If you have spent any time in front of a television, late at night, at any point in the last few decades of the 20th century, you can very likely sing the jingle for The Clapper, a sound-activated electrical switch. Maybe you even had one. Or maybe you have one still. It turns out that The Clapper—used to control the electrical power to any device plugged into it when it detects a user clapping—is still on the market. In fact, it’s currently ranked number four among Amazon’s best-selling home-automation devices.
However, The Clapper recently got a new competitor: the Knocki. Instead of responding to sounds, the Knocki uses an accelerometer to detect vibrations, transmitted via a person knocking on a wall or countertop near the device. A single knock awakens the unit, which then listens for one of several preset patterns that the user sets up via the Knocki app for iOS and Android smartphones and tablets, or at the Knocki website. An algorithm running on the device’s microcontroller interprets the knocking pattern before triggering the command to which it was matched when the user initiated the device. “Vibrations that are irregular won’t trigger Knocki to do anything,” says Jake Boshernitzan, a co-founder of Texas-based Swan Solutions, Knocki’s creator. “So you don’t have to worry about a heavy truck hitting a pot hole in the street or kids banging on the kitchen table.”Read more