#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
 #include <avr/power.h> // Required for 16 MHz Adafruit Trinket
#endif

#define PIN 3
#define NUMPIXELS 16 


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

#define DELAYVAL 10



void setup() {

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

 

pixels.begin();

pixels.setBrightness(10);
 
 Serial.begin(9600);
}

void loop() 
{
  pixels.clear();
  int val = analogRead(A0);
  val = map(val, 0, 1023, 0, 18);

 
  if(val == 1)
  {
    for(int i=0; i<1; i++)
    {
      pixels.setPixelColor(i, pixels.Color(0, 225, 0));
      delay(10);
    }
  }

 if(val == 2)
  {
    for(int i=0; i<2; i++)
    {
      pixels.setPixelColor(i, pixels.Color(32, 225, 0));
      delay(10);
    }
  }

  if(val == 3)
  {
    for(int i=0; i<3; i++)
    {
      pixels.setPixelColor(i, pixels.Color(64, 225, 0));
      delay(10);
    }
  }

  if(val == 4)
  {
    for(int i=0; i<4; i++)
    {
      pixels.setPixelColor(i, pixels.Color(96, 225, 0));
      delay(10);
    }
  }

  if(val == 5)
  {
    for(int i=0; i<5; i++)
    {
      pixels.setPixelColor(i, pixels.Color(128, 225, 0));
      delay(10);
    }
  }

  if(val == 6)
  {
    for(int i=0; i<6; i++)
    {
      pixels.setPixelColor(i, pixels.Color(160, 225, 0));
      delay(10);
    }
  }

  if(val == 7)
  {
    for(int i=0; i<7; i++)
    {
      pixels.setPixelColor(i, pixels.Color(192, 225, 0));
      delay(10);
    }
  }

  if(val == 8)
  {
    for(int i=0; i<8; i++)
    {
      pixels.setPixelColor(i, pixels.Color(225, 225, 0));
      delay(10);
    }
  }

  if(val == 9)
  {
    for(int i=0; i<9; i++)
    {
      pixels.setPixelColor(i, pixels.Color(225, 225, 0));
      delay(10);
    }
  }

  if(val == 10)
  {
    for(int i=0; i<10; i++)
    {
      pixels.setPixelColor(i, pixels.Color(225, 192, 0));
      delay(10);
    }
  }

  if(val == 11)
  {
    for(int i=0; i<11; i++)
    {
      pixels.setPixelColor(i, pixels.Color(225, 160, 0));
      delay(10);
    }
  }

  if(val == 12)
  {
    for(int i=0; i<12; i++)
    {
      pixels.setPixelColor(i, pixels.Color(225, 128, 0));
      delay(10);
    }
  }

  if(val == 13)
  {
    for(int i=0; i<13; i++)
    {
      pixels.setPixelColor(i, pixels.Color(225, 96, 0));
      delay(10);
    }
  }

  if(val == 14)
  {
    for(int i=0; i<14; i++)
    {
      pixels.setPixelColor(i, pixels.Color(225, 64, 0));
      delay(10);
    }
  }

  if(val == 15)
  {
    for(int i=0; i<15; i++)
    {
      pixels.setPixelColor(i, pixels.Color(225, 32, 0));
      delay(10);
    }
  }

  if(val == 16)
  {
    for(int i=0; i<16; i++)
    {
      pixels.setPixelColor(i, pixels.Color(225, 0, 0));
      delay(10);
    }
  }

  if(val == 17)
  {
    for(int i=0; i<17; i++)
    {
      pixels.setPixelColor(i, pixels.Color(225, 0, 0));
      delay(10);
    }
  }

  if(val == 18)
  {
    for(int i=0; i<18; i++)
    {
      pixels.setPixelColor(i, pixels.Color(225, 0, 0));
      delay(10);
    }
  }
 
  pixels.show(); 
  
  delay(DELAYVAL);   
}