Hackaday Podcast Episode 336: DIY Datasette, Egg Cracking Machine, And Screwing 3D Prints

September 5, 2025 by No comments

Thunderstorms were raging across southern Germany as Elliot Williams was joined by Jenny List for this week’s podcast. The deluge outside didn’t stop the hacks coming though, and we’ve got a healthy smorgasbord for you to snack from. There’s the cutest ever data cassette recorder taking a tiny Olympus dictation machine and re-engineering it with a beautiful case for the Commodore 64, a vastly overcomplex machine for perfectly cracking an egg, the best lightning talk timer Hackaday has ever seen, and a demoscene challenge that eschews a CPU. Then in Quick Hacks we’ve got a QWERTY slider phone, and a self-rowing canoe that comes straight out of Disney’s The Sorcerer’s Apprentice sequence.

For a long time we’ve had a Field guide series covering tech in infrastructure and other public plain sight, and this week’s one dealt with pivot irrigation. A new subject for Jenny who grew up on a farm in a wet country. Then both editors are for once in agreement, over using self-tapping screws to assemble 3D-printed structures. Sit back and enjoy the show!

Want to listen offline?  Grab yourself an MP3 hot off the press.

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Estes Wants You To 3D Print Their New Model Rocket

September 5, 2025 by 45 Comments

The Estes line of flying model rockets have inspired an untold number of children and adults alike, thanks in part to their simplicity. From the design and construction of the rockets themselves to the reliability and safety of the modular solid-propellant motors, the company managed to turn actual rocket science into a family activity. If you could glue fins onto a cardboard tube and stick a plastic nosecone on the end, you were nearly ready for launch.

But what if you’re looking for something a bit more challenging? That’s where the new Estes Scorpio 3D comes in. Unlike the classic Estes kit, which included the fins, nosecone, and other miscellaneous bits of the rocket, the Scorpio kit requires you to 3D print your own parts. Do it right, and the company says you can send your creation to heights of 1,000 feet (305 m).

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This Week In Security: DNS Oops, Novel C2s, And The Scam Becomes Real

September 5, 2025 by 7 Comments

Something rather significant happened on the Internet back in May, and it seems that someone only noticed it on September 3rd. [Youfu Zhang] dropped a note on one of the Mozilla security mailing lists, pointing out that there was a certificate issued by Fina for 1.1.1.1. That IP address may sound familiar, and you may have questions.

First off, yes, TLS certificates can be issued for IP addresses. You can even get a numeric TLS certificate for your IP address, via Lets Encrypt. And second, 1.1.1.1 sounds familiar because that’s CloudFlare’s public DNS resolver. On that address, Cloudflare notably makes use of DoH, a charming abbreviation for DNS over HTTPS. The last important detail is that Cloudflare didn’t request or authorize the certificate. Significant indeed.

This is a high-profile example of the major weakness of the TLS certificate system. There are over 300 trusted certificate authorities in the Microsoft Root Certificate Program, Financijska agencija (Fina) being one of them. All it takes is for one of those trusted roots to issue a bad certificate, to compromise that system. That it took four months for someone to discover and point out the problem isn’t great. Continue reading “This Week In Security: DNS Oops, Novel C2s, And The Scam Becomes Real” →

Heart Rate Monitoring Via WiFi

September 5, 2025 by 22 Comments

Before you decide to click away, thinking we’re talking about some heart rate monitor that connects to a display using WiFi, wait! Pulse-Fi is a system that monitors heart rate using the WiFi signal itself as a measuring device. No sensor, no wires, and it works on people up to ten feet away.

Researchers at UC Santa Cruz, including a visiting high school student researcher, put together a proof of concept. Apparently, your heart rate can modify WiFi channel state information. By measuring actual heart rate and the variations in the WiFi signal, the team was able to fit data to allow for accurate heart rate prediction.

The primary device used was an ESP32, although the more expensive Raspberry Pi performed the same trick using data generated in Brazil. The Pi appeared to work better, but it is also more expensive. However, that implies that different WiFi chipsets probably need unique training, which, we suppose, makes sense.

Like you, we’ve got a lot of questions about this one — including how repeatable this is in a real-world environment. But it does make you wonder what we could use WiFi permutations to detect. Or other ubiquitous RF signals like Bluetooth.

No need for a clunky wristband. If you could sense enough things like this, maybe you could come up with a wireless polygraph.

Capture And Plot Serial Data In The Browser

September 5, 2025 by 5 Comments

If you’re working with a microcontroller that reads a sensor, the chances are that at some point you’re faced with a serial port passing out continuous readings. The workflow of visualizing this data can be tedious, involving a cut-and-paste from a terminal to a CSV file. What if there were a handy all-in-one serial data visualization tool, a serial data oscilloscope, if you will? [Atomic14] has you covered, with the web serial plotter.

It’s a browser-based tool that uses the WebSerial API, so sadly if you’re a Firefox user you’re not invited to the party. Serial data can be plotted and exported, and there are a range of options for viewing. Behind the scenes there’s some Node and React magic happening, but should you wish to avoid getting your hands dirty there’s an online demo you can try.

Looking at it we’re ashamed to have been labouring under a complex workflow, particularly as we find this isn’t the first to appear on these pages.

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Powering A Submarine With Rubber Bands

September 4, 2025 by 16 Comments

A look underneath the water’s surface can be fun and informative! However, making a device to go under the surface poses challenges with communication and water proofing. That’s what this rubber band powered submarine by [PeterSripol] attempts to fix!

The greatest challenge of building such a submersible was the active depth control system. The submarine is slightly negatively buoyant so that once the band power runs out, it returns to the surface. Diving is controlled by pitch fins, which will pitch downward under the torque applied by the rubber bands. Once the rubber band power runs out, elastic returns the fins to their natural pitch up position encouraging surfacing of the submarine. However, this results in uncontrolled dives and risks loss of the submersible.

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Figure 7-8, caption: Example thrust sheet rotation using tether control. Credit: NASA/James Bickford.

TFINER Is An Atompunk Solar Sail Lookalike

September 4, 2025 by 16 Comments

It’s not every day we hear of a new space propulsion method. Even rarer to hear of one that actually seems halfway practical. Yet that’s what we have in the case of TFINER, a proposal by [James A. Bickford] we found summarized on Centauri Dreams by [Paul Gilster] .

TFINER stands for Thin-Film Nuclear Engine Rocket Engine, and it’s a hoot.  The word “rocket” is in the name, so you know there’s got to be some reaction mass, but this thing looks more like a solar sail. The secret is that the “sail” is the rocket: as the name implies, it hosts a thin film of nuclear materialwhose decay products provide the reaction mass. (In the Phase I study for NASA’s Innovative Advanced Concepts office (NIAC), it’s alpha particles from Thorium-228 or Radium-228.) Alpha particles go pretty quick (about 5% c for these isotopes), so the ISP on this thing is amazing. (1.81 million seconds!) Continue reading “TFINER Is An Atompunk Solar Sail Lookalike” →