New submitter Mathieu Stephan writes "Hello everyone! Some people told me that my latest project might interest you. I'm not sure you publish this kind of projects, but here it goes. Basically, it is a small platform that recognizes whistles in order to switch on/off appliances. It will be obviously more useful for lighting applications: just walk in a room, whistle, and everything comes on. The project is open hardware, and all the details are published on my website." The linked video is worth watching for the hidden-camera footage alone: it would be hard to not keep playing with this sensor.