Fading example

gistfile1.txt

#include <Adafruit_NeoPixel.h>

#define PIN            D1
#define TRIGGER        D2

// How many NeoPixels are attached to the Arduino?
#define NUMPIXELS      16

int oldVal = LOW;
int newVal = LOW;

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

int delayval = 500; // delay for half a second

void setup() {
  pinMode(TRIGGER, INPUT);
  pixels.begin(); // This initializes the NeoPixel library.
  delay(100);
  setAll(255, 0, 0);
  delay(200);
}

void loop() {

  newVal = digitalRead(TRIGGER);
  
  if(newVal != oldVal) {
    if(newVal == HIGH) {
      fadeIn(0);
    } else {
     fadeOut(0);
   }
   oldVal = newVal;
  } else {
    if(oldVal == HIGH) {
      setAll(255, 0, 0);
    } else {
      setAll(0, 0, 0);
    }
  }
  
  delay(20);
 }

void setAll(byte red, byte green, byte blue) {
  for(int i = 0; i < NUMPIXELS; i++ ) {
    pixels.setPixelColor(i, red, green, blue);
  }
  pixels.show();  
}

void showStrip() {
   // NeoPixel
   pixels.show();
}

void fadeIn(int color ) {
      for(int k = 0; k < 256; k++) {
      switch(color) {
        case 0: setAll(k,0,0); break;
        case 1: setAll(0,k,0); break;
        case 2: setAll(0,0,k); break;
      }
      showStrip();
      delay(15);
    }
}

void fadeOut(int color) {
      for(int k = 255; k >= 0; k--) {
      switch(color) {
        case 0: setAll(k,0,0); break;
        case 1: setAll(0,k,0); break;
        case 2: setAll(0,0,k); break;
      }
      showStrip();
      delay(15);
    }
}