Lesson 27 Sound SensorΒΆ
Introduction
Sound Sensor is a component that receives sound waves and converts them into electrical signals. It detects the sound intensity in ambient environment like a microphone.
Components
1 * SunFounder Uno board
1 * USB data cable
1 * Sound Sensor module
1 * 3-Pin anti-reverse cable
Principle
The sensor has a capacitive electret microphone which is sensitive to sound. Sound waves cause the thin film of the electret to vibrate and then the capacitance changes, thus producing the corresponding changed voltage. Since the voltage change is extremely weak, it needs to be amplified. LM358 here is a power amplifier of 100 times gain. Connect the SIG output pin of the sound sensor to A0 of the SunFounder Uno board. Then you can see the value of sound intensity on Serial Monitor, or display the wave forms on an oscilloscope if you have connected one. The schematic diagram:
Experimental Procedures
Step 1: Build the circuit
Step 2: Open the code file
Step 3: Select correct Board and Port
Step 4: Upload the sketch to the SunFounder Uno board
Code
Now you can see the value of sound intensity on Serial Monitor. When the volume reaches to a certain value, the LED attached to pin 13 on the SunFounder Uno will light up.