msgeq7 radiate

#include <FastLED.h>

#define LED_PIN     2
#define COLOR_ORDER GRB
#define CHIPSET     WS2812B
#define NUM_LEDS    144

#define BRIGHTNESS  200
#define FRAMES_PER_SECOND 60
#define MSGEQ7_STROBE_PIN 4
#define MSGEQ7_RESET_PIN  5
#define MSGEQ7_LEFT_PIN   A1
#define MSGEQ7_RIGHT_PIN  A0


int filter_min = 100;
int filter_max = 1016;

int prev_value;

int left_value;
int right_value;

float lowPass_audio = 0.18;
uint8_t band;
int left[7];
int right[7];
int mono[7];
int mapped[7];
uint8_t zero;
uint8_t three;
uint8_t six;

int HALF_POS = (NUM_LEDS * 0.5) - 1;


CRGB leds[NUM_LEDS];

void setup() {
  delay(3000); // sanity delay
  FastLED.addLeds<CHIPSET, LED_PIN, COLOR_ORDER>(leds, NUM_LEDS).setCorrection( TypicalLEDStrip );
  FastLED.setBrightness( BRIGHTNESS );
}

void loop()
{
  // Add entropy to random number generator; we use a lot of it.
  // random16_add_entropy( random());
  initializeAudio();
  READ_AUDIO(); // run simulation frame
  radiate();

}

void initializeAudio() {
  pinMode(MSGEQ7_LEFT_PIN, INPUT);
  pinMode(MSGEQ7_RIGHT_PIN, INPUT);
  pinMode(MSGEQ7_RESET_PIN, OUTPUT);
  pinMode(MSGEQ7_STROBE_PIN, OUTPUT);
  digitalWrite(MSGEQ7_RESET_PIN, LOW);
  digitalWrite(MSGEQ7_STROBE_PIN, HIGH);
}

void READ_AUDIO() {

  float left_volume  = 0.0;
  float right_volume = 0.0;
  int mono_volume  = 0;
  float mono_factor  = 0;


  digitalWrite(MSGEQ7_RESET_PIN, HIGH);
  digitalWrite(MSGEQ7_RESET_PIN, LOW);
  delayMicroseconds(1);

  for (int band = 0; band < 7; band++)
  {

    digitalWrite(MSGEQ7_STROBE_PIN, LOW);
    delayMicroseconds(36);

    prev_value  = left[band];
    left_value  = analogRead(MSGEQ7_LEFT_PIN);
    left_value  = constrain(left_value, filter_min, filter_max);
    left_value  = map(left_value, filter_min, filter_max, 0, 255);
    left[band]  = prev_value + (left_value - prev_value) * lowPass_audio;
    left_volume += left[band];


    prev_value   = right[band];
    right_value  = analogRead(MSGEQ7_RIGHT_PIN);
    right_value  = constrain(right_value, filter_min, filter_max);
    right_value  = map(right_value, filter_min, filter_max, 0, 255);
    right[band]  = prev_value + (right_value - prev_value) * lowPass_audio;
    right_volume += right[band];

    digitalWrite(MSGEQ7_STROBE_PIN, HIGH);
    delayMicroseconds(1);

    mono[band]   = (left[band] + right[band]) * 0.5;
    mono_volume += mono[band];

  }

  mono_factor   = float(HALF_POS) / mono_volume;

  for (int band = 0; band < 7; band++)
  {
    mapped[band]    = mono[band] * mono_factor;
  }
}




void radiate() {

  zero  = mono[0];
  three = mono[4];
  six   = mono[6];

  leds[HALF_POS] = CRGB(zero, three, six);

  // high frequencies = blue = FAST SPEED
  EVERY_N_MILLISECONDS(11) {
    for (int i = NUM_LEDS; i > HALF_POS; i--) {
      leds[i].blue = leds[i - 1].blue;
    }
  }

  // mid frequencies = green = MEDIUM SPEED
  EVERY_N_MILLISECONDS(30) {
    for (int i = NUM_LEDS; i > HALF_POS; i--) {
      leds[i].green = leds[i - 1].green;
    }
  }

  // low frequencies = red = SLOW SPEED
  EVERY_N_MILLISECONDS(58) {
    for (int i = NUM_LEDS; i > HALF_POS; i--) {
      leds[i].red = leds[i - 1].red;
    }
  }

  // for mirroring to the other half of the strip
  for (int i = NUM_LEDS; i > HALF_POS; i--) {
    leds[HALF_POS - (i - HALF_POS)] = leds[i - 1];
  }
  FastLED.show();
}