#include <Adafruit_NeoPixel.h>
#define PIN 7
#define NUMPIXELS 8

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

#define DELAYVAL 30
void setup() {
  pixels.begin();
  Serial.begin(9600);
  Serial.println("Fjöldi notenda:");
}

void loop() {
  char buffer[8];
  char displayBuffer[8];
  int charsRead;
  int val;
  int offset = 0;
  if (Serial.available() > 0)
  {
    for(int i = 0; i < sizeof(buffer); i++){
      displayBuffer[i] = '0';
    }
    charsRead = Serial.readBytesUntil('\n', buffer, sizeof(buffer) - 1);
    buffer[charsRead] = '\0';
    val = atoi(buffer);
    offset = (int)(ceil(log(val) / log(2)));
    itoa(val, buffer, 2);
    Serial.println(buffer);

    for(int i = 0; i < sizeof(buffer); i++){
      displayBuffer[i+(8-offset)] = buffer[i];
    }
    pixels.clear();
  }

  for(int i=0; i < sizeof(buffer); i++) {

    //pixels.setPixelColor(i, pixels.Color(5, 5, 0));
    if (displayBuffer[i] == '1'){
      pixels.setPixelColor(i, pixels.Color(0, 10, 0));
    } else {
      pixels.setPixelColor(i, pixels.Color(10, 0, 0));
    }

  }
  pixels.show();
}