rfid

185 Articles

Long-Range RFID With Feedback

January 17, 2019 by 24 Comments

Not long ago, we published an article about researchers adding sensor data to passive RFID tags, and a comment from a reader turned our heads to a consumer/maker version which anyone can start using right away (PDF). If you’re catching up, passive RFID technology is behind the key fobs and stickers which don’t need power, just proximity to the reader’s antenna. This is a much “hackier” version that works with discrete signals instead of analog ones. It will not however require writing a new library and programming new tags from the ground up just for the user to get started, so there is that trade-off. Sparkfun offers a UHF reader which can simultaneously monitor 25 of the UHF tags shown in this paper.

To construct one of these enhanced tags, the antenna trace is broken and then routed through a switching device such as a glass-break sensor, temperature limit switch, doorbell, or light sensor. Whenever continuity is restored the tag will happily send back its pre-programmed data, and the reader will acknowledge that somewhere one of the tags is seeing some activity. Nothing says this could not be applied to inexpensive RFID readers should you just want a temperature warning for your gecko terrarium or light sensor to your greenhouse‘s sealed controller.

Thank you, [Mike Massen], for your tip on RFID Doing More Than ID.

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Sniffing RFID Readers With A Piece Of Paper

November 28, 2018 by 17 Comments

We feature plenty of printed projects here on Hackaday, though they tend to be of the three dimensional type thanks to the proliferation of affordable 3D printers. But in this case, [Milosch Meriac] has managed to put together a printable design that’s not only a very cool hack, but is made up of a scant two dimensions. His creation, which could perhaps be considered something of an interactive circuit diagram, allows anyone with a paper printer and a few passive components to make a functional low-frequency RFID sniffer.

[Milosch] tells us the goal of the project is to lower the barrier for experimenting with the RFID technology that’s increasingly part of our everyday lives. Rather than having to use something expensive and complicated such as an oscilloscope, experimenters can simply plug their DIY RFID sniffer into their computer’s line-in jack and explore the produced waveform with open source tools.

To create a paper RFID sniffer, you start by printing the image out on a thick piece of paper, like card stock. You then apply foil tape where indicated to serve as traces in this makeshift PCB, and start soldering on the components as described in the text. [Milosch] says the assembly procedure is so simple even a kid can do it, and the total cost of each assembled sniffer is literally pennies; making this an excellent project for schools or really any large group.

If you want to play it safe the sniffer can be connected to a USB sound card rather than your machine’s primary sound hardware, and still come in dirt cheap. [Milosch] stops short of explaining the software side of things in this particular project, but any tool which can use input from the sound card as a makeshift oscilloscope should be a good start.

In the past we’ve seen [Milosch] perform low frequency RFID sniffing through the sound card with the powerful baudline tool, but if you want a little more capable hardware, we can point you in the right direction.

ESP8266 Keeps Tabs On The Kid’s Tablets

July 5, 2018 by 24 Comments

Assuming you have a child and it’s no longer womb-bound, there’s a fairly high chance they’ve already had some experience with the glowing beauty that is the LCD display; babies of only a few months old are often given a tablet or smartphone to keep them occupied. But as the child gets to the age where they are capable of going outside or doing something more constructive, staring slack-jawed and wide-eyed at their tablet becomes a concern for many parents.

[Richard Garsthagen] is one such parent. He wanted a way to monitor and control how much time his children were using their iPad, so he came up with an automated system based on the ESP8266. Not only does it keep track of how long the tablet is being used, it even includes a reward system which allows the parent to add extra usage time for good behavior.

At the most basic level, the device is a sort of “holster” for the child’s tablet. When the tablet is placed in the slot, it presses a microswitch at the bottom of the cavity which stops the timer. When the switch is open, the LED display on the front of the device counts down, and the ESP8266 pushes notifications about remaining time to the child’s device via IFTTT.

Time can be added to the clock by way of RFID cards. The cards are given out as a reward for good behavior, completion of chores, etc. The child only needs to pass the card in front of the system to redeem its value. Once the card has been “spent”, the parent can reset it with their own special card.

