RF Detector Chip Helps Find Hidden Cameras And Bugs

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.

Clockwork Derby gameboard

Clockwork Derby: Digital Robo Rally, Steampunk Style

Inspired by the classic game Robo Rally, [Ytec3D]’s Clockwork Derby takes tabletop gaming to the next level by combining steampunk aesthetics with automation. We recently had the chance to see it live at Hackfest, together with [Ytec3D]’s animatronic tentacle, and we can say that his new take on playful robotics offers a unique experience for game enthusiasts. The 300×420 mm board uses magnets, motors, and card readers to handle up to eight players, creating a smooth, automated version of Robo Rally where players can focus on strategy while the board handles movement.

In Clockwork Derby, game pieces are moved by a magnetic system controlled by the board, which rotates and shifts pieces in real-time. Each player uses a card reader to program moves, with up to five cards per round. The board scans these cards via barcode scanners, so you don’t have to worry about tracking your moves or adjusting game pieces manually. [Ytec3D]’s game rules have been optimized for the automated setup, allowing for smoother gameplay and an emphasis on strategic choices.

The project is a standout for hackers and tinkerers who appreciate blending physical mechanics with digital precision. It’s a great example of how classic games can be modernized with a bit of ingenuity and tech. For those interested in DIY gaming projects or automation, Clockwork Derby is definitely worth exploring. To dive deeper into the build details and see more of the project, visit [Ytec3D]’s project page for an in-person look at this inventive tabletop game!

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Hack On Self: The Alt-Tab Annihilator

Last time, I told you about a simple script I made to collect data about my laptop activity, talked about why collecting data about yourself is a moral imperative, and shared the upgraded script with you alongside my plans for it. Today, I will show you a problem I’ve been tackling, with help of this script and the data it gives, and I also would love to hear your advice on a particular high-level problem I’m facing.

Today’s problem is as old as time – I often can’t focus on tasks I badly need done, even ones I want done for myself. This has been a consistent problem in my life, closing off opportunities, getting me to inadvertently betray my friends and family, hurting my health and well-being, reinforcing a certain sort of learned helplessness, and likely reinforcing itself as it goes, too.

It’s deeply disturbing to sit down fully intending to work on a project, then notice no progress on it hours later, and come to a gut-wrenching realization you’ve had hundreds of such days before – I think this screws with you, on a fundamental level. Over the years, I’ve been squeezing out lessons from this failure mode, making observations, trying out all sorts of advice, in search of a solution.

Join me today in non-invasive brain augmentation and reprogramming, as I continue trying to turn my life around – this time, with help of my laptop, a computer that I already spend a ton of time interfacing with. Ever notice that starting work on a task  is often the hardest part of it? It’s the same for me, and I decided to hack away at it.

Staying On Track

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Two hands hold a rounded rectangular case with a small lollipop-shaped cutout. The case is dark grey with a bit of white protruding between the two halves in the middle.

Add USB-C To Your AirPods The Easy Way

While the death of Apple’s Lightning Connector can’t come soon enough, swapping the ports on their products as “category-defining innovations” seems a bit of a stretch. [Ken Pillonel] has designed a set of streamlined, repairable, USB-C adapters for the AirPods, AirPods Pro, and AirPods Max that show Apple what innovation really means.

If you’ve followed [Pillonel]’s work in the past, you’ll know he’s as a big a fan of repairability as we are here, so this isn’t just a cheap knockoff dongle that’ll be in the trash as fast as your counterfeit wireless earbuds. In the video below, he walks us through his quest start-to-finish to design something compact that gives you all the joys of USB-C without the pain of buying a whole new set of headphones.

We like the iteration on the connector, showing that flexible circuits can do some amazing things, but are still subject to failure at extreme angles. Using a combination of 3D printing, a cool robot sandblasting machine, a pick-and-place, and some old fashioned hand soldering, [Pillonel] treats us to a polished final product that’s put together with actual screws and not adhesive. His designs are all open source, so you can DIY, or he sells finished copies in his shop if you want to give one to your less-than-techy relatives.

