RFID From First Principles And Saving A Cat

November 23, 2024 by Dan Maloney 5 Comments

[Dale Cook] has cats, and as he readily admits, cats are jerks. We’d use stronger language than that, but either way it became a significant impediment to making progress with an RFID-based sensor to allow his cats access to their litterbox. Luckily, though, he was able to salvage the project enough to give a great talk on RFID from first principles and learn about a potentially tragic mistake.

If you don’t have 20 minutes to spare for the video below, the quick summary is that [Dale]’s cats are each chipped with an RFID tag using the FDX-B protocol. He figured he’d be able to build a scanner to open the door to their ~~playpen~~ litterbox, but alas, the read range on the chip and the aforementioned attitude problems foiled that plan. He kept plugging away, though, to better understand RFID and the electronics that make it work.

To that end, [Dale] rolled his own RFID reader pretty much from scratch. He used an Arduino to generate the 134.2-kHz clock signal for the FDX-B chips and to parse the returned data. In between, he built a push-pull driver for the antenna coil and an envelope detector to pull the modulated data off the carrier. He also added a low-pass filter and a comparator to clean up the signal into a nice square wave, which was fed into the Arduino to parse the Differential Manchester-encoded data.

Although he was able to read his cats’ chips with this setup, [Dale] admits it was a long road compared to just buying a Flipper Zero or visiting the vet. But it provided him a look under the covers of RFID, which is worth a lot all by itself. But more importantly, he also discovered that one cat had a chip that returned a code different than what was recorded in the national database. That could have resulted in heartache, and avoiding that is certainly worth the effort too.

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Phoniebox: A Family-Friendly Simple Music Box

October 5, 2024 by Arya Voronova 5 Comments

Ever hear of the Phoniebox project? If not – tune in, that’s a hacker’s project your entire family will appreciate. Phoniebox is a software suite and tutorial for building a jukebox controlled through RFID cards, and it can play audio from a wide variety of sources – music and playlists stored locally, online streams like internet radio stations, Spotify, podcasts of your choice, and so on. It’s super easy to build – get a Raspberry Pi board, connect an NFC reader to it, wire up a pair of speakers, and you’re set. You can assemble a PhonieBox together with your kids over the weekend – and many do.

Want some inspiration, or looking to see what makes Phoniebox so popular? Visit the Phoniebox gallery – it’s endearing to see just how many different versions have been built over the six years of project’s existence. Everyone’s Phoniebox build is different in its own special way – you bring the hardware, Phoniebox brings well-tested software and heaps of inspiration.

You already have a case to house a Phoniebox setup – if you think you don’t, check the gallery, you’ll find that you do. Experiencing a problem? There’s a wealth of troubleshooting advice and tutorials, and a helpful community. Phoniebox is a mature project and its scale is genuinely impressive – build one for your living room, or your hacker’s lair, or your hackerspace. RFID-controlled jukeboxes are a mainstay on Hackaday, so it’s cool to see a project that gives you all the tools to build one.

Swapping Vinyl For Cardboard With This ESP32 Turntable

June 30, 2024 by Bryan Cockfield 15 Comments

Cardboard is a surprisingly durable material, especially in its corrugated form. It’s extremely lightweight for its strength, is easy to work, can be folded and formed into almost any shape, is incredibly inexpensive, and when it has done its duty it can be recycled back into more paper. For these reasons, it’s often used in packaging material but it can be used to build all kinds of things outside of ensuring that products arrive at their locations safely. This working cardboard record player is one example.

While the turntable doesn’t have working records in the sense that the music is etched into them like vinyl, each has its own RFID chip embedded that allows the ESP32 in the turntable’s body to identify them. Each record corresponds to a song stored on an SD card that instructs the ESP32 to play the appropriate song. It also takes care of spinning the record itself with a small stepper motor. There are a few other details on this build that tie it together too, including a movable needle arm held on with a magnet and a volume slider.

As far as a building material goes, cardboard is fairly underrated in our opinion. Besides small projects like this turntable, we’ve also seen it work as the foundation for a computer, and it even has the strength and durability to be built into a wall or even used as shelving material. And, of course, it’s a great material to use when prototyping new designs.

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Paperless RFID Tags Are Carbon-Based

October 28, 2023 by Kristina Panos 16 Comments

RFID tags are great little pieces of technology, but unfortunately, the combination of paper, metal, and silicon means they are as bad as some modern pregnancy tests — single-use electronic devices that can’t be recycled.

A team of design program graduates from London’s Royal College of Art aim to change that. They’ve devised a mostly-paper RFID tag that’s as safe to recycle as a piece of paper with a pencil doodle on it.

