Mikal Hart’s original “reverse geocache” puzzle ended up making a big splash when we first posted about it last October. Now Russ Weeks has produced his own version using an Arduino, an HD44780 display, a servo, and an EM406 GPS. Like Mikal’s version, Russ’s puzzle will only open in one particular location on the surface of the Earth. If it’s elsewhere, pushing the button just gives a readout of the linear distance to the location it wants.

Sean Michael Ragan

Sean Michael Ragan

I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I am a long-time contributor to MAKE magazine and My work has also appeared in ReadyMade, c’t – Magazin für Computertechnik, and The Wall Street Journal.

  • Geocaching

    I love checking out these creative geocaches. Makes me want to build my own.