Arduino & Adafruit Capacitive Sensor

/*************************************************** 
  This is a library for the CAP1188 I2C/SPI 8-chan Capacitive Sensor

  Designed specifically to work with the CAP1188 sensor from Adafruit
  ----> https://www.adafruit.com/products/1602

  These sensors use I2C/SPI to communicate, 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 <SPI.h>
#include <Adafruit_CAP1188.h>

// Reset Pin is used for I2C or SPI
#define CAP1188_RESET  9

// CS pin is used for software or hardware SPI
//#define CAP1188_CS  10

// These are defined for software SPI, for hardware SPI, check your 
// board's SPI pins in the Arduino documentation
//#define CAP1188_MOSI  11
//#define CAP1188_MISO  12
//#define CAP1188_CLK  13

#define CAP1188_SENSITIVITY 0x1F

// For I2C, connect SDA to your Arduino's SDA pin, SCL to SCL pin
// On UNO/Duemilanove/etc, SDA == Analog 4, SCL == Analog 5
// On Leonardo/Micro, SDA == Digital 2, SCL == Digital 3
// On Mega/ADK/Due, SDA == Digital 20, SCL == Digital 21

// Use I2C, no reset pin!
Adafruit_CAP1188 cap = Adafruit_CAP1188();

// Or...Use I2C, with reset pin
//Adafruit_CAP1188 cap = Adafruit_CAP1188(CAP1188_RESET);

// Or... Hardware SPI, CS pin & reset pin 
// Adafruit_CAP1188 cap = Adafruit_CAP1188(CAP1188_CS, CAP1188_RESET);

// Or.. Software SPI: clock, miso, mosi, cs, reset
//Adafruit_CAP1188 cap = Adafruit_CAP1188(CAP1188_CLK, CAP1188_MISO, CAP1188_MOSI, CAP1188_CS, CAP1188_RESET);

void setup() {
  Serial.begin(9600);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo/Micro only
  }
  Serial.println("CAP1188 test!");
  
  
  // Initialize the sensor, if using i2c you can pass in the i2c address
  // if (!cap.begin(0x28)) {
  if (!cap.begin()) {
    Serial.println("CAP1188 not found");
    while (1);
  }
  Serial.println("CAP1188 found!");
  //Decrease sensitivity a little - default is 0x2F (32x) per datasheet
  //cap.writeRegister(CAP1188_SENSITIVITY, 0x3F);  // 16x sensitivity
  //cap.writeRegister(CAP1188_SENSITIVITY, 0x4F);  // 8x  sensitivity
  //cap.writeRegister(CAP1188_SENSITIVITY, 0x5F);  // 4x  sensitivity
  cap.writeRegister(CAP1188_SENSITIVITY, 0x6F);  // 2x  sensitivity THIS SEEMS TO WORK THE BEST FOR 3.5" plate sensors
  //cap.writeRegister(CAP1188_SENSITIVITY, 0x7F);  // 1x  sensitivity
  //Serial.print("Sensitivity: 0x");
  //Serial.println(cap.readRegister(CAP1188_SENSITIVITY), HEX);
}

void loop() {
  uint8_t touched = cap.touched();
  if (touched == 0) {
    // No touch detected
    return;
  }
  
  for (uint8_t i=0; i<8; i++) {        // Check each bit, each bit represents 1 sensor
    if (touched & (1 << i)) {
      Serial.print("C"); Serial.print(i+1); Serial.print("\t");
    }
  }
  Serial.println();
  delay(50);
}