Arduino Random Rainbow Stop

RandomRainbowStop.ino

/*
Arduino Random Rainbow Stop
Random Led Strip Selection
Copyright (c) Davide Gironi, 2015

References:
  + https://github.com/technobly/NeoPixel-KnightRider
  + https://github.com/adafruit/Adafruit_NeoPixel

Released under GPLv3.
Please refer to LICENSE file for licensing information.
*/

#include <Adafruit_NeoPixel.h>
#include <avr/power.h>

// Stop/Start button pin
#define BUTTONPIN 6
// Pin number for the led strip
#define LEDPIN 5
// Number of led connected
#define LEDNUM 12
// Random minimum led increase interval for selection
#define LEDSELMIN 25
// Random minimum led increase interval for selection
#define LEDSELMAX 45
// Minimum time to delay on rainbow random select loop
#define RAINBOWSPEEDMIN 50
// Maximum time to delay on rainbow random select loop
#define RAINBOWSPEEDMAX 80
// With of the previous dim led
#define PREVIOUSLEDDIMWITH 10
// Loop back and forth or circular
#define LOOPBACKANDFORTH 0
// Delay used for rainbow (ms)
#define RAYINBOWDELAYMS 20
// Enabled the idle loop after a button is selected
#define IDLELOOPENABLEDONSELECT 1
// Time to enable the idle loop (ms)
#define IDLELOOPENABLEDTIMEMS 30000

// NeoPixel library initialization
Adafruit_NeoPixel strip = Adafruit_NeoPixel(LEDNUM, LEDPIN, NEO_GRB + NEO_KHZ800);

// Actual led
static uint16_t current_led = 0;

// Actual color number
static uint8_t colornum = 0;

// Actual direction
static uint8_t dir = 1;

// Idle loop
static uint8_t idleloop = 1;

// Setup the Arduino
void setup() {
  uint8_t i;
  
  //set button
  pinMode(BUTTONPIN, INPUT);
  
  //set first led
  current_led = 0;
  //set first color
  colornum = 0;
  
  //initialize random
  randomSeed(analogRead(0));
  
  //start NeoPixel
  strip.begin();
  //set all off
  for(i=0; i< strip.numPixels(); i++) {
    strip.setPixelColor(i, 0, 0, 0);
    strip.show();
  }
  
  //wait a little
  delay(1000);
}

// Main Arduino loop
void loop() {
  uint16_t i, j;
  
  //perform an idleloop
  while(idleloop) {
    for(j=0; j<256; j++) {
      for(i=0; i<strip.numPixels(); i++) {
        strip.setPixelColor(i, colorWheel((i+j) & 255));
      }
      strip.show();
      if(digitalRead(BUTTONPIN) == HIGH) {
        while(digitalRead(BUTTONPIN) == HIGH);
        idleloop = 0;
        //set all off
        for(i=0; i< strip.numPixels(); i++) {
          strip.setPixelColor(i, 0, 0, 0);
          strip.show();
        }
        delay(500);
        break;
      }
      delay(RAYINBOWDELAYMS);
    }
  }
  
  //set the stop led
  uint16_t stop_led = random(LEDSELMIN, LEDSELMAX);
  
  //do the rainbox selection
  stopRainbow(stop_led, RAINBOWSPEEDMIN, RAINBOWSPEEDMAX, PREVIOUSLEDDIMWITH);
  
  //set all off
  for(i=0; i<LEDNUM; i++) {
    strip.setPixelColor(i, 0, 0, 0);
    strip.show();
  }
  
  //stay on the select led until button is pressed, or idle timer is passed
  uint32_t preMillis = millis();
  while(digitalRead(BUTTONPIN) == LOW) {
    #if IDLELOOPENABLEDONSELECT == 1
    uint32_t curMillis = millis();
    if(curMillis - preMillis > IDLELOOPENABLEDTIMEMS) {
      idleloop = 1;
      break;
    }
    #endif
    colornum++;
    uint32_t color = colorWheel(colornum);
    strip.setPixelColor(current_led, color);
    strip.show();
    delay(RAYINBOWDELAYMS);
  }
  //wait for the button to release
  while(digitalRead(BUTTONPIN) == HIGH);

}

// Loop colors and stop on selected led
// stop_led - led to stop on
// speedmin - timed led on/off minimum speed
// speedmax - timed led on/off maxmimum speed
// width - preious leds dim width
void stopRainbow(uint16_t stop_led, uint16_t speedmin, uint16_t speedmax, uint8_t width) {
  uint16_t prev_color[LEDNUM];
  uint16_t current_stopled = 0;
  uint32_t color = 0;
  uint16_t x = 0;
  uint8_t changeddir = 0;
  
  //rest previous color
  for(x=0; x<LEDNUM; x++) {
    prev_color[x] = 0;
  }
      
  while(1) {
    //set a color   
    color = colorWheel(colornum);
    prev_color[current_led] = color;
    strip.setPixelColor(current_led, color);
    
    //dim previous colors
    for(x=0; x<LEDNUM; x++) {
      if(x != current_led) {
        prev_color[x] = dimColor(prev_color[x], width);
        strip.setPixelColor(x, prev_color[x]); 
      }
    }
    
    //show strip
    strip.show();
        
    //next color
    colornum++;
    
    //stop on destination led
    current_stopled++;
    if(current_stopled>stop_led) {
      //stop running
      break;
    }
    
    //next led
    #if LOOPBACKANDFORTH == 1
    if(dir) {
      current_led++;
      if(current_led == LEDNUM-1) {
        dir = 0;
      }
    } else {     
      if(current_led == 0) {
        current_led++;
        dir = 1;
      } else
        current_led--;
    }
    #else
    current_led++;
    if(current_led == LEDNUM)
      current_led = 0;
    #endif
    
    //delay a little
    uint16_t speed = random(speedmin, speedmax);
    delay(speed);
  }
}

// Dim a color given a width
uint32_t dimColor(uint32_t color, uint8_t width) {
   return (((color&0xFF0000)/width)&0xFF0000) + (((color&0x00FF00)/width)&0x00FF00) + (((color&0x0000FF)/width)&0x0000FF);
}

// Input a value 0 to 255 to get a color value.
// The colours are a transition r - g - b - back to r.
uint32_t colorWheel(uint8_t pos) {
  if(pos < 85) {
    return strip.Color(pos * 3, 255 - pos * 3, 0);
  } else if(pos < 170) {
    pos -= 85;
    return strip.Color(255 - pos * 3, 0, pos * 3);
  } else {
    pos -= 170;
    return strip.Color(0, pos * 3, 255 - pos * 3);
  }
}