Using motion detectors and an Arduino you can trigger lights, fans, or even an pneumatically controlled cleaver-wielding clown to help add your house to the “if you dare” list. There are ...

It is likely that many of us will at some time have experimented with motion detectors ... as to its mechanism. He can only make it work on the Arduino, other boards with ADCs don’t cut it.

We’re still not sure exactly how [connornishijima]’s motion detector works ... is (so its noise can be filtered out), and a final value that tells the Arduino how long to average values ...