Lesson 27 Sound SensorΒΆ



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.


  • 1 * SunFounder Uno board

  • 1 * USB data cable

  • 1 * Sound Sensor module

  • 1 * 3-Pin anti-reverse cable


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


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.