Using an Arduino Uno and a servo motor, hacker “Cliptwings” came up with a surprise for treasure hunters!
Geocaching is a game where amateur adventurers find caches in different locations using a GPS receiver. Though this can be a fun way to get outside, once you find the storage box, the challenge is pretty much over. Cliptwings decided to take things in a different direction, and made his cache—which importantly contains a battery on the outside—lock until the retrieving party solves a hangman game.
Once this Arduino-based puzzle is solved, the gadget unlocks with a small servo, revealing the contents inside, most likely a logbook!
The number of this geocache is GC72AFD. The object of the cache is to play and win a game of hangman in order to open the container. An Arduino is used to store five random words. The player uses a knob to turn to a letter, then presses a button to see if it is contained in the word. When the player gets all the words correct, the box opens. If too many wrong words are guessed, access is denied and the box remains locked.
You can find more info on this device in the video below, or check out Dan Wagoner’s hangmanduino code, a modified version of which powers this box!