#include <Adafruit_NeoPixel.h>
/*
    Tratto dal sito di Mauro Alfieri
    https://www.mauroalfieri.it/elettronica/neopixel-ring-16led-strandtest.html
*/
 
#define PIN 6
float facteur = random();
int rouge = round(255*facteur);
int vert = rouge;
int bleu = round((255*0,86)*facteur);

int rouge2 = round(255*facteur);
int vert2 = rouge;
int bleu2 = round((255*0,86)*facteur);

Adafruit_NeoPixel strip = Adafruit_NeoPixel(16, PIN, NEO_GRB + NEO_KHZ800);

// Parameter 1 = number of pixels in strip
// Parameter 2 = Arduino pin number (most are valid)
// Parameter 3 = pixel type flags, add together as needed:
// NEO_KHZ800  800 KHz bitstream (most NeoPixel products w/WS2812 LEDs)
// NEO_KHZ400  400 KHz (classic 'v1' (not v2) FLORA pixels, WS2811 drivers)
// NEO_GRB     Pixels are wired for GRB bitstream (most NeoPixel products)
// NEO_RGB     Pixels are wired for RGB bitstream (v1 FLORA pixels, not v2)

// IMPORTANT: To reduce NeoPixel burnout risk, add 1000 uF capacitor across
// pixel power leads, add 300 - 500 Ohm resistor on first pixel's data input
// and minimize distance between Arduino and first pixel.  Avoid connecting
// on a live circuit...if you must, connect GND first.
 
void setup() 
{
  strip.begin();
  strip.show(); // Initialize all pixels to 'off'
}
 
void loop() {
  // Sequenze monocolore
  colorWipe(strip.Color(rouge, vert, bleu), 0); // white yellow
  delay(20);
  colorWipe(strip.Color(0, 0, 0), 0); // white yellow
  delay(20);
  /* Tremolii
  theaterChase(strip.Color(127, 127, 127), 50); // White
  theaterChase(strip.Color(127, 0, 0), 50); // Red
  theaterChase(strip.Color(0, 0, 127), 50); // Blue
  */

  //rainbow(20);
  //rainbowCycle(20);
  //theaterChaseRainbow(10);
}
 
// Fill the dots one after the other with a color
void colorWipe(uint32_t c, uint8_t wait) {
  for(uint16_t i=0; i<strip.numPixels(); i++) {
    strip.setPixelColor(i, c);
    strip.show();
    delay(wait);
  }
}

void colorWipe2(uint32_t c, uint8_t wait) {
  int n=int(strip.numPixels()/3);
  for(uint16_t i=0; i<n; i++) {
    strip.setPixelColor(i, c);
    strip.setPixelColor(i+n, c);
    strip.setPixelColor(i+2*n, c);
    strip.show();
    delay(wait);
  }
}

void rainbow(uint8_t wait) {
  uint16_t i, j;
 
  for(j=0; j<256; j++) {
    for(i=0; i<strip.numPixels(); i++) {
      strip.setPixelColor(i, Wheel((i+j) & 255));
    }
    strip.show();
    delay(wait);
  }
}
 
// Slightly different, this makes the rainbow equally distributed throughout
void rainbowCycle(uint8_t wait) {
  uint16_t i, j;
 
  for(j=0; j<256*5; j++) { // 5 cycles of all colors on wheel
    for(i=0; i< strip.numPixels(); i++) {
      strip.setPixelColor(i, Wheel(((i*256/strip.numPixels())+j)&255));
    }
    strip.show();
    delay(wait);
  }
}
 
//Theatre-style crawling lights.
void theaterChase(uint32_t c, uint8_t wait) {
  for (int j=0; j<10; j++) {  //do 10 cycles of chasing
    for (int q=0; q < 3; q++) {
      for (int i=0; i < strip.numPixels(); i=i+3) {
        strip.setPixelColor(i+q, c); //turn every third pixel on
      }
      strip.show();
 
      delay(wait);
 
      for (int i=0; i < strip.numPixels(); i=i+3) {
        strip.setPixelColor(i+q, 0); //turn every third pixel off
      }
    }
  }
}
 
//Theatre-style crawling lights with rainbow effect
void theaterChaseRainbow(uint8_t wait) {
  for (int j=0; j < 256; j++) {     // cycle all 256 colors in the wheel
    for (int q=0; q < 3; q++) {
      for (int i=0; i < strip.numPixels(); i=i+3) {
        //turn every third pixel on
        strip.setPixelColor(i+q, Wheel( (i+j) % 255)); 
      }
      strip.show();
 
      delay(wait);
 
      for (int i=0; i < strip.numPixels(); i=i+3) {
        strip.setPixelColor(i+q, 0);        //turn every third pixel off
      }
    }
  }
}
 
// Input a value 0 to 255 to get a color value.
// The colours are a transition r - g - b - back to r.
uint32_t Wheel(byte WheelPos) {
  WheelPos = 255 - WheelPos;
  if(WheelPos < 85) {
    return strip.Color(255 - WheelPos * 3, 0, WheelPos * 3);
  }
  if(WheelPos < 170) {
    WheelPos -= 85;
    return strip.Color(0, WheelPos * 3, 255 - WheelPos * 3);
  }
  WheelPos -= 170;
  return strip.Color(WheelPos * 3, 255 - WheelPos * 3, 0);
}