Although you may not be able to make it to Walt Disney World is year, Dominick Civitano's replica MagicBand reader allows you to bring a bit of that whimsy home for the holidays. The device — first spotted by our Disney obsessed CMO — uses a 3D-printable, mouse-themed housing that conceals an NFC reader and an Arduino Mega, along with a ring of addressable LEDs and a speaker.
When the device is tapped with the proper Disney wristband, the ring lights up just as if you were gaining entry into one of the parks. It then plays a sound via an MP3 microSD card audio module and activates a relay. This can turn on a strand of Christmas lights, though it theory this could be any other gadget to which you want to add a bit of "magic."
More details on the build can be found on Civitano's GitHub page, and the short clips below outline its progression. Instructions are fairly straightforward, yet you will need to program the Arduino to recognize a particular band (or other NFC tag) to have it respond. One might also consider using a “power tail” relay here to avoid working with mains power directly.
While it may be disappointing to some to know that these bands use a simple NFC interface, this fact opens up a vast array of possibilities. Participants, of course, don’t have to be filled in on its secrets!