24/4 Array Scanner

#include <Adafruit_NeoPixel.h>
#include <avr/power.h>
#define PIN 6
#define NUMPIXELS 24
Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);
String input = "";
int firstVal, secondVal;
const int numberOfPieces = 96;
String pieces[numberOfPieces];
int counter = 0;
int lastIndex = 0;

void setup() {
  pixels.begin();
  Serial.begin(250000);
}

void loop() {
  if (Serial.available() > 0) {
    char ch = Serial.read();
    if (ch == '\n') {
      for (int i = 0; i < input.length(); i++) {
        if (input.substring(i, i + 1) == ",") {
          pieces[counter] = input.substring(lastIndex, i);
          lastIndex = i + 1;
          counter++;
        }
        if (i == input.length() - 1) { pieces[counter] = input.substring(lastIndex, i); }
      }
      for(int i = 0;i<96;i += 4)
      {
        pixels.setPixelColor(pieces[i].toInt(), pixels.Color(pieces[i+1].toInt(),pieces[i+2].toInt(),  pieces[i+3].toInt()));
      }
      pixels.show();
      input = "";
      counter = 0;
      lastIndex = 0;
    }
    else {
      input += ch;
    }
  }
}