#include <Adafruit_NeoPixel.h> // https://github.com/adafruit/Adafruit_NeoPixel
// https://adafruit.github.io/Adafruit_NeoPixel/html/class_adafruit___neo_pixel.html

// #define PIN 0     // ATtiny88
#define PIN 6  // nano
#define PIX 3  // number of WS2812
Adafruit_NeoPixel pixel(PIX, PIN, NEO_GRB + NEO_KHZ800);

#define EYE2 2  // right eye is on Pix 2
#define EYE1 1  // left eye on Pix 1
#define HAL0 0  // HAL0 on Pix 0

unsigned long timerEYE1, timeoutEYE1, timerHAL0, timeoutHAL0 = 25;
int val, dir = 1; 
bool timeoutEYE1Created;

void setup() {
  randomSeed(analogRead(A0));
  pixel.begin();  // INITIALIZE NeoPixel pixel object
  pixel.clear();
  pixel.show();
  pixel.setPixelColor(EYE1, pixel.Color(0, 255, 0));
  pixel.setPixelColor(EYE2, pixel.Color(0, 255, 0));
  pixel.show();
}

void loop() {
  eyePulse();
}

void eyePulse() {
  int pulsetime = 100;
  
  if (!timeoutEYE1Created) { // create one random timeout
    timeoutEYE1Created = 1;
    timeoutEYE1 = random(3000, 10000);
  }
  
  if (millis() - timerHAL0 > timeoutHAL0) {
    timerHAL0 = millis();
    val += dir;
    if (val > 254 || val < 1)
      dir = -dir;
    pixel.setPixelColor(HAL0, pixel.Color(val, val, val));
    pixel.show();
  }

  if (millis() - timerEYE1 > timeoutEYE1) {
    timeoutEYE1Created = 0;
    timerEYE1 = millis();
    pixel.setPixelColor(EYE2, pixel.Color(255, 0, 0));
    pixel.show();
    delay(pulsetime);
    pixel.setPixelColor(EYE2, pixel.Color(0, 255, 0));
    pixel.show();
    delay(pulsetime);
    pixel.setPixelColor(EYE2, pixel.Color(255, 0, 0));
    pixel.show();
    delay(pulsetime);
    pixel.setPixelColor(EYE2, pixel.Color(0, 255, 0));
  }
}