[B. Aswinth Raj] wanted to control a VLC player with hand gestures. He turned to two common ultrasonic sensors and Python to do the job. There is also, of course, an Arduino. You can see a video ...

Combining two different kinds of signals could help engineers build prosthetic limbs that better reproduce natural movements, ...

Simply spread your hand over the array and change the angle. Finally, four sensors will also let you detect sweeping gestures that pass over the array, like the swoosh of your hand from one side ...