Sound reactive comet

sound_coment.ino

#include <FastLED.h>

#define NUM_LEDS  30
#define DATA_PIN   3

const uint8_t g_Brightness = 16;
CRGB g_LEDs[NUM_LEDS];

int  sensorAnalogPin = A0;    // Select the Arduino input pin to accept the Sound Sensor's analog output 
int  sensorDigitalPin = 6;    // Select the Arduino input pin to accept the Sound Sensor's digital output
int  analogValue = 0;         // Define variable to store the analog value coming from the Sound Sensor
int  digitalValue;            // Define variable to store the digital value coming from the Sound Sensor
int  Led13 = 13;              // Define LED port; this is the LED built in to the Arduino (labled L)
                              // When D0 from the Sound Sensor (connnected to pin 7 on the
                              // Arduino) sends High (voltage present), L will light. In practice, you
                              // should see LED13 on the Arduino blink when LED2 on the Sensor is 100% lit.

void setup() {
  Serial.begin(9600);               // The IDE settings for Serial Monitor/Plotter (preferred) must match this speed
  pinMode(sensorDigitalPin,INPUT);  // Define pin 7 as an input port, to accept digital input
  pinMode(Led13,OUTPUT);            // Define LED13 as an output port, to indicate digital trigger reached
  
  FastLED.addLeds<NEOPIXEL, DATA_PIN>(g_LEDs, NUM_LEDS); // intialize LED's with FASTLED
  FastLED.setBrightness(g_Brightness);
  FastLED.clear(true);                                   // still no idea why I do this
}

void loop () {

  analogValue = analogRead(sensorAnalogPin); // Read the value of the analog interface A0 assigned to digitalValue 
  digitalValue=digitalRead(sensorDigitalPin); // Read the value of the digital interface 7 assigned to digitalValue 
  Serial.println(analogValue); // Send the analog value to the serial transmit interface
  
  if(digitalValue==HIGH)      // When the Sound Sensor sends signla, via voltage present, light LED13 (L)'
  {
    digitalWrite(Led13,HIGH);

      for (int j = 0; j < 45; j++) {
        drawComet();  
        FastLED.show();
      }
  }
  else
  {
    digitalWrite(Led13,LOW);
  }
  
  delay(30);                  // Slight pause so that we don't overwhelm the serial interface
  

  
}

void drawComet() {
    const byte fadeAmount = 196;
    const byte cometSize = 2;
    const byte deltaHue = 4;

    static byte hue = HUE_RED;
    static int iDirection = 1;
    static int iPos = 0;

    FastLED.clear(false);

    // switch direction and change color if at end
    iPos += iDirection;
    if (iPos == (NUM_LEDS - cometSize) || iPos == 0) {
        hue += 30;
        iDirection *= -1;
      }
      
    
    for (int i = 0; i < cometSize; i++)
        g_LEDs[iPos + i].setHue(hue);
    
    // Randomly fade the LEDs
    for (int j = 0; j < NUM_LEDS; j++)
        if (random(10) > 5)
            g_LEDs[j] = g_LEDs[j].fadeToBlackBy(fadeAmount);  
  
  }