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Reverse Geocache Briefcase Unlocks in the Right Spot | Make:
Check out Flickr user Rumtopf’s fancy take on the reverse geocache box. For those who don’t know, a reverse geocache is a box that unlocks itself when the GPS sensor inside senses that it’s in a specific spot on the globe. Rumtopf used a snazzy doorbell button to wake an Arduino, which checks the GPS and displays the distance from that spot on an LCD. He also used a magnetic child safety lock as a backdoor to access the inside of the briefcase in case of malfunction.