Yes, geocaching is still live and people enjoy this activity. GPS (or other) accessible to anyone who have at least a smart-phone. The idea is simple – you need to find a cache according to GPS coordinates. Usually this is hidden storage box with log book with sometimes additional treat. In order to make things more challenging, Cliptwings constructed a puzzle box powered by Arduino.
The puzzle is a hangman game which has to be played and won in order to open the box. Controls are pretty simple – by turning knob you can select a letter and with single button you enter it. Arduino generates five random words to be guessed, and if most of them are not guessed – box remains locked. To in safe side, battery is attached on the outside and whole setup is enclosed in waterproof plastic box. If you find hangman game interesting and would like to try it on different projects, you can use Dan Wagoner’s original hangmanduino code for Arduino.