//Definitions
int Q0=12;  //Read pins
int Q1=11;
int Q2=10;
int Q3=9;

int rb0=0;  //Read bits
int rb1=0;
int rb2=0;
int rb3=0;

int CP=13;  //Clock pin is LED pin
int count=0;  

void setup() {                
  Serial.begin(9600);
  pinMode(CP, OUTPUT);
  pinMode(Q0, INPUT);    
  pinMode(Q1, INPUT);
  pinMode(Q2, INPUT);
  pinMode(Q3, INPUT);
}

void loop() {
  rb0=digitalRead(Q0);  //Reads the counters bits
  rb1=digitalRead(Q1); 
  rb2=digitalRead(Q2); 
  rb3=digitalRead(Q3); 

  count=rb0+2*rb1+4*rb2+8*rb3;  //Converts the bits to decimal
  
  Serial.println(count);  //Prints count to serial monitor
  digitalWrite(CP,HIGH);  //Clock pulse advances count by one
  delay(3);  //Just so you can see the LED better.
  digitalWrite(CP,LOW);
  delay(500);  //Slows the Arduino so you can see the counting
}