Using An AVR As An RFID Tag

May 20, 2011 by Brian Benchoff 11 Comments

A few years ago, [Beth] came up with the idea of using an AVR as an RFID tag. She’s gotten sidetracked with a few other projects in the meantime but her idea has surfaced again, this time as a duct tape RFID tag. The build is just four components: 0.1 µF and 1 nF capacitors, an ATtiny85 microcontroller, and 100 turns of 40 AWG magnet wire, all soldered together and placed on a duct tape substrate.

Like most RFID tags, the power is drawn from the reader through the coil, but even in low power versions the ATtiny is only rated down to 1.8 Volts. Since the microcontroller is only getting about 1 Volt from the coil, the clock oscillator of the ATtiny won’t work. This isn’t a problem in this build, because the coil is connected to the the clock input – the 125 kHz coming off the reader provides the clock. Very clever.

Of course, the microcontroller is going to need some firmware to send some bits to the reader, so she used the AVRFID firmware (check out the comments in the source for a great walkthrough) to transmit under the HID protocol, itself a derivative of [Beth]’s earlier work with the EM4102 protocol.

Not only are we impressed with this hack, we’re amazed [Beth] is still perfecting her work more than two years after her first post on the subject. That’s dedication and unbridled cleverness.

Via adafruit

RFID Smart Card Reader

May 17, 2011 by Caleb Kraft 9 Comments

[Navic] wrote in to show us his latest project. This is a portable smart card reader with a nice LCD display. he just happened to have a Basic Stamp 2px, smart card reader, and smart card reader/writer sitting around waiting to be used. What better use than a hand held smart card reader? Tossing the bits together in a nice project enclosure, [Navic] scoured the code available to him and pieced together what he needed. Now, when you slide in a card, you get a nice readout of the data on that pretty blue screen. Unfortunately, if you pull the card before the read is finished, everything just freezes.

You can see the final video after the break, and you can also see some in-progress videos linked in youtube. He asks if he should add the ability to write, and we say YES. Store that data, then write (duplicate) to another device.

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Open Hacker Conference Badge Project Needs Your Help!

April 18, 2011 by Jeff Katz 18 Comments

[Aestetix] writes in to tell us that the OpenAMD (Attendee Meta-Data) project is working on a new revision of their hardware, to be debuted at CCC Camp this fall.

For the uninitiated, OpenAMD combines an Active RFID tracking system with social networking, and is completely open-source. You walk into the conference, put on the OpenAMD badge, and suddenly you can see yourself as a dot moving around on a map. Or you can log into the social networking site, create a profile, and watch as your personal information is pulled into the mesh, which then tells you talks you might like, people you might like, where those people are, and more. There’s even an open API where you can create your own ‘killer’ apps, which may include games or other interesting aggregates of the attendee information.

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RFID Drink System Eliminates The Need For Change

April 4, 2011 by Mike Nathan 61 Comments

popcard_vending_machine

[Avatar-X] snagged a drink vending machine online a few years back, and has been selling drinks to his neighbors ever since. People are always asking him for change, and just the other day he was thirsty and out of change himself. He considered adding an override key so that he could snag free drinks whenever he pleased, but decided to go all out and built a cash card system instead.

He didn’t know how to interface with the machine’s logic board, so after poring over the service manual he consulted with a support rep from the company that manufactured it. Luckily, he was able to get enough information from them to start making some headway. With his friend’s assistance, he was able to figure out which pins on the Bill Validator Interface needed to be shorted in order to simulate the addition of funds.

Using an Arduino with an Ethernet shield, LCD display, and an RFID reader, he had his PopCARD system up and running in no time. Now all his neighbors have to do when they want a drink is swipe their card in front of the machine and hit a button to add funds from their account.

As you can see in the video below it works great, and we’re sure his neighbors are pleased with the improvements he has made.

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RFID-based HTPC Controller Gets A Wireless Refresh

March 20, 2011 by Mike Nathan 4 Comments

RFiDJ_Refresh

[roteno] recently wrote in to let us know that he has completed work on the RFiDJ Refresh, a follow up to his 2009 project, the RFiDJ.

The concept is pretty simple – he has a set of RFID enabled tiles, which contain references to particular online streaming audio stations. He uses these tiles to tune into audio feeds on his HTPC by placing them on a block containing an RFID reader.

His previous implementation had the RFID reader tethered to his HTPC, which didn’t make it all that convenient to use. The newer version utilizes a 433 MHz transmitter/receiver pair in order to communicate with the PC, so it can be used anywhere through out his house. The reader and transmitter were placed in a shadow box picture frame, along with a rechargeable Li-poly battery that powers the whole setup. He also mentions that he has added a tactile interface that allows him to initiate mobile phone calls from the RFiDJ as well.

It’s a nice update to an already great project. We imagine it’s a bit more fun for [roteno] and his guests to tap a coaster on the transmitter box than fumble with a remote to change radio stations on the HTPC, but that’s just us.

Check out the videos below to see his new setup in action.

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Breaking The IClass Security

February 23, 2011 by Mike Szczys 9 Comments

iClass is a popular format of RFID enabled access cards. These are issued to company employees to grant them access to parts of a building via a card reader at each security door. We’ve known for a long time that these access systems are rather weak when it comes to security. But now you can find out just how weak they are and how the security can be cracked. [Milosch Meriac] delved deep into the security protocol for HID iClass devices and has laid out the details in a white paper.

The most invasive part of the process was breaking the copy protection on PIC 18F family of chips in order to read out the firmware that controls card readers. This was done with a USB to serial cable and software that bit-bangs its own implementation of the ICSP protocol. After erasing and attacking several chips (one data block at a time) the original code was read off and patched together. Check out [Milosch’s] talk at 27C3 embedded after the break, and get the code for the ICSP bit banging attacks from the white paper (PDF).

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Electronic Tolling System

February 17, 2011 by Mike Szczys 8 Comments

For us the hardest part of any project is coming up with the seminal idea. Once in a while you just need to cheat by recreating an existing product. That’s what EngineersGarage did with this toll plaza project. If you take a look around the various tabs at the top of that article you’ll see that they’ve used an 8051 microcontroller to bring together a character LCD, RFID reader, and a keypad. From there it’s a slew of coding to add the functionality for reading multiple tags, looking up stored value, and creating a replenishment system. Sure, it’s not really of much use in this form, but it’ll give you something to do with those shiny parts you have sitting around, and it might just lead you down a path to something more meaningful. As usual, there’s a demonstration video of this after the break.

If this doesn’t float your boat, perhaps this other RFID access system is more your thing.

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