Overclocked smartwatch sensor uses vibrations to sense gestures, objects and locations

Just from patterns of motion, your smart devices know when you’re walking, when you’re riding a bike and when you lift your wrist to check the time. But it turns out they can also tell when you snap or make a fist, or whether you’re holding a smartphone or steering wheel. All they have to do is listen a little harder — well, about 100 times harder, actually.