/*
 * Starting and stopping NeoPixels with an IR proximity sensor.
 * Adapted from: https://learn.adafruit.com/neopixel-painter/test-neopixel-strip
 * 
  
*/

#include <Adafruit_NeoPixel.h>

#define PIN 6
#define N_LEDS 33

const int IRPin2 = 16; // no. of LED pin
const long TIMEINTERVAL = 5000; // the time it takes for the LEDs to light up
const int DIODETHRESHOLD = 982; // the strenght of the IR LEDs
long timerstart;

Adafruit_NeoPixel strip = Adafruit_NeoPixel(N_LEDS, PIN, NEO_GRB + NEO_KHZ800);

void setup() {
  timerstart=0;
  pinMode(IRPin2, INPUT);
  strip.begin();
  strip.show();            // Turn OFF all pixels 
  strip.setBrightness(50); // Set BRIGHTNESS to about 1/5 (max = 255)
}

void loop() {
  if (millis()-timerstart>TIMEINTERVAL){
    blink();
    }
   //stop blinking if I detect something in the IR
   int photodiode = analogRead(IRPin2);
   if(photodiode<DIODETHRESHOLD){
    timerstart = millis();
    turnoff();
    }

}
void turnoff() {
  strip.show();
  }
void blink() {
  chase(strip.Color(255, 0, 0)); // Red
  chase(strip.Color(0, 255, 0)); // Green
  chase(strip.Color(0, 0, 255)); // Blue
  }

static void chase(uint32_t c) {
  for(uint16_t i=0; i<strip.numPixels()+4; i++) {
      strip.setPixelColor(i  , c); // Draw new pixel
      strip.setPixelColor(i-4, 0); // Erase pixel a few steps back
      strip.show();
      delay(25);
  }
}