Hallo Bernd,
ich habe noch mal nachgeschlagen: http://arduino.cc/en/Reference/analogRead

Example

int analogPin = 3; // potentiometer wiper (middle terminal) connected to analog pin 3 outside leads to ground and +5V
int val = 0; // variable to store the value read

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

void loop()
{
val = analogRead(analogPin); // read the input pin
Serial.println(val); // debug value
}

... das sollte demnach passen.