Capacitive Sensor No Output

Using Arduino Project Guidance
4

Hi HazardsMind,

Thanks for replying to my post, I tried the code that they suggest at the webpage for the keypad.

/*
TouchWheel.pde
MPR121 WhellPad Example Code

by:Waiman Zhao
Mail:Binpower@foxmail.com
created on: 11/2/14
license: CC-SA 3.0

Hardware: 3.3V Arduino Pro Mini
SDA -> A4
SCL -> A5
IRQ -> D2
*/

#include <Wire.h>
#include <mpr121.h>

int key = 0;

// ========= setup =========
void setup()
{
// initialize function
Serial.begin(19200);
Wire.begin();
CapaTouch.begin();

delay(500);
Serial.println("START");
}

// ========= loop =========
void loop()
{
key=CapaTouch.keyPad();

if (key==11)
{ Serial.print("key:");
Serial.println("*");
}
else if(key==12)
{
Serial.print("key:");
Serial.println("#");
}
else if(key>0){
Serial.print("key:");
Serial.println(key);
}
delay(200);
}

It doesnt have any output at the serial window after I added the library and flashed the Uno. I am a novice in Arduino, I am not sure whether do I need any additional code for it to have an output at the serial window. Please advice