A “Clapper” is a device that will turn on or off an AC appliance that is plugged into it, such as a lamp or fan when it “hears” you clap twice in approximate succession.
Pete has built a Clever Clapper with various task. If user claps twice within one second, the circuit toggles the lamp output. On becomes off and vice versa. If user clap three times within one second, the lamps begin dimming up and down via PWM until a fourth clap is detected or a one minute timeout occurs, whichever comes first. The brightness value is then stored and restored for subsequent toggling of the lights on/off with the two clap event. The project also has a relay output to turn on and off the moon lamp. To trigger this relay, user shines a laser beam at the circuit to toggle it. Laser beams begets moon beams.
The project uses electret mic to capture signal, LM358 Op-amp for amplification and comparator, ATtiny2313 as PWM generator and control relay. If you want to build this project you can download firmware and schematic here