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Abbaiometro con Raspberry Pi

The Sound Sensor

LM393 based sound sensor

I used a sound sensor based on the LM393 comparator IC. It is advertised as an Arduino KY-038 Microphone Sound Sensor, sold for about 2-5 €.


Connect the + and G pins to 5 VCC and ground respectively: the L1 LED should turn ON. It seems that the sensor works also at 3.3 VCC, beware thet changing the voltage requires a new threshold regulation.

The L2 LED will turn ON when the sound level is above the threshold, which is regulated with the trimmer potentiometer. The POT is a multi turn (may be 10?) potentiometer: turn the mini screw clockwise to be more sensible (to lower the threshold) until the L2 stays ON at normal room noise, then turn the screw counter-clockwise until the LED goes OFF. Clapping your hands you should see the L2 LED blink.

When the sound is above the threshold, a digital high signal is sent across the DO (digital output) pin.

doc/appunti/hardware/raspberrypi_abbaiometro.txt · Last modified: 2015/12/10 15:34 by niccolo