Search My Blog

Saturday, November 19, 2011

Hacking cheap RFID readers | theTransistor

Hacking cheap RFID readers

RFID readers on prototype supply places are expensive. There are many cool applications for the technology, but cheap readers that include documentation and a standard interface are impossible to find.

I decided to confront this problem. I found and ordered a cheap 125kHz reader off  eBay for around ten bucks.

The interface of the reader was usb. You’d plug it into your computer, it’d identify itself as a USB keyboard, and scanned tags would be typed out into a text editor.  my hope was to locate the IC doing the initial decoding, and tap into it. Simple enough right?

When the reader arrived I verified that it indeed worked via usb (it did), then I promptly disassembled it.


I Googled the specs on the components, but unsurprisingly I was unable  to find the datasheet for the chip doing the actual reading.  There were, however, some breakout pins. I was hopeful the hard work was already done, and this was just a generic board. Testing with a volt meter revealed that two were for power (5v, gnd).

Now, I knew what I was looking for, a 10 digit numeric code. What I didn’t know was the protocol being used, and it what variation. I located what I believed was the TX pin (assuming it was UART) by poking around with the RX of an FTDI serial adapter and RealTerm (best serial debugging program imho) to try and get some data.


I didn’t seem to be getting anything usable, but at least each tag was consistent. I assumed the issue was with the settings, however after messing with it for quite a while, I still hadn’t made much progress. I decided this was the perfect excuse for ordering in something I had been wanting to get; the Open Logic Sniffer from dangerous prototypes.  It’s kind of like an oscilloscope but records the data as well.

After it finally arrived, I connected it up, downloaded the software, and started collecting data.


Hacking cheap RFID readers
Getting useful data from a dirt cheap RFID reader - Hack a Day
Hacking cheap RFID readers | theTransistor
ReaderDemo.pde - Google Docs

News 11-19-11
Getting useful data from a dirt cheap RFID reader - Hack a Day
Linux Today - How To Use pfSense To Load Balance Your Web Servers
Linux Today - Apache moves Geronimo to OSGi base
Pushing FPGA config files via serial using ‘cat’ - Hack a Day
Nuclear Taco helmet measures reaction to spicy food - Hack a Day
BBC News - Neutrino experiment repeat at Cern finds same result
Rumor: Galaxy Nexus U.S. Launch is December 8? | News & Opinion |
Cyberattack | SCADA | Illinois | water utility | The Daily Caller
iTunes Match arrives, as does a new Apple board member | Apple Talk - CNET News
Qaddafi Son Seif al-Islam Is Captured in Libya -
Obama and Wen Jiabao of China Talk at Asian Meeting -

No comments: