Dissecting the Xyloband

A couple of nights ago I went to the Coldplay concert at the Hollywood Bowl. The show was amazing in every respect but what really grabbed my attention were the wristbands they handed out at the gate. These wristbands immediately lit up and began to flicker to the beat of the music, and coordinated with the rest of the lighting coming from the stage (to see it in action take a look at this video). It was truly impressive to say the least!

Being naturally curious as I am I started researching the little gizmo as soon as I got home. I found this great post on Hackaday that already began the discussion I was interested in; how does this thing work? That quickly led me to the interview with it’s creator, Jason Regler, and finally to the actual patent filed with the USPTO (of which I proceeded to read in detail).

My next step was to actually take the thing apart. I’m lucky to have two of these since my fiance Heather joined me on the occasion.

You can see from the picture above that it is powered by three 3V batteries. The two CR2016 batteries are stacked on the back side of the board while the CR2032 is attached to the front. The circuitry itself seems moderately complex with only two ICs and a number of resistors. The most visible IC is on the bottom left is an Si4313 RF receiver from Silicon Labs. This RF receiver runs in the 240-960 Mhz range. The second IC that is partially visible from underneath the battery clamp appears to be the C8051F980 Microcontroller (MCU), also from Silicon Labs.

And for good measure here is a shot of the back of the circuit board.

It’s a very cool gadget. As I dig a little deeper I hope to be able to turn this thing on at my own will, preferably without Charlie Brown’s help.


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  • http://mpinner.com/ @mpinner

    it seems to me one battery is for the micro and radio, while the other two are for the leds.  Let’s see some real photos please. try using macro.

  • Dave

    My wristband’s CPU is an C8051F717 from Silicon Labs.   A datasheet is available here: http://www.silabs.com/products/mcu/capacitivesense/Pages/C8051F7xx.aspx (click on “Product Matrix” tab and scroll down for the F717)

  • Jerrad

    Its a signal centered on 869.5 mhz. I think someone who is RF savvy (ham hacker perhaps?) needs to desperately either get some RF  recieving gear in the vicinity of the next concert that hosts one of these or someone needs to bring an old one of these bands along and do a pin trace of the RF chip.

    I seriously seriously doubt that the transmitter the company is using is using any sort of encryption, once we know the schema of the signals they should be pretty easy to duplicate.

  • Thomas Dejanovic

    There is a second chip on the device with the numbers F980, BR7Z, 234+ the package is a 20 pin package with (starting from pin 1) 5 pins, 6 pins, 5 pins and 4 pins on each side. The crystal on the one I have is 30.0MHz.

  • Elias