represents, but just yesterday the Redmond software giant decided to grace us with the source code for MS-DOS v4.0.

To be clear, the GitHub repository itself has been around for several years, and previously contained the source and binaries for MS-DOS v1.25 and v2.0 under the MIT license. This latest update adds the source code for v4.0 (no binaries this time), which originally hit the market back in 1988. We can’t help but notice that DOS v3.0 didn’t get invited to the party — perhaps it was decided that it wasn’t historically significant enough to include.

That said, readers with sufficiently gray beards may recall that DOS 4.0 wasn’t particularly well received back in the day. It was the sort of thing where you either stuck with something in the 3.x line if you had older hardware, or waited it out and jumped to the greatly improved v5 when it was released. Modern equivalents would probably be the response to Windows Vista, Windows 8, and maybe even Windows 11. Hey, at least Microsoft keeps some things consistent.

It’s interesting that they would preserve what’s arguably the least popular version of MS-DOS in this way, but then again there’s something to be said for having a historical record on what not to do for future generations. If you’re waiting to take a look at what was under the hood in the final MS-DOS 6.22 release, sit tight. At this rate we should be seeing it sometime in the 2030s.

How To Cast Silicone Bike Bits

It’s a sad fact of owning older machinery, that no matter how much care is lavished upon your pride and joy, the inexorable march of time takes its toll upon some of the parts. [Jason Scatena] knows this only too well, he’s got a 1976 Honda CJ360 twin, and the rubber bushes that secure its side panels are perished. New ones are hard to come by at a sensible price, so he set about casting his own in silicone.

Naturally this story is of particular interest to owners of old motorcycles, but the techniques should be worth a read to anyone, as we see how he refined his 3D printed mold design and then how he used mica powder to give the clear silicone its black colour. The final buses certainly look the part especially when fitted to the bike frame, and we hope they’ll keep those Honda side panels in place for decades to come. Where this is being written there’s a CB400F in storage, for which we’ll have to remember this project when it’s time to reactivate it.

If fettling old bikes is your thing then we hope you’re in good company here, however we’re unsure that many of you will have restored the parts bin for an entire marque.

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”