The team’s startup, PulpaTronics have created a design that uses paper as its only material. The circuitry is marked on the paper with a laser set to low power, which doesn’t burn or cut the paper, but instead changes to composition to be conductive.

PulpaTronics were also able to create a chip-less RFID tag much the same way, using a pattern of concentric circles to convey information. The company estimates that these tags will reduce carbon dioxide emissions by 70%, when compared with traditional RFID tags. They’ll also cost about half as much.

RFID is used in many industries, but it’s also great for hacking. Here’s an 8-track player that harnesses the power of RFID tags to play songs off of an SD card.

Thanks for the tip, [gir.st]!

KaboomBox Is A Firecracker Of A Music Player

October 23, 2023 by Kristina Panos 5 Comments

Ka-chunk. Let’s face it, 8-tracks were not that great. But the players, that’s another story. The Panasonic RQ-830S, aka the dynamite or TNT player is just one of many lovely designs that used to grace the shelves of electronics stores. Hackaday alum [Cameron Coward] came across a non-working model and used it to create the KaboomBox.

Just like before, all [Cameron] has to do is stick a tape in, and music starts playing. But now, instead of using rust on tape, the music is accessed via RFID and lives on an SD card inside the 8-track player.

Power it on, and a tiny LCD screen showing through the track number window first displays the KaboomBox logo, then shows a timer whenever it’s waiting for a tape. And just like before, pushing down on the plunger skips to the next track.

The new guts include a Raspberry Pi Pico and an RFID reader, plus a DF Player Mini to handle the digital-to-analog conversion and amplify the signal, and an SD card to store the music. Now, [Cameron] is only limited by the size of the SD card. Check out the demo video after the break.

We’ve seen all kinds of boomboxen around here, from the lit to the Bluetooth to the payphone variety.

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Bespoke Implants Are Real—if You Put In The Time

September 6, 2023 by Brian McEvoy 23 Comments

A subset of hackers have RFID implants, but there is a limited catalog. When [Miana] looked for a device that would open a secure door at her work, she did not find the implant she needed, even though the lock was susceptible to cloned-chip attacks. Since no one made the implant, she set herself to the task. [Miana] is no stranger to implants, with 26 at the time of her talk at DEFCON31, including a couple of custom glowing ones, but this was her first venture into electronic implants. Or electronics at all. The full video after the break describes the important terms.

The PCB antenna in an RFID circuit must be accurately tuned, which is this project’s crux. Simulators exist to design and test virtual antennas, but they are priced for corporations, not individuals. Even with simulators, you have to know the specifics of your chip, and [Miana] could not buy the bare chips or find a datasheet. She bought a pack of iCLASS cards from the manufacturer and dissolved the PVC with acetone to measure the chip’s capacitance. Later, she found the datasheet and confirmed her readings. There are calculators in lieu of a simulator, so there was enough information to design a PCB and place an order.

The first batch of units can only trigger the base station from one position. To make the second version, [Miana] bought a Vector Network Analyzer to see which frequency the chip and antenna resonated. The solution to making adjustments after printing is to add a capacitor to the circuit, and its size will tune the system. The updated design works so a populated board is coated and implanted, and you can see an animated loop of [Miana] opening the lock with her bare hand.

Biohacking can be anything from improving how we read our heart rate to implanting a Raspberry Pi.

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RFID Emulator + E-paper Badge Can Be Programmed With Sound

July 22, 2023 by Donald Papp 9 Comments

In a way, an e-paper display makes an excellent foundation for a reprogrammable RFID card. The display only needs power during a refresh, and 125 kHz RFID tags are passive in the sense that the power for the RFID transaction comes from the reader itself. [Georgi Gerganov] has put those together in the GGtag, an open-source project for a 3.52″ e-paper badge with a trick or two up its sleeve.

One clever function is that it is programmable with sound, a feature built off another project of [Georgi]’s called ggwave, a data-to-sound (and vice-versa) framework that has been ported to just about every hardware platform one cares to imagine — including mobile phones — and can reliably send data through the air.

Transmitting data over sound is limited in throughput but has a number of advantages, not least of which is the huge range of compatible devices. There’s a web-based tool for programming the GGtag with sound available at ggtag.io that will give you a preview and let you hear how it works. The data encoding method gives transmissions a charming beep-boop quality that’s a bit reminiscent of an analog modem handshake. GGtag can also be programmed over USB serial, a faster (but somewhat less exciting) option.

The project’s GitHub repository contains GGtag’s code and technical details, and the CrowdSupply project is in the works for anyone who would prefer to buy one once they become available.