It’s a very slick setup, making perfect use of the ESP8266. Reading the RFID cards, updating the timer, and using IFTTT’s API keeps the little board quite busy; [Richard] says it’s completely maxed out.

You might be wondering what happens when the clock reaches zero. Well, according to the video after the break…nothing. Once the time runs out, a notification simply pops up on the tablet telling them to put it away. Some might see this as a fault, but presumably it’s the part of the system where humans take over the parenting and give the ESP8266 a rest.

This isn’t the first time we’ve seen a microcontroller used to get the little hackers on schedule. At least (so far) none of them have gone full Black Mirror and started tracking when the kiddos are watching it.

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Ask Hackaday: What Is The Future Of Implanted Electronics?

June 7, 2018 by 138 Comments

Biohacking is the new frontier. In just a few years, millions of people will have implanted RFID chips under the skin between their thumb and index finger. Already, thousands of people in Sweden have chipped themselves to make their daily lives easier. With a tiny electronic implant, Swedish rail passengers can pay their train ticket, and it goes without saying how convenient opening an RFID lock is without having to pull out your wallet.

That said, embedding RFID chips under the skin has been around for decades; my thirteen-year-old cat has had a chip since he was a kitten. Despite being around for a very, very long time, modern-day cyborgs are rare. The fact that only thousands of people are using chips on a train is a newsworthy event. There simply aren’t many people who would find the convenience of opening locks with a wave of a hand worth the effort of getting chipped.

Why hasn’t the most popular example of biohacking caught on? Why aren’t more people getting chipped? Is it because no one wants to be branded with the Mark of the Beast? Are the reasons for a dearth of biohacking more subtle? That’s what we’re here to find out, so we’re asking you: what is the future of implanted electronics?

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Held Captive By Arduino And Multiple RFID Readers

May 13, 2018 by 18 Comments

If you’re the kind of person who has friends, and/or leaves the confines of the basement from time to time, we hear that these “Escape Rooms” are all the rage. Basically you get locked into a room with a couple other people and have to solve various problems and puzzles until you’ve finally made enough progress that they let you out. Which actually sounds a lot like the working conditions here at Hackaday HQ, except they occasionally slip some pizza rolls under the door for us which is nice.

Whichever side you find yourself on in one of these lighthearted hostage situations, knowledge of this multi-tag RFID lock created by [Annaane] may come in handy. By connecting multiple MFRC522 RFID readers to an Arduino Uno, she’s come up with a method of triggering a device (like an electronic door lock) only when the appropriate combination of RFID tags have been arranged. With a little imagination, this allows for some very complex puzzle scenarios which are sure to keep your prisoners enthralled until you can lower the lotion down to them.

Her code allows you to configure the type and number of RFID cards required to trigger one of the Arduino’s digital pins, which usually would be connected to a relay to fire off whatever device you want. The Arduino sketch is also setup to give “hints” to the player by way of a status LED: fast blinking let’s you know the tag scanned is wrong, and slow blinking means you don’t have enough scanned in yet.

The video after the break shows some highlights of the build, as well as a quick demonstration of how both the RFID “combination” and manual override can be used to trigger the attached relay.

Hackers do love RFID. Using them for physical access control is a fairly common project around these parts, and we’ve even seen similar setups for the digital realm.

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Long-Range RFID Leaflets

January 19, 2018 by 29 Comments

Pick a card, any card. [Andrew Quitmeyer] and [Madeline Schwartzman] make sure that any card you pick will match their NYC art installation. “Replantment” is an interactive art installation which invites guests to view full-size leaf molds casts from around the world.

A receipt file with leaf images is kept out of range in this art installation. When a viewer selects one, and carries it to the viewing area, an RFID reader tells an Arduino which tag has been detected. Solid-state relays control two recycled clothing conveyors draped with clear curtains. The simple units used to be back-and-forth control but through dead-reckoning, they can present any leaf mold cast front-and-center.

Clothing conveyors from the last century weren’t this smart before, and it begs the question about inventory automation in small businesses or businesses with limited space.

We haven’t seen much long-range RFID, probably because of cost. Ordinary tags have been read at a distance with this portable reader though, and NFC has been transmitted across a room, sort of.

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