#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
 #include <avr/power.h> // Required for 16 MHz Adafruit Trinket
#endif
#define PIN        4
#define NUMPIXELS 60

Adafruit_NeoPixel pixels(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);

byte started = 0;
int startpin = 2;
byte mode;

// mode 1 color
int rone = 255;
int gone = 80;
int bone = 0;

// mode 2 color
int rtwo = 25;
int gtwo = 255;
int btwo = 50;

// =====================================================================================

void setup() {
#if defined(__AVR_ATtiny85__) && (F_CPU == 16000000)
  clock_prescale_set(clock_div_1);
#endif

  pixels.begin(); // INITIALIZE NeoPixel
  pixels.setBrightness(255);
  pinMode(0, OUTPUT);
  pinMode(startpin, INPUT_PULLUP);

  // set first pixel white - mode set listener
  pixels.setPixelColor(0,24,24,24);    pixels.setPixelColor(1,24,24,24);    pixels.show();

  delay(3000);

  // button held on power up = mode 1, if not mode 0; then indicate with first pixel
  if(digitalRead(startpin) == LOW) { mode = 2; } else { mode = 1; }
  if(mode == 1) { pixels.setPixelColor(0,5,0,0);    pixels.setPixelColor(1,0,0,0);    pixels.show(); }  //mode 1 = red
  if(mode == 2) { pixels.setPixelColor(0,0,5,0);    pixels.setPixelColor(1,0,0,0);    pixels.show(); }  //mode 2 = green

  delay(2000);
}

// =====================================================================================


void loop() {
  // empty loop: no output until button pushed
   while(started == 0) {
      if(digitalRead(startpin) == LOW) { started = 1; }
      delay(20);
    }

// red    --------------------------------------------------------------------------------------------
    if(mode == 1) {
     pixels.setBrightness(1); // start at 1, set all pixels to mode 1 color
     for(int j=0; j<NUMPIXELS; j++) {  pixels.setPixelColor(j,rone,gone,bone);  }
     pixels.show();

     // fade in/out on button press
     for(int i=1; i<255; i++) { pixels.setBrightness(i); pixels.show(); delay(10); }
     while(digitalRead(startpin) == HIGH) { delay(80); }
     for(int i=255; i>0; i--) { pixels.setBrightness(i); pixels.show(); delay(10); }
     while(digitalRead(startpin) == HIGH) { delay(80); }

     } // mode 1

// green ----------------------------------------------------------------------------------------
    if(mode == 2) {
     pixels.setBrightness(1); // start at 1, set all pixels to mode 1 color
     for(int j=0; j<NUMPIXELS; j++) {  pixels.setPixelColor(j,rtwo,gtwo,btwo);  }
     pixels.show();

     // fade in/out on button press
     for(int i=1; i<255; i++) { pixels.setBrightness(i); pixels.show(); delay(10); }
     while(digitalRead(startpin) == HIGH) { delay(80); }
     for(int i=255; i>0; i--) { pixels.setBrightness(i); pixels.show(); delay(10); }
     while(digitalRead(startpin) == HIGH) { delay(80); }

     } // mode 2

} // main