I want to program a KY037 microphone to measure the ambient sound in dB and every mesaure it makes I will save it in a microSD, including the value of sound and the time in which it took it (this time I haven´t added yet)

I´ve used lots of codes so far but this is what I got now:

#include <SPI.h>
#include <SD.h>

File myFile;

int j;
float voltage, db;

const int sampleWindow = 50; // Sample window width in mS (50 mS = 20Hz)
unsigned int sample;

#define SENSOR_PIN A0
#define CS_PIN 10

// Ejemplo de calibracion (ajustar valores segun mediciones reales)
const float vRef = 5.0; // Voltaje de referencia (valor de alimentación)
const float dbRef = 0.0; // dB a 0 volts (ajustar según micrófono)
const float dbPerVolt = 20.0; // dB por cada volt (ajustar según micrófono)

void setup() {
  pinMode(SENSOR_PIN, INPUT_PULLUP); // Set the signal pin as input
  pinMode(CS_PIN, OUTPUT);
  Serial.begin(115200);

  if (SD.begin()) {
    Serial.println("SD card ready to use");
  } else {
    Serial.println("SD card not ready");
    return;
  }
}

void loop() {
  myFile = SD.open("data.csv", FILE_WRITE);
  unsigned long startMillis = millis(); // Start of sample window

  double peakToPeak = 0; // peak-to-peak level

  double signalMin = 1024; // maximum value
  double signalMax = 0;   // minimum value

  // collect data for 50 ms
  while ((millis() - startMillis) < sampleWindow) {
    sample = analogRead(SENSOR_PIN); // get reading from microphone
    voltage = sample * vRef / 1023.0; // convert reading to voltage
    if (voltage > signalMax) {
      signalMax = voltage; // save just the max levels
    } else if (voltage < signalMin) {
      signalMin = voltage; // save just the min levels
    }
  }

  peakToPeak = signalMax - signalMin;
  // Ejemplo de conversion a dB (ajustar segun calibracion real)
  db = dbRef + dbPerVolt * peakToPeak;

  // Write data to SD card
  if (myFile) {
    Serial.print("PeakToPeak:");
    Serial.print(peakToPeak);
    Serial.print(",");
    Serial.print("Decibels:");
    Serial.println(db);

    myFile.print(String(db));
    myFile.print(",");
    myFile.print(String(millis() / 1000));
    myFile.println();
    myFile.close();
  } else {
    Serial.print("Error opening file.");
  }
}

The problem with this is that with applause that sholud measure over 70-80 dB, it prints a value of 200 or maybe 400 dB.