import processing.serial.*;
  
  String buff = “”;
  int val = 0;
  int NEWLINE = 10;
  Serial port;
  void setup(){
    port = new Serial(this, Serial.list()[0], 9600); // Use the first available port
  }
  void draw(){
    while (port.available() > 0)
      serialEvent(port.read()); //look for data
    background(val); //change background clr based on input data
  }
  void serialEvent(int serial) {
    if(serial != NEWLINE) {
      buff += char(serial); //add on bytes until a newline is found
    } 
    else {
      buff = buff.substring(0, buff.length()-1);
      val = Integer.parseInt(buff)/4; // Parse the String to int
      println(val);
      buff = “”; // Clear the value of “buff”
    }
  }