SENDER: Arduino Sketch

void setup(){  Serial.begin(9600);}void loop(){    Serial.println(analogRead(0));    delay(10);  }

import processing.serial.*;int lf = 10;    // Linefeed in ASCIIString myString = null;Serial myPort;  // The serial portvoid setup() {   size(200, 200);  // List all the available serial ports  println(Serial.list());  // Open the port you are using at the rate you want:  myPort = new Serial(this, Serial.list()[5], 9600);  myPort.clear();  // Throw out the first reading, in case we started reading   // in the middle of a string from the sender.  myString = myPort.readStringUntil(lf);  myString = null;}void draw() {  int wert;  while (myPort.available() > 0) {    myString = myPort.readStringUntil(lf);    if (myString != null) {     println(myString);      background(255);             // Set background to white                  wert=int(trim(myString));  println(wert); //  fill(wert);                   // set fill to black fill(wert);  rect(50, 50, 100, 100);    }  }}


http://wikis.zum.de/zum/Arduino/Datenvisualisierung_mit_Processing

Using Arduino as Oscilloscope - ArduinoScope!