Hi everyone!
First at all, I shall apologize for my bad English, but it isn´t my mother tongue. 
I purchased a 12 key capacitive touch sensor based on I2C some days ago, and tried connecting it to my Arduino One. So I realized that I am not able to make it working right.
I looked for lots of info, but I am still lost, and that´s something I don´t like. 
I wired the breakout such as it is shown in the pic you can see clicking on here: http://www.naylampmechatronics.com/modules//smartblog/images/30-single-default.jpg
Besides, I was following the next tutorial: Arduino | Adafruit MPR121 12-Key Capacitive Touch Sensor Breakout Tutorial | Adafruit Learning System
I just loaded to my Arduino microcontroller an example to check up that everything was going well. I attached it below.
/*********************************************************
This is a library for the MPR121 12-channel Capacitive touch sensor
Designed specifically to work with the MPR121 Breakout in the Adafruit shop
----> https://www.adafruit.com/products/
These sensors use I2C communicate, at least 2 pins are required
to interface
Adafruit invests time and resources providing this open source code,
please support Adafruit and open-source hardware by purchasing
products from Adafruit!
Written by Limor Fried/Ladyada for Adafruit Industries.
BSD license, all text above must be included in any redistribution
**********************************************************/
#include <Wire.h>
#include "Adafruit_MPR121.h"
// You can have up to 4 on one i2c bus but one is enough for testing!
Adafruit_MPR121 cap = Adafruit_MPR121();
// Keeps track of the last pins touched
// so we know when buttons are 'released'
uint16_t lasttouched = 0;
uint16_t currtouched = 0;
void setup() {
while (!Serial); // needed to keep leonardo/micro from starting too fast!
Serial.begin(9600);
Serial.println("Adafruit MPR121 Capacitive Touch sensor test");
// Default address is 0x5A, if tied to 3.3V its 0x5B
// If tied to SDA its 0x5C and if SCL then 0x5D
if (!cap.begin(0x5A)) {
Serial.println("MPR121 not found, check wiring?");
while (1);
}
Serial.println("MPR121 found!");
}
void loop() {
// Get the currently touched pads
currtouched = cap.touched();
for (uint8_t i=0; i<12; i++) {
// it if *is* touched and *wasnt* touched before, alert!
if ((currtouched & _BV(i)) && !(lasttouched & _BV(i)) ) {
Serial.print(i); Serial.println(" touched");
}
// if it *was* touched and now *isnt*, alert!
if (!(currtouched & _BV(i)) && (lasttouched & _BV(i)) ) {
Serial.print(i); Serial.println(" released");
}
}
// reset our state
lasttouched = currtouched;
// comment out this line for detailed data from the sensor!
return;
// debugging info, what
Serial.print("\t\t\t\t\t\t\t\t\t\t\t\t\t 0x"); Serial.println(cap.touched(), HEX);
Serial.print("Filt: ");
for (uint8_t i=0; i<12; i++) {
Serial.print(cap.filteredData(i)); Serial.print("\t");
}
Serial.println();
Serial.print("Base: ");
for (uint8_t i=0; i<12; i++) {
Serial.print(cap.baselineData(i)); Serial.print("\t");
}
Serial.println();
// put a delay so it isn't overwhelming
delay(100);
}
My problem lies in the fact that what appears in the Serial Monitor is the text "Adafruit MPR121 Capacitive Touch sensor test", and... Nothing else happens! It is kinda disgusting! >:(
So... What could I do? Any sort of help is welcomed! 
Thanks in advance!
I edit coz' I discovered the error. My MPR121 doesn´t work, when I touch one key, the IRQ pin had to change from 5 volts to 0 volts, but it keeps in 5 volts. So, it´s broken down.
The lesson I learnt is: don´t buy at Aliexpress! Especially when it is cheap!
