sketch_dec17c.ino

#include <arduinoFFT.h>

#define sensorPin A1
#define REDPIN 3
#define BLUEPIN 6
#define GREENPIN 5

#define SAMPLES 64             //Must be a power of 2
#define SAMPLING_FREQUENCY 1000 //Hz, must be less than 10000 due to ADC

#define Rrange 12 // SAMPLES/3 (more or less)
#define Grange 6
#define Brange 13 
 
arduinoFFT FFT = arduinoFFT();
 
unsigned int sampling_period_us;
unsigned long microseconds; // current time since the Arduino board started 
 
double vReal[SAMPLES];
double vImag[SAMPLES];

double Rmodule = 0;
double Gmodule = 0;
double Bmodule = 0;

int Rvalue = 0;
int Gvalue = 0;
int Bvalue = 0;

void setup() {
  Serial.begin(115200); // open the serial port at 115200 bps:
  sampling_period_us = round(1000000*(1.0/SAMPLING_FREQUENCY));
  
  pinMode(sensorPin, INPUT);
  pinMode(REDPIN, OUTPUT);
  pinMode(GREENPIN, OUTPUT);
  pinMode(BLUEPIN, OUTPUT);
}

void loop() {/*SAMPLING*/

  for(int i=0; i<SAMPLES; i++)
  {
    microseconds = micros(); //Overflows after around 70 minutes
    vReal[i] = analogRead(sensorPin) - 508; // 508 is silence value by default (can be different on other hardware)
    vImag[i] = 0;

    // remove interferences
    if(vReal[i] >= -2 && vReal[i] <= 2) { 
      vReal[i] = 0;
    }
    
    // We take sampling_period_us microseconds to read the next sample
    while(micros() < (microseconds + sampling_period_us)) { 
    }
     
  }
  /*FFT*/
   
   FFT.Windowing(vReal, SAMPLES, FFT_WIN_TYP_HAMMING, FFT_FORWARD);
   FFT.Compute(vReal, vImag, SAMPLES, FFT_FORWARD);
   FFT.ComplexToMagnitude(vReal, vImag, SAMPLES);
   
   Rvalue = 0;
   Gvalue = 0;
   Bvalue = 0;   
   
   Rmodule = 0;
   Gmodule = 0;
   Bmodule = 0;
   
   /* MODULES of the frequency vectors computed */
   for(int i=1; i < SAMPLES/2; i++)
   {
    double a = vReal[i] * 2;//pow(vReal[i], 2);
    double b = vImag[i] * 2;//pow(vImag[i], 2); // Now we assign each frequency value to its corresponding light range:
    if(i <= Rrange) Rmodule += sqrt(a + b);
    else if(i >= (Rrange+1) && i <= (Rrange+Grange)) Gmodule += sqrt(a + b);
    else Bmodule += sqrt(a + b);
  }

  // Mean values of the modules of each interval:
  //Rmodule /= Rrange; 
  //Gmodule /= Grange;
  //Bmodule /= Brange;/* Giving more INTENSITY to the most DOMINANT frequencies (and reducing the rest):*/
  /*if((Rmodule > Gmodule) && (Gmodule > Bmodule)){
    Rmodule *= 1.5; 
    Gmodule *= 0.5;
    Bmodule *= 0.5;
    }
   else if((Bmodule > Rmodule)&& (Bmodule > Gmodule)){
    Bmodule *= 1.5;
    Gmodule *= 0.2;
    Rmodule *= 0.2;
    }
   else if((Gmodule > Bmodule) && (Gmodule > Rmodule)){
    Gmodule *= 1.5;
    Rmodule *= 0.2;
    Bmodule *= 0.2;
  }  */
    
  Rvalue = 255 * convBrightness(Rmodule);
  Gvalue = 255 * convBrightness(Gmodule);
  Bvalue = 255 * convBrightness(Bmodule); 

  
  if(Rvalue > 140 && Gvalue > 140 && Bvalue > 140) {
    Serial.print("HIGH ");
    Serial.println(Bvalue);
    analogWrite(BLUEPIN, Bvalue * 1.6);
    analogWrite(REDPIN, Rvalue / 1.8);
    analogWrite(GREENPIN, Gvalue / 1.8);
  }
  else if ((Rvalue < 90 && Gvalue < 90 && Bvalue < 90) && (Rvalue > 3 && Gvalue > 3 && Bvalue > 3)) {
    Serial.print("LOW ");
    Serial.println(Rvalue);
    analogWrite(REDPIN, Rvalue / 1.5);
    analogWrite(GREENPIN, Gvalue / 1.5);
    analogWrite(BLUEPIN, Bvalue / 1.5);
  }
  else {
    //Serial.print("Common ");
    //Serial.println(Rvalue);
    analogWrite(REDPIN, Rvalue); // try analog
    analogWrite(GREENPIN, Gvalue);
    analogWrite(BLUEPIN, Bvalue); 
  }
  
  Rvalue = 0;
  Gvalue = 0;
  Bvalue = 0;
  
  delay(25);
 }
 
 double convBrightness(double b) {
  double c = b / 400; // The maximun intensity value in theory is 31713 (but we are never having the volume that high)
  if( c < 0.2 ) c = 0;
  else if(c > 1) c = 1.00;  return c;
}