Sound signal analog signal not affected by actual sound...

Other Hardware Sensors
1

So I have a sound sensor and it works fine...except that analog signals aren't affected by sound. ie: Room is quiet, the led of the sensor isn't receiving sound. If I blast music the sensor led lights up, but the analog signal stays the same (240~250 ish). Any ideas on how to get it working? Specifications and code are below.

int Led = 12 ;   
int Sound = A0;   
int val = 0;    

void setup ()
{
  Serial.begin(9600);
  pinMode (Led, OUTPUT) ;
  pinMode (Sound, INPUT) ;
}
void loop ()
{
  val = analogRead(Sound);
  Serial.println(val);
  delay(100);
}

Sound sensor: KY-038 (the one with 4 pins)
Board: Arduino UNO

If I missed any info just tell me; thanks in advance :slight_smile:

2

In looking at the schematic the pot does nothing but set the level for the comparator. That sets the threshold voltage for the digital output. It has no effect on the analog output.
The analog output is the sound output from the electret microphone. There is no amplification nor buffering.
The levels will be in the millivolt range, not suitable to be read with the analog input. If you want to use the microphone analog output you will need to purchase or make a pre-amplifier. There are many circuits available on line.
This is where I found the schematic: http://arduinolearning.com/wp-content/uploads/2018/07/KY_038_Microphone_sound_sensor_module.png

3

Oh, so I need a pre amplifier? That sounds scary. :slight_smile:

If you can, may you simplify further? Thanks!

4
5

Idahowalker:
Small Microphone Sound Detection Module KY-038 in Arduino - Iotguider

That isn't what I'm aiming to understand, but hey! The more you know! Thanks for the response.