Sistem Digital Line Follower (Processing Code)

import processing.serial.*;

Serial myPort;  // Create object from Serial class
String val;     // Data received from the serial port

int rectWidth;

void setup()
{
  // I know that the first port in the serial list on my mac
  // is Serial.list()[0].
  // On Windows machines, this generally opens COM1.
  // Open whatever port is the one you're using.
  printArray(Serial.list());
  String portName = Serial.list()[1]; //change the 0 to a 1 or 2 etc. to match your port
  myPort = new Serial(this, "COM10", 9600);
  myPort.bufferUntil('\n');
//  myPort = new Serial(this, portName, 9600);
  size(300,300);
  noStroke();
  background(150);
  rectWidth = width/4;

}

void serialEvent (Serial myPort){ // Checks for available data in the Serial Port
  val = myPort.readStringUntil('\n'); //Reads the data sent from the Arduino (the String "LED: OFF/ON) and it puts into the "ledStatus" variable
}

void draw(){
  textSize(32);
}

void keyPressed(){
  if (key == '8'){ myPort.write('8'); background(150); text("Maju",width/2, 135);}
    if (key == '5'){ myPort.write('5'); background(200); text("Berhenti",width/2, 135);}
    if (key == '6'){ myPort.write('6'); background(230); text("Speed+",width/2, 135);}
    if (key == '4'){ myPort.write('4'); background(100); text("Speed-",width/2, 135);}
    if (key == '2'){ myPort.write('2'); background(80); text("Mundur",width/2, 135);}
}