arduino.ino

//===============================
//    arduino
//===============================

void setup(){
  Serial.begin(9600);
  pinMode(13,INPUT);
}

void loop(){
  int val=digitalRead(13);
  Serial.write(val);
}

processing.pde

//===============================
// processing
//===============================
 
import processing.serial.*;
Serial port;

void setup(){
  size(200,200);
  port = new Serial(this,"COM3",9600);
}

void draw(){
  delay(100);
  println(receive);
}

int receive;
 
void serialEvent(Serial p){
  delay(100);
  receive = p.read();
}