RF Detector Chip Helps Find Hidden Cameras And Bugs

October 26, 2024 by Jenny List 6 Comments

It’s a staple of spy thriller movies, that the protagonist has some kind of electronic scanner with which he theatrically searches his hotel room to reveal the bad guys’ attempt to bug him. The bug of course always had a flashing LED to make it really obvious to viewers, and the scanner was made by the props department to look all cool and futuristic.

It’s not so far-fetched though, while bugs and hidden cameras in for example an Airbnb may not have flashing LEDs, they still emit RF and can be detected with a signal strength meter. That’s the premise behind [RamboRogers]’ RF hunter, the spy movie electronic scanner made real.

At the rear of the device is an ESP32, but the front end is an AD8317 RF detector chip. This is an interesting and useful component, in that it contains a logarithmic amplifier such that it produces a voltage proportional to the RF input in decibels. You’ll find it at the heart of an RF power meter, but it’s also perfect for a precision field strength meter like this one. That movie spy would have a much higher chance of finding the bug with one of these.

For the real spies of course, the instruments are much more sophisticated.

A Birthday Cake For A Retrocomputer Designer

October 25, 2024 by Jenny List 6 Comments

When making a birthday cake a bit more personal, one can create a novelty themed confection appropriate for the lucky recipient. In the case of [Spencer Owen], who you may know as the creator of the RC2014 retrocomputing ecosystem, it was appropriate to have one of the little machines at work somewhere, so [peahen] did just that. The result is a cake in the shape of an IMSAI 8080 microcomputer, but it does more than just look the part. This is a working replica of the classic machine, powered as you might expect by an RC2014 sitting next to it.

The lights are a set of addressable LEDs, and the switches are made from appropriately colored sweets. Sadly the plan to make these capacitive touch switched failed as the wiring became buried in the icing, but the LEDs deserve a second look. They’re encased in translucent heatshrink sleeving which is embedded under a layer of white icing, which is translucent enough, but on top for the classic panel light look are a set of edible cake-maker’s jewels. Best of all while all except the electronics is edible, the front panel is robust enough to have been removed from the cake in one and thus will live on.

We rather like the idea of electronics meeting sugarcraft, because fondant is a surprisingly versatile medium that deserves attention much further than just confectionery. We remember it being a popular cheap way to experiment with 3D printing back at the dawn of open source printers, and it still has some potential. Meanwhile if you’ve not seen the RC2014 we reviewed its original version back in 2016, and since then it’s evolved to become an ecosystem in its own right.

75-In-One Music

October 23, 2024 by Jenny List 18 Comments

It’s likely that many Hackaday readers will have had their interest in electronics as a child honed by exposure to an electronics kit. The type of toy that featured a console covered in electronic components with spring terminals, and on which a variety of projects could be built by wiring up circuits. [Matthew North Music] has a couple of these, and he’s made a video investigating whether they can be used to make music.

The kits he’s found are a Radio Shack one from we’re guessing the 1970s, and a “Cambridge University Recording Studio” kit that looks to be 1990s-vintage. The former is all discrete components and passive, while the latter sports that digital audio record/playback chip that was the thing to have in a novelty item three decades ago. With them both he can create a variety of oscillator and filter circuits, though for the video he settles for a fairly simple tone whose pitch is controlled by an light-dependent resistor, and a metronome as a drum beat.

The result is a little avant garde, but certainly shows promise. The beauty of these kits is they can now be had for a song, and as grown-ups we don’t have to follow the rules set out in the book, so we can see there’s a lot of fun to be had. We look forward to some brave soul using them in a life performance at a hacker camp. Continue reading “75-In-One Music” →

Save A Packet, Use Cheap Co-Ax!

October 21, 2024 by Jenny List 58 Comments

Anyone who works with radio transmitters will know all about matching and impedance, and also about the importance of selecting the best co-axial cable connecting transistor and antenna. But here’s [Steve, KD2WTU] with a different take, he’s suggesting that sometimes a not-so-good co-ax choice can make the grade. He’s passing up expensive 50 ohm cable in favour of the cheap and ubiquitous 75 ohm RG6 cable used in domestic TV and satellite receiver installations.

