LED demo

#include "FastLED.h"

FASTLED_USING_NAMESPACE
        
// FastLED "100-lines-of-code" demo reel, showing just a few 
// of the kinds of animation patterns you can quickly and easily 
// compose using FastLED.  
//
// This example also shows one easy way to define multiple 
// animations patterns and have them automatically rotate.
//
// -Mark Kriegsman, December 2014
        
#if defined(FASTLED_VERSION) && (FASTLED_VERSION < 3001000)
#warning "Requires FastLED 3.1 or later; check github for latest code."
#endif

#define DATA_PIN    6
#define DATA_PIN2    5
#define LED_TYPE    WS2812B
#define COLOR_ORDER GRB

//***EDIT CODE AREA 
// NUM_LEDS - how many LEDs are in your strip?
#define NUM_LEDS 20
// TRAIL_FADE - Range is 0-255 0 won't fade, 20 fades quickly, 255 instant off.
#define TRAIL_FADE 5
// TRAIL_SPEED - how quickly the trail moves, range is 0-255. 0-really slow, 50-quick, 255 is light speed
#define TRAIL_SPEED 20
// Uses HSVC color wheel, 0-red, 48-yellow, 80-green, 128-teal, 170-blue, 210-purple and 255 is back to red
#define TRAIL_COLOR 0
// BRIGHTNESS - 255 is full bright, 0 is off
#define BRIGHTNESS 255
//****END EDIT CODE AREA


#define FRAMES_PER_SECOND  120

CRGB leds[NUM_LEDS];

void setup() {
  delay(3000); // 3 second delay for recovery
  
  // tell FastLED about the LED strip configuration
  FastLED.addLeds(leds, NUM_LEDS).setCorrection(TypicalLEDStrip);
  FastLED.addLeds(leds, NUM_LEDS).setCorrection(TypicalLEDStrip);

  // set master brightness control
  FastLED.setBrightness(BRIGHTNESS);
}


// List of patterns to cycle through.  Each is defined as a separate function below.
typedef void (*SimplePatternList[])();
SimplePatternList gPatterns = { sinelon_mod };

uint8_t gCurrentPatternNumber = 0; // Index number of which pattern is current
uint8_t gHue = 0; // rotating "base color" used by many of the patterns
  
void loop()
{
  // Call the current pattern function once, updating the 'leds' array
  gPatterns[gCurrentPatternNumber]();

  // send the 'leds' array out to the actual LED strip
  FastLED.show();  
  // insert a delay to keep the framerate modest
  FastLED.delay(1000/FRAMES_PER_SECOND); 

  // do some periodic updates
  EVERY_N_MILLISECONDS( 20 ) { gHue++; } // slowly cycle the "base color" through the rainbow
  EVERY_N_SECONDS( 10 ) { nextPattern(); } // change patterns periodically
}

#define ARRAY_SIZE(A) (sizeof(A) / sizeof((A)[0]))

void nextPattern()
{
  // add one to the current pattern number, and wrap around at the end
  gCurrentPatternNumber = (gCurrentPatternNumber + 1) % ARRAY_SIZE( gPatterns);
}


void sinelon_mod()
{
  // a colored dot sweeping back and forth, with fading trails
  fadeToBlackBy( leds, NUM_LEDS, TRAIL_FADE );
  int pos = beatsin16( TRAIL_SPEED, 0, NUM_LEDS-1 );
  leds[pos] += CHSV( TRAIL_COLOR, 255, 255);
}