#include <Adafruit_NeoPixel.h>
#define PIX_PIN 12
#define PIX_QTY 8
#define COLORS  15
Adafruit_NeoPixel strip(PIX_QTY, PIX_PIN, NEO_GRB + NEO_KHZ800);
int i, c;

void setup() {
  strip.begin(); // start neopix object
  strip.setBrightness(0); // avoid current overload
  strip.clear(); // clear neopix buffer
  strip.setBrightness(255); // set pixel brightness
}

void loop() {
  // walkingpixel();
  // glitter();
  blinker();
}

void blinker() {
  int p = random(8);
  int r = random(256);
  int g = random(256);
  int b = random(256);
  strip.setPixelColor(p, r * random(2), g * random(2), b * random(3));
  strip.show();
  strip.clear();
  delay(100);
}

void glitter() {
  for (byte i = 0; i < PIX_QTY; i++) {
    int p = random(8);
    int r = random(256);
    int g = random(256);
    int b = random(256);
    strip.setPixelColor(p, strip.Color(r * random(2), g * random(2), b * random(2)));
  }
  strip.show();
  delay(100);
}

void walkingpixel() {
  int r, g, b;
  delay(125); // delay 1/8 second between pixels

  if (i == PIX_QTY) {
    i = 0; // reset pixel
    // delay(500); // delay between colors
    c++; // increment color
    if (c == COLORS) { // count colors
      c = 0; // reset color
    }
    strip.clear(); // clear pixel
  }

  switch (c % COLORS) {
    case 0: r = 255; break;
    case 1: r = 255; g = 127; break;
    case 2: r = 255; g = 255; break;
    case 3: r = 255; g = 255; b = 127; break;
    case 4: r = 127; g = 255; break;
    case 5: g = 255; break;
    case 6: g = 255; b = 127; break;
    case 7: g = 255; b = 255; break;
    case 8: g = 255; b = 255; r = 127; break;
    case 9: g = 127; b = 255; break;
    case 10: b = 255; break;
    case 11: b = 255; r = 127; break;
    case 12: b = 255; r = 255; break;
    case 13: b = 255; r = 255; g = 127; break;
    case 14: b = 127; r = 255; break;
    default: break;
  }

  strip.setPixelColor(i, strip.Color(r, g, b)); // climbing pixel
  strip.show();
  strip.setPixelColor(i, strip.Color(0, 0, 0)); // walking pixel - remove for climbing

  i++; // increment pixel
  r = 0; g = 0; b = 0; // reset colors
}