Fighting that received wisdom, he outlines the case for RG6. It’s cheap and it has a surprisingly low loss figure compared to some more conventional choices, something that shouldn’t be a surprise once we consider that it’s designed to carry GHz-plus signals. Where it loses is in having a lower maximum power rating. Power shouldn’t be a problem to a shoestring ham for whom 100W is QRO. Another issue is that 75 ohm coax necessitates a tuner for 50 ohm transmitters. It also has the effect of changing the resonance of some antennas, meaning a few mods may be in order.

So we’re convinced, and with the relatively QRP shack here we can’t see RG6 being a problem. Maybe it’s something to try in out next antenna experiment. Meanwhile if you’re interested in some of the background on co-ax impedance choices, we’ve been there before.

Continue reading “Save A Packet, Use Cheap Co-Ax!” →

Forget Flipper, How About Capybara?

October 20, 2024 by Jenny List 26 Comments

One of the hacker toys to own over the last year has been the Flipper Zero, a universal wireless hacking tool which even caused a misplaced moral panic about car theft in Canada. A Flipper is cool as heck of course but not the cheapest of devices. Fortunately there’s now an alternative in the form of the CapibaraZero. It’s a poor-hacker’s Flipper Zero which you can assemble yourself from a heap of inexpensive modules.

At the center is an ESP32-S3 board, which brings with it that chip’s wireless and Bluetooth capabilities. To that is added an ST7789 TFT display, a PN532 NFC reader, an SX1276 LoRa and multi-mode RF module, and an IR module. The firmware can be found through GitHub. Since the repo is nearly two years old and still in active development, we’re hopeful CapibaraZero will gain features and stability.

If you’re interested in our coverage of the Canadian Flipper panic you can read it here, and meanwhile if you’re using one of those NFC modules, consider tuning it.

A Hacker’s Travel Guide To Europe

October 18, 2024 by Jenny List 55 Comments

This summer, I was pleasantly surprised when a friend of mine from Chicago turned up at one of the hacker camps I attended. A few days of hanging out in the sun ensued, doing cool hacker camp stuff, drinking unusual beverages, and generally having fun. It strikes me as a shame that this is such a rare occurrence, and since Hackaday is an American organisation and I am in a sense writing from its European outpost, I should do what I can to encourage my other friends from the USA and other parts of the world to visit. So here I’m trying to write a hacker’s guide to visiting Europe, in the hope that I’ll see more of you at future camps and other events.

It’s Intimidating. But Don’t Worry.

Danish road sign: "Se efter tog", or according to Google Translate: "Look for trains". — Yes. We’d find this intimidating, too. Bewitchedroutine, Public domain.

First of all, I know that it’s intimidating to travel to an unfamiliar place where the language and customs may be different. I’m from England, which sits on a small island in the North Atlantic, and believe it or not it’s intimidating for us to start traveling too. It involves leaving the safety of home and crossing the sea whether by flight, ferry, or tunnel, and that lies outside one’s regular comfort zone.

Americans live in a country that’s almost a continent in its own right, so you can satisfy your travel lust without leaving home. Thus of course the idea of landing in Germany or the Netherlands is intimidating. But transatlantic flights are surprisingly cheap in the scheme of international travel because of intense competition, so I’m here to reassure you that you can travel my continent ‘s hacker community without either feeling out of your depth, or breaking the bank.

Continue reading “A Hacker’s Travel Guide To Europe” →

Winamp Taken Down: Too Good For This Open Source World

October 16, 2024 by Jenny List 58 Comments

If you picked today in your hackerspace’s sweepstake on when Winamp would pull their code repository, congratulations! You’re a winner! The source for the Windows version of the venerable music player was released on GitHub three weeks ago, and after some derision over its licence terms, a bunch of possible open source violations, and the inadvertent release of some proprietary third-party code, it’s been taken down. We’re sure that if you still have a burning desire to look at it then it won’t be too difficult to find a copy through your favorite search engine, leaving the question of what really just happened.

It’s fairly obvious that the owners of the code lacked some level of understanding of just what open source really is, based on their not-really-open licence and all those code leaks. They did back down on not allowing people to create forks, but it’s evident that they didn’t anticipate the reaction they got. So were they merely a bit clueless, or was it all just a publicity stunt involving a piece of software that’s now of more historical than practical interest? It’s possible we’ll never know, but the story has provided those of us sitting on the fence eating popcorn with some entertainment.