soundSensor.ino

#include "arduinoFFT.h"
 
#define SAMPLES 128            
#define SAMPLING_FREQUENCY 2048 
 
arduinoFFT FFT = arduinoFFT();
 
unsigned int samplingPeriod;
unsigned long microSeconds;
 
double vReal[SAMPLES]; 
double vImag[SAMPLES]; 
 
void setup() 
{
    Serial.begin(115200); 
    samplingPeriod = round(1000000*(1.0/SAMPLING_FREQUENCY)); 
}
 
void loop() 
{  

    for(int i=0; i<SAMPLES; i++)
    {
        microSeconds = micros();   
     
        vReal[i] = analogRead(0); 
        vImag[i] = 0; 

       
        while(micros() < (microSeconds + samplingPeriod))
        {
          //do nothing
        }
    }
 
    /Perform FFT on samples/
    FFT.Windowing(vReal, SAMPLES, FFT_WIN_TYP_HAMMING, FFT_FORWARD);
    FFT.Compute(vReal, vImag, SAMPLES, FFT_FORWARD);
    FFT.ComplexToMagnitude(vReal, vImag, SAMPLES);


    double peak = FFT.MajorPeak(vReal, SAMPLES, SAMPLING_FREQUENCY);
    Serial.println(peak);     //most dominant frequency.
    if (peak > 650 && < 1500 && isCNN() || isCNN()){
        Serial.println("Ambulance Detected");
    }

bool isCNN(){
    return true; //placeholder
}