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.
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.
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.
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.
Anyone with more than one cat can tell you that the joy mischief they bring into your life is much more than twice that of a single cat. And if those felines have different dietary needs, you can end up where [Benjamin Krejci] found himself, which resulted in this fancy RFID cat feeder.
For a little backstory, [Ben]’s furry friends [Luna] and [Fermi] have vastly different eating styles, with the former being a grazer and the latter more of a “disordered eater,” to put it politely. [Fermi] tends to eat until she vomits, which is fun, and muscles her pickier sister away from the bowl if there’s anything left in it. [Ben]’s idea was to leverage [Luna]’s existing RFID chip, which he figured would be a breeze. But the vet-inserted chip is designed to be read by a high-power reader directly in contact with the cat’s skin, which made reliably reading the chip a challenge.
Several round of design iteration resulted in the current configuration, with a large antenna coil poised above and behind the food dispenser. [Luna] has no choice but to put the back of her neck and shoulder blades almost directly in contact with the coil, which makes it easier to read the 134.2-kHz chip with a long-distance RFID module. If [Luna]’s chip is found, the lid on the food bowl opens gently and quietly, so as not to spook the mild-mannered cat. The lid stays open as long as [Luna] is in place thanks to some IR sensors, but as soon as she backs out, the lid comes down to keep [Fermi] from gorging herself.
Hats off to [Ben] for working through the problem and coming up with what looks like a fine solution. We suppose he could have tried something easier like weighing the two cats to distinguish between them, but this seems like a cleaner solution to us.
Digital music has made keeping all your tunes with you a lot more convenient, but have we lost something with dematerialization? [Jordi Parra] felt that there was something lacking with the digital music experience and designed a Spotify player with a tactile interface.
Specific playlists are selected via small RFID tags that look like a cross between a MiniDisc and a vinyl record. As this is a prototype, an Arduino reads the RFID tag, but needs a computer to actually play the Spotify playlist. Future iterations could include an integrated speaker and run libspotify to create a self-contained device.
While there is still work to do for a fully seamless experience, we love the details in the industrial design of this project. Clean simple lines and a combination of wood and more modern materials make this feel like a timeless piece of tech. Definitely check out the full photo gallery including shots of the really impressive packaging.
Consumer electronics aimed at young children tend to be quite janky and cheap-looking, and they often have to be to survive the extreme stress-testing normal use in this situation. You could buy a higher quality item intended for normal use, but this carries the risk of burning a hole in the pockets of the parents. To thread the needle on this dilemma for a child’s audiobook player, [Turi] built the Grimmboy for a relative of his.
Taking its name from the Brothers Grimm, the player is able of playing a number of children’s stories and fables in multiple languages, with each physically represented by a small cassette tape likeness with an RFID tag hidden in each one. A tape can be selected and placed in the player, and the Arduino at the center of it will recognize the tag and play the corresponding MP3 file stored locally on an SD card. There are simple controls and all the circuitry to support its lithium battery as well. All of the source code that [Turi] used to build this is available on the project’s GitHub page.