8 channel Capacive Touch Button

/* FILE:    TTP229_16_Key_Capacitive_Touch_Example
   DATE:    25/02/15
   VERSION: 0.1
   
REVISIONS:

25/02/15 Created version 0.1

This example sketch will read the current state of the
of the keypad and if a key is pressed output its key number to the serial port.

The sketch assumes that the keypad is configured to 16 key active low mode
by shorting pads P1-3 and P1-P4 together (see schematic or sport forum for more
information). Connect the keypad to your Arduino as follows:

Keypad......Arduino
VCC.........+5V
GND.........GND
SCL.........Digital pin 8
SDO.........Digital pin 9

/* Define the digital pins used for the clock and data */
#define SCL_PIN 8
#define SDO_PIN 9

/* Used to store the key state */
byte Key;

void setup()
{
  /* Initialise the serial interface */
  Serial.begin(9600);
  /* Configure the clock and data pins */
  pinMode(SCL_PIN, OUTPUT); 
  pinMode(SDO_PIN, INPUT);
}


/* Main program */
void loop()
{
  /* Read the current state of the keypad */
  Key = Read_Keypad();
 
  /* If a key has been pressed output it to the serial port */
  if (Key)
    Serial.println(Key);

  /* Wait a little before reading again
     so not to flood the serial port*/
  delay(100);
}


/* Read the state of the keypad */
byte Read_Keypad(void)
{
  byte Count;
  byte Key_State = 0;

  /* Pulse the clock pin 16 times (one for each key of the keypad)
     and read the state of the data pin on each pulse */
  for(Count = 1; Count <= 16; Count++)
  {
    digitalWrite(SCL_PIN, LOW);
   
    /* If the data pin is low (active low mode) then store the
       current key number */
    if (!digitalRead(SDO_PIN))
      Key_State = Count;
   
    digitalWrite(SCL_PIN, HIGH);
  } 
 
  return Key_State;
}