[AJ] and [Brian] are making sure the geocache challenges they set up take some ingenuity to solve. They’ve just rolled out a two-part cache which uses a code hidden in infrared light.

The first part of the cache is a box (the black one on the left) which contains a mysterious hand crank and a smaller box that has a combination lock on it. The second stage is the wooden box on the right. It’s got a hole in the side to receive the hand crank. This connects to the dynamo inside, letting you build up some electricity as it spins. Inside the case you’ll see two red lights blink as the crank is turned, but when you push the button on the outside of the box nothing will happen. That is, unless you’re looking through a camera which can pick up infrared light. The code (710 in this case) is displayed in an array of IR LEDs, and is used to open that combination lock. We wonder if there’s any clues about using a camera or if you have to figure this out on your own.

Don’t miss the video after the break for a full demo of the system.

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