//CODE FOR IR DISTANCE SENSOR + NEOPIXEL ( NO FLICKERING EFFECT)

#include "neopixel.h"
#include <math.h>
// IMPORTANT: Set pixel COUNT, PIN and TYPE
#define PIXEL_PIN D2
#define PIXEL_COUNT 24
#define PIXEL_TYPE WS2812

Adafruit_NeoPixel strip = Adafruit_NeoPixel(PIXEL_COUNT, PIXEL_PIN, PIXEL_TYPE);

int irPin = A0;
int irProximity = 0;
int transitionTime = 5000; // Tranition Time in ms

const int sampleWindow = 50;

int distance = 0; // initialize distance variable
int unsigned long start;
int unsigned long timeElapsed;

void setup() {
  Serial.println( 9600 ); //enable serial monitor
  strip.begin();
  strip.show(); // Initialize all pixels to 'off'
  pinMode( PIXEL_PIN, OUTPUT );
  pinMode(ledPin, OUTPUT);
  start = millis();
  timeElapsed = 0;
}

void loop() {
  distance = sampleProximity();
  Serial.println( distance );

  if(distance > 300){
   for(int i=0; i<strip.numPixels(); i++) {
     strip.setPixelColor(i, 0,0,0);
     strip.show();
   RGB.color(0,0,0);
 }
  if(distance <= 300){
    for(int i=0; i<strip.numPixels(); i++) {
         strip.setPixelColor(i, 255,173,0);
         strip.show();
        RGB.color(255,173,0);
  }
}



int sampleProximity( )
{
  unsigned long startMillis = millis(); // Start of sample window
  int farthest_sample = 0;
  int closest_sample = 1000;
  // collect data for 50 mS
  while (millis() - startMillis < sampleWindow)
  {
    int sample = analogRead( irPin );
    // invert the range, and convert it to a percent
    sample = map( sample, 0, 4095, 1000, 0 );
    // now see if the sample is the lowest;
    if ( sample > farthest_sample ){
    farthest_sample = sample ;
    }
    if ( sample < closest_sample ){
    closest_sample = sample;
    }
  }
  Serial.print( "Farthest = " );
  Serial.println( farthest_sample );
  Serial.print( "Closest = " );
  Serial.println( closest_sample );
  int proximityAverage = (farthest_sample + closest_sample)/2 ;
  return proximityAverage;
}
/*
    METHODS
*/

/**
 * Scale a value returned from a trig function to a byte value.
 * [-1, +1] -> [0, 254]
 * Note that we ignore the possible value of 255, for efficiency,
 * and because nobody will be able to differentiate between the
 * brightness levels of 254 and 255.
 */
byte trigScale(float val) {
  val += 1.0; // move range to [0.0, 2.0]
  val *= 127.0; // move range to [0.0, 254.0]
  return int(val) & 255;
}
/**
 * Map an integer so that [0, striplength] -> [0, 2PI]
 */
float map2PI(int i) {
  return M_PI*2.0*float(i) / float(strip.numPixels());
}
// Input a value 0 to 255 to get a color value.
// The colours are a transition r - g - b - back to r.
uint32_t Wheel(byte WheelPos) {
  if(WheelPos < 85) {
   return strip.Color(WheelPos * 3, 255 - WheelPos * 3, 0);
  } else if(WheelPos < 170) {
   WheelPos -= 85;
   return strip.Color(255 - WheelPos * 3, 0, WheelPos * 3);
  } else {
   WheelPos -= 170;
   return strip.Color(0, WheelPos * 3, 255 - WheelPos * 3);
  }
}
void colorWipe(uint32_t c, int wait) {
  for(uint16_t i=0; i<strip.numPixels(); i++) {
    strip.setPixelColor(i, c);
    strip.show();
    delay(wait);
  }
}