Arduin MusicLights example

MusicLights.ino

#define OCTAVE 1 //   // Group buckets into octaves
#define OCT_NORM 0 // Don't normalise octave intensities by number of bins
#define FHT_N 256 // set to 256 point fht
#include <FHT.h> // include the library

int noise[] = {90, 125, 147, 143, 128, 123, 104, 89}; //just test output without in silence, and use values from ocatve bins
//int noise[] = {90, 85, 147, 143, 128, 123, 104, 89}; //just test output without in silence, and use values from ocatve bins

// leds
#define R1 PB1
#define R2 PB2
#define R3 PB3

void setup() {
  PORTB = 0; // 1 for hight
  DDRB = (1<<R1)|(1<<R2)|(1<<R3); //1 for output
  Serial.begin(115200); // use the serial port
  TIMSK0 = 0; // turn off timer0 for lower jitter
  //ADCSRA = 0xC5;//0xe5; // set the adc to free running mode
  DIDR0 = 0x39; // turn off the digital input for adc0,3,4,5
}

void loop() {

  // Start of Fourier Transform code; takes input on ADC from mic
  //ADMUX = 0x40; // use adc0
  while (1) { // reduces jitter
    cli();  // UDRE interrupt slows this way down on arduino1.0
    for (int i = 0 ; i < FHT_N ; i++) { // save 256 samples
      /*while (!(ADCSRA & 0x10)); // wait for adc to be ready
      ADCSRA = 0xD5; //0xf5; // restart adc
      byte m = ADCL; // fetch adc data
      byte j = ADCH;
      int k = (j << 8) | m; // form into an int*/
      int k = analogRead(0);
      k -= 0x0200; // form into a signed int
      k <<= 6; // form into a 16b signed int
      fht_input[i] = k; // put real data into bins
    }
    fht_window(); // window the data for better frequency response
    fht_reorder(); // reorder the data before doing the fht
    fht_run(); // process the data in the fht
    fht_mag_octave(); 
    sei();

    // End of Fourier Transform code - output is stored in fht_oct_out[i].

    int fht_noise_adjusted[8];
    int result_octaves[8];
    for (int i = 0; i < 8; i++) {  // For each of the 6 useful octave bins
      
      fht_noise_adjusted[i] = abs(fht_oct_out[i] - noise[i]); // take the pink noise average level out, take the asbolute value to avoid negative numbers
      fht_noise_adjusted[i] = constrain(fht_noise_adjusted[i], 37, 125); // 37 lowpass for noise; 125 high pass doesn't go much higher than this [found by trial and error]
      result_octaves[i] = map(fht_noise_adjusted[i], 37, 125, 0, 255); // map to values 0 - 160, i.e. blue to red on colour spectrum - larger range gives more colour variability [found by trial and error]     
      Serial.print(i);
      Serial.print("\t");
      Serial.println(fht_oct_out[i]);
      /*Serial.print("\t");
      Serial.println(fht_oct_out[i]);*/
      lights(fht_oct_out[i], i);
    }
  }
}

void lights(int con, int octave)
{
  int k1 = analogRead(3);
  k1 = map(k1, 0, 1023, 0, 255);
  int k2 = analogRead(4);
  k2 = map(k2, 0, 1023, 0, 255);
  int k3 = analogRead(5);
  k3 = map(k3, 0, 1023, 0, 255);
  Serial.print("Settings: ");
  Serial.print(k1);
  Serial.print(" ");
  Serial.print(k2);
  Serial.print(" ");
  Serial.println(k3);
  if(octave == 1 && con >= k1) {
    PORTB |= (1<<R3);
  } else if(octave == 1 && con < k1) {
    PORTB &= (0<<R3);
  }
  if(octave == 3 && con >= k2) {
    PORTB |= (1<<R2);  
  } else if(octave == 3 && con < k2) {
    PORTB &= (0<<R2);
  }
  if(octave == 7 && con >= k3) {
    PORTB |= (1<<R1);
  } else if(octave == 7 && con < k3) {
    PORTB &= (0<<R1);
  }
}