Measuring dBs

Projects Programming
1

I am trying to get a decidable reading using an Arduino Nano but for some reason the dB reading I am getting is no where near the dB reading I am getting using another device. Can anyone point me in the right direction or tell me what I am doing wrong.

Here is my code:

#include <LiquidCrystal.h>

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() 
{

  lcd.begin(16, 2);
}

void loop() 
{
  int sensorValue = analogRead(5);

  double db = 20.0 * log10(sensorValue / 5.0) ;

  lcd.setCursor(0, 0);
  lcd.print("dB Measurement");
  lcd.setCursor(0, 1);
  
  delay(100);
  lcd.print(db);
  lcd.print(" dB        ");
}

I have attached what my breadboard looks like if anyone has any questions on that. The Sound Detector I am using is this one.

dbMeter_bb.png
dbMeter_bb.png1824×1011 203 KB

2

dB is a relative figure that is calculated under very specific condition.

It is not a simple voltage measurement.

Do some research on sound measurement and dBs.

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