user10028: I have a question about using the Arduino and Processing. I want to build a touch sensor using aluminum foil and connect it to an interface built in Processing. However i've come across a problem. I don't know how to send the serial data from the Arduino to Processing. This is the code I'm using to get the sensor value from the aluminum foil:
#include <CapacitiveSensor.h>


CapacitiveSensor   cs_4_2 = CapacitiveSensor(4,2);   


void setup(){
  Serial.begin(9600);
}

void loop(){
  long start = millis();
  long total1 =  cs_4_2.capacitiveSensor(30);

  Serial.print(millis() - start);        
  Serial.print("\t");                    

  Serial.print(total1);                  
  Serial.print("\t"); 
  Serial.print('\n');

  delay(100);          
}

The foil is connected to dig pin 4 with a resistor of 1M in between and to dig pin 2 with a resistor of 1K. Pin 4 is the send pin, pin 2 is the receive pin. It all works just fine, in the serial monitor in the Arduino software I get the value of the time between refreshes and the sensor value. But how do I use this sensor value in a Processing sketch? I thought of maybe using Firmata on the Arduino, but then I wouldn't know how to use the CapacitiveSensor library and get the sensor values. Does anyone know how to get this to work? Help would be greatly appreciated!

user8644: Try to use this code:
// Graphing sketch

import processing.serial.*;

Serial myPort;        // The serial port
int xPos = 1;         // horizontal position of the graph

void setup () {
// set the window size:
size(400, 300);        

// List all the available serial ports
println(Serial.list());
// I know that the first port in the serial list on my mac
// is always my  Arduino, so I open Serial.list()[0].
// Open whatever port is the one you're using.
myPort = new Serial(this, Serial.list()[0], 9600);
// don't generate a serialEvent() unless you get a newline character:
myPort.bufferUntil('\n');
// set inital background:
background(0);
}
void draw () {
// everything happens in the serialEvent()
}

void serialEvent (Serial myPort) {
// get the ASCII string:
String inString = myPort.readStringUntil('\n');

if (inString != null) {
// trim off any whitespace:
inString = trim(inString);
// convert to an int and map to the screen height:
float inByte = float(inString);
inByte = map(inByte, 0, 1023, 0, height);

// draw the line:
stroke(127,34,255);
line(xPos, height, xPos, height - inByte);

// at the edge of the screen, go back to the beginning: 
if (xPos >= width) {
xPos = 0;
background(0);
}
else {
// increment the horizontal position:
xPos++;
}
}
}

Also look at: http://www.arduino.cc/en/Tutorial/Graph

10028: <p>I have a question about using the Arduino and Processing. I want to build a touch sensor using aluminum foil and connect it to an interface built in Processing. However i've come across a problem. I don't know how to send the serial data from the Arduino to Processing. This is the code I'm using to get the sensor value from the aluminum foil:</p>

<pre><code>#include &lt;CapacitiveSensor.h&gt;


CapacitiveSensor   cs_4_2 = CapacitiveSensor(4,2);   


void setup(){
  Serial.begin(9600);
}

void loop(){
  long start = millis();
  long total1 =  cs_4_2.capacitiveSensor(30);

  Serial.print(millis() - start);        
  Serial.print("\t");                    

  Serial.print(total1);                  
  Serial.print("\t"); 
  Serial.print('\n');

  delay(100);          
}
</code></pre>

<p>The foil is connected to dig pin 4 with a resistor of 1M in between and to dig pin 2 with a resistor of 1K. Pin 4 is the send pin, pin 2 is the receive pin. It all works just fine, in the serial monitor in the Arduino software I get the value of the time between refreshes and the sensor value. But how do I use this sensor value in a Processing sketch? I thought of maybe using Firmata on the Arduino, but then I wouldn't know how to use the CapacitiveSensor library and get the sensor values. Does anyone know how to get this to work? Help would be greatly appreciated!</p>
 8644: <p>Try to use this code:</p>

<pre><code>// Graphing sketch

import processing.serial.*;

Serial myPort;        // The serial port
int xPos = 1;         // horizontal position of the graph

void setup () {
// set the window size:
size(400, 300);        

// List all the available serial ports
println(Serial.list());
// I know that the first port in the serial list on my mac
// is always my  Arduino, so I open Serial.list()[0].
// Open whatever port is the one you're using.
myPort = new Serial(this, Serial.list()[0], 9600);
// don't generate a serialEvent() unless you get a newline character:
myPort.bufferUntil('\n');
// set inital background:
background(0);
}
void draw () {
// everything happens in the serialEvent()
}

void serialEvent (Serial myPort) {
// get the ASCII string:
String inString = myPort.readStringUntil('\n');

if (inString != null) {
// trim off any whitespace:
inString = trim(inString);
// convert to an int and map to the screen height:
float inByte = float(inString);
inByte = map(inByte, 0, 1023, 0, height);

// draw the line:
stroke(127,34,255);
line(xPos, height, xPos, height - inByte);

// at the edge of the screen, go back to the beginning: 
if (xPos &gt;= width) {
xPos = 0;
background(0);
}
else {
// increment the horizontal position:
xPos++;
}
}
}
</code></pre>

<p>Also look at: <a href="http://www.arduino.cc/en/Tutorial/Graph" rel="nofollow">http://www.arduino.cc/en/Tutorial/Graph</a></p>
