Arduino Starter Kit example
Project 13 - Touch Sensor Lamp

This sketch is written to accompany Project 13 in the
Arduino Starter Kit

Parts required:
1 Megohm resistor
metal foil or copper mesh
220 ohm resistor

Software required :
CapacitiveSensor library by Paul Badger

Created 18 September 2012
by Scott Fitzgerald

This example code is part of the public domain

// import the library (must be located in the
// Arduino/libraries directory)
#include <CapacitiveSensor.h>

// create an instance of the library
// pin 4 sends electrical energy
// pin 2 senses senses a change
CapacitiveSensor capSensor = CapacitiveSensor(4, 2);

// threshold for turning the lamp on
int threshold = 1000;

// pin the LED is connected to
const int ledPin = 12;

void setup() {
  // open a serial connection
  // set the LED pin as an output
  pinMode(ledPin, OUTPUT);

void loop() {
  // store the value reported by the sensor in a variable
  long sensorValue = capSensor.capacitiveSensor(30);

  // print out the sensor value

  // if the value is greater than the threshold
  if (sensorValue > threshold) {
    // turn the LED on
    digitalWrite(ledPin, HIGH);
  // if it's lower than the threshold
  else {
    // turn the LED off
    digitalWrite(ledPin, LOW);