Hello all, this is my first post to this forum so I will apologize up front for my super-newbie question.  I just bought my first Arduino board and I am trying to get it to listen to an LED that I have flashing on a seperate breadboard.  The breadboard is hooked up to a Basic Stamp microcontroller.  It is a simple circuit that switches a pin on the Basic Stamp from HIGH to LOW every 1.5 seconds.  I took a jumper and wired it from the same row as the positive end of the LED that is flashing and inserted it into pin 13 on the digital side of the Arduino board.  I am using the Processing program for the Arduino below to try and detect when the LED is on and off but am sure I am doing something very wrong.  Any help would be greatly appreciated.

import processing.serial.*;
import cc.arduino.*;

Arduino arduino;
int ledPin = 13;
int val;
void setup()
{
 //size(300,300);
 println(Arduino.list());
 arduino = new Arduino(this, Arduino.list()[3], 57600);
}

void draw()
{
// background(off);
//  stroke(on);
 for (int i = 0; i < 6; i++) {
   if (arduino.digitalRead(ledPin) == Arduino.HIGH){
     fill(153);
     println("grey");
 }    else {
    noFill();
    println("no fill");
 }
  // rect(420 - i * 30, 30, 20, 20);
 }
 
 }