Code from Arduino Demultiplexer and Potentiometer video http://youtu.be/tRjOoweOEaU

arduino_demux_pot.cpp

int sensorPin = A0;
int delayAmt = 0;
int led = 13;    //just a led

void setup(){
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(led, OUTPUT);
  digitalWrite(led, HIGH);
  Serial.begin(9600);
}

void loop () {
  delayAmt = analogRead(sensorPin);
  digitalWrite(2, 0);
  digitalWrite(3, 1);
  digitalWrite(4, 1);
  delay(delayAmt);
  delayAmt = analogRead(sensorPin);
  digitalWrite(2, 0);
  digitalWrite(3, 0);
  digitalWrite(4, 0);
  delay(delayAmt);
  delayAmt = analogRead(sensorPin);
  digitalWrite(2, 0);
  digitalWrite(3, 0);
  digitalWrite(4, 1);
  delay(delayAmt);
  delayAmt = analogRead(sensorPin);
  digitalWrite(2, 0);
  digitalWrite(3, 1);
  digitalWrite(4, 0);
  delay(delayAmt);
  delayAmt = analogRead(sensorPin);
  digitalWrite(2, 1);
  digitalWrite(3, 0);
  digitalWrite(4, 1);
  delay(delayAmt);
  delayAmt = analogRead(sensorPin);
  digitalWrite(2, 1);
  digitalWrite(3, 1);
  digitalWrite(4, 1);
  delay(delayAmt);
  delayAmt = analogRead(sensorPin);
  digitalWrite(2, 1);
  digitalWrite(3, 1);
  digitalWrite(4, 0);
  delay(delayAmt);
  delayAmt = analogRead(sensorPin);
  digitalWrite(2, 1);
  digitalWrite(3, 0);
  digitalWrite(4, 0);
  delay(delayAmt);
  delayAmt = analogRead(sensorPin);
}