If your pastimes include fiddling with microcontrollers, then you’ve
probably already experimented with sensing light, temperature,
humidity, infrared, touch capacitance, and so forth. Have you ever
considered brewing up a circuit that will respond to sound?
34 September 2013
BUILD IT YOURSELF
By Thomas Henry
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This is a fun project with lots of unusual applications in the areas of home security and remote control. For
example, the module to be described here could be used
to detect breaking glass, thunder claps, barking dogs, or a
baby crying. It can even detect explosions or gunshots
should you dwell in that sort of environment.
The application I originally had in mind is a little more
down to earth: a circuit that responds intelligently to
handclaps and then controls outboard equipment.
Called the Sonic Sensor, it can directly drive digital
circuits such as CMOS counters or common timers for
more advanced responses. Even better is hooking it up to
a PIC, Arduino, or other processor, and letting the
software work some additional magic.
To keep things concrete for the moment, let’s suppose
our task is simply to sense handclaps and then control
various appliances when detected. You’re probably
already smirking, thinking of cheesy commercial novelties
you’ve seen before. (Heck, I even ran across such a unit in
the close-out bin of a RadioShack some 25 years ago.)