A Universal RFID key

RFID projects have been pretty prominent recently, ranging from projects here in Instructables, to our local Silicon Chip magazine in Australia publishing a RFID door lock project in their November issue. Even I recently purchased a RFID door lock on eBay for $15 to lock my garage (so my front neighbor could get tools if he wanted to).

We have known that the cheaper RFID technologies were pretty insecure for a number of years. Researchers have demonstrated cloners of all varieties, but simple RFID tags are still being used for access control. Even my current employer uses them.

A while ago, I was looking at Hack A Day, and I saw an amazing project that somebody had made. It was an RFID card with a keypad on it. For the next couple of days, I couldn’t get the image of the card out of my mind; the project reminded me of how much I wanted to build a RFID spoofer myself. The original author didn’t release source code for their project, but they left enough clues that I could follow.

So, in typical fashion, I built my own reader hardware so I could have a look at the data from a card, and created my own version of the Universal RFID key.

The key I made works beautifully both on my garage door, as well as on a number of other readers I tried.

I have decided to publish this, as more people should be aware of the design flaws that are inherent in older RFID implementations, and to allow others to make their own universal key.

Will this key let you into anybodies RFID protected office? Yes it will, assuming a couple of things are true

1) The have to be using 125Khz RFID tags that use the same encoding standard as I have designed this project for, and,
2) You have to have access to the number printed on the back of the tag – with that number, you can simply key it into the Universal RFID key, and it will emulate that tag.

So there you go – I hope you enjoy making this project. – And remember, with great power comes great responsibility!

Here is a link to the full Instructables project – http://www.instructables.com/id/A-Universal-RFID-Key/ Alternately – the relevant source code is available HERE.

Prox Card

Arduino ATMega326 Using the Oscillator pin

I just figured out how to use the oscillator pin of the AtMega328 chip to drive an additional component. I am working on a project that requires a 16Mhz clock to drive other electronics, and figured that the AtMega328 chip there has a 16Mhz crystal connected to it. Sadly the default fuse programming that the Arduino world uses is a ‘low power’ mode where the voltage on the oscillator pin is only about 200mV. If you re-program the fuses, you can put the oscillator into ‘full swing’ mode. Neat!!

The command line I used was:

avrdude -p m328p -c usbtiny -U lfuse:w:0xf7:m -U hfuse:w:0xda:m

Neat!!! Now I can see a beautiful full voltage sinewave on the Oscillator pin.CRO display of new full swing waveform

A Stylophone

I decided to make a Stylophone as a gift for my dad.  I also documented the build process.

It is purely Analog (No micro included) – which is a rarity for me.

Here is the link to the schematic and PCB files.

And if you want, here is the link to the Instructables article for step by step instructions.  I have been careful to make sure that it is fully accessible.

This reminds me of my childhood!!

Update:  Lots of people have been asking for a video showing what it sounds like.  Click HERE to view it on youtube

An Ethernet connected watering system controller

I extended the relay controller design that I put up recently to do the task of being a watering system. Getting the code to fit into an AtMega328 was a bit tricky, I kept having stack overflow problems because my strings were too big.  But it fits!

And it uses a Microchip ENC28J60 ethernet controller.

Full design files are in the Instructables.com article here.

If you want to download the project tree – Here it is.

An Ethernet Relay Controller

As a recent project, I designed a cool relay controller that uses a state machine to control a set of relay outputs based on a user defined program.  The initial task is to operate a set of Christmas lights at Christmas time, but there is nothing stopping me using it for anything I like later on.

The device is configured via a web browser.  I had a lot of fun fitting the web pages into the AtMega368 chip that this device uses.  There is much I can learn about stack frames on tiny devices :-)

The project is published as an instructable, at http://www.instructables.com/id/A-Remotely-Programable-Relay-Controller-Christmas/

I will put full design files up here once I get my head around WordPress.

My Relay controller that uses an Ethernet interface

WordPress Themes