[Pillonel] may seem familiar as he’s the guy who added USB-C to the iPhone before Apple and redesigned the AirPods Pro case for repairability. Apple is getting better about repair in some of its devices, for sure, but unsurprisingly, hackers do it better.

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2024 Hackaday Superconference Speakers, Round One

Supercon is the Ultimate Hardware Conference and you need to be there! We’ve got a stellar slate of speakers this year — way too many to feature in one post. So here’s your first taste, and a reminder that Supercon will sell out so get your tickets now before it’s too late.

In addition to the full-length talks, we’ve got a series of Lightning Talks, so if you want to share seven minutes’ of insight with everyone there, please register your Lightning Talk idea now.

But Supercon has a lot more than just talks! The badge heavily features Supercon Add-Ons, and we want to see the awesome SAOs you are working on. There will be prizes, and we’ll manufacture four of our favorite designs in small batches for the winners, and make a full run for Hackaday Europe in 2025. Want to know more about SAOs? They’re the ideal starter PCB project.

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Archiving Data On Paper Using 2D Images

It seems like only yesterday we covered a project using QR codes to archive data on paper (OK, it was last Thursday), so here’s another way to do it, this time with a dedicated codec using the full page. Optar or OPTical ARchiver is a project capable of squeezing a whopping 200 Kb of data onto a single A4 sheet of paper, with writing and reading achieved with a standard laser printer and a scanner. It’s a bit harder than you might think to get that much data on the page, given that even a 600 DPI printer can’t reliably place every dot each time. Additionally, paper is rarely uniform at the microscopic scale, so Optar utilizes a forward error-correcting coding scheme to cater for a little irregularity in both printing and scanning.

The error-correcting scheme selected was an Extended Golay code (24, 12, 8),  which, interestingly, was also used for image transmission by the NASA Voyager 1 and 2 missions. In information theory terms, this scheme has a minimum Hamming Distance of 8, giving detection of up to seven bit errors. This Golay code implementation is capable of correcting three-bit errors in each 24-bit block, with 12 bits available for payload. That’s what the numbers in those brackets mean.

Another interesting problem is paper stretch during printing. A laser printer works by feeding the paper around rollers, some of which are heated. As a printer wears or gets dirty, the friction coefficient along the rollers can vary, leading to twisting and stretching of the paper during the printing process. Water absorbed by the paper can also lead to distortion. To compensate for these effects, Optar regularly inserts calibration targets throughout the bit image, which are used to locally resynchronize the decoding process as the image is processed. This is roughly similar to how the alignment patterns work within larger QR codes. Finally, similar to the position detection targets (those square bits) in QR codes, Optar uses a two-pixel-wide border around the bit image. The border is used to align to the corners well enough to locate the rows of bits to be decoded.

In the distant past of last week, we covered a similar project that uses QR codes. This got us thinking about how QR codes work, and even if encoding capacity can be increased using more colors than just black and white?

Thanks to [Petr] for the tip!

Back Up Your Data On Paper With Lots Of QR Codes

QR codes are used just about everywhere now, for checking into venues, ordering food, or just plain old advertising. But what about data storage? It’s hardly efficient, but if you want to store your files in a ridiculous paper format—there’s a way to do that, too!

QR-Backup was developed by [za3k], and is currently available as a command-line Linux tool only. It takes a file or files, and turns them into a “paper backup”—a black-and white PDF file full of QR codes that’s ready to print. That’s legitimately the whole deal—you run the code, generate the PDF, then print the file. That piece of paper is now your backup. Naturally, qr-backup works in reverse, too. You can use a scanner or webcam to recover your files from the printed page.

Currently, it achieves a storage density of 3KB/page, and [za3k] says backups of text in the single-digit megabyte range are “practical.” You can alternatively print smaller, denser codes for up to 130 KB/page.

Is it something you’ll ever likely need? No. Is it super neat and kind of funny? Yes, very much so.

We’ve seen some other neat uses for QR codes before, too—like this printer that turns digital menus into paper ones. If you’ve got your own nifty uses for these attractive squares, let us know!