2014 New Years Hat

new_years_hat.ino

/*
Date: December 2013
Author: Adam Petrone
New Year's Hat
*/


#include <Adafruit_NeoPixel.h>
const uint8_t NUM_PIXELS = 16;
const uint8_t PIXEL_DATA_PIN = 3;
const uint8_t NUM_COLORS = 6;



const uint8_t LOW_THRESHOLD = 600;
const uint8_t HIGH_THRESHOLD = 830;
const uint8_t FSR_PIN = 4;

const long COLOR_CHANGE_DELAY = 1000;
uint8_t max_led = 0;

const uint8_t NUM_BRIGHTNESS_LEVELS = 6;
uint8_t brightness[] = {
  0, 16, 32, 64, 127, 255
};

Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUM_PIXELS, PIXEL_DATA_PIN);

long next_tick = 0;
long next_color = millis() + COLOR_CHANGE_DELAY;
uint8_t value_below_threshold = 1;

long brightness_countdown = 300;
long current_brightness_level = 0;

uint8_t current_color = 0;

void setup()
{
  pixels.begin();
  pixels.setBrightness( brightness[ current_brightness_level ] );
  
  pinMode(FSR_PIN, INPUT);  
}

// Input a value 0 to 255 to get a color value.
// The colours are a transition r - g - b - back to r.
// (This code is lifted from one of Adafruit's examples)
uint32_t Wheel(Adafruit_NeoPixel & pixels, byte WheelPos) {
  if(WheelPos < 85) {
   return pixels.Color(WheelPos * 3, 255 - WheelPos * 3, 0);
  } else if(WheelPos < 170) {
   WheelPos -= 85;
   return pixels.Color(255 - WheelPos * 3, 0, WheelPos * 3);
  } else {
   WheelPos -= 170;
   return pixels.Color(0, WheelPos * 3, 255 - WheelPos * 3);
  }
}

void wheel()
{
  long current_tick = millis();
  if (current_brightness_level > 0)
  {

    if (current_tick >= next_color)
    {
      next_color = current_tick+COLOR_CHANGE_DELAY;

      max_led++;
      if (max_led >= pixels.numPixels())
      {
        max_led = 0;
            current_color += 32;
            if (current_color > 255)
            {
              current_color = 0;
            }
      }
    }
  }

  uint8_t last_color = current_color-32;
  if (current_color == 0)
  {
    last_color = 223;
  }
  for(int8_t p = 0; p < pixels.numPixels(); ++p)
  {
    if (p > max_led)
    {
      pixels.setPixelColor(pixels.numPixels()-p-1, Wheel(pixels, last_color));
    }
    else if (p == max_led)
    {
      pixels.setPixelColor(pixels.numPixels()-p-1, pixels.Color(255, 255, 255));
    }
    else
    {
      pixels.setPixelColor(pixels.numPixels()-p-1, Wheel(pixels, current_color));      
    }
  }
  pixels.show();

}

void loop()
{

  wheel();
  
  long current_tick = millis();
  
  int value = analogRead(FSR_PIN);
  if (value >= HIGH_THRESHOLD)
  {
      if (value_below_threshold)
      {
        if (current_tick >= next_tick)
        {
          // step down the brightness
          next_tick = current_tick + brightness_countdown;
          value_below_threshold = 0;
          current_brightness_level++;
          // wrap
          if (current_brightness_level > (NUM_BRIGHTNESS_LEVELS-1))
          {
            current_brightness_level = 0;
          }
          
          if (current_brightness_level == 0)
          {
            current_color = 0;
            max_led = 0;
            next_color = current_tick+COLOR_CHANGE_DELAY;
          }
          pixels.setBrightness(brightness[current_brightness_level]);
          

          
          pixels.show();
        }
      }
  }
  else if (value <= LOW_THRESHOLD)
  {
    value_below_threshold = 1;
  }
}