gistfile1.ino

#include <CapacitiveSensor.h>

CapacitiveSensor capSensor = CapacitiveSensor(4,2);

const int numReadings = 10;

long readings[numReadings];      // the readings from the analog input
int index = 0;                  // the index of the current reading
long total = 0;                  // the running total
long average = 0;                // the average

boolean isOn = false;

long prevTimeChanged = 0;

void setup()
{
  // initialize serial communication with computer:
  Serial.begin(9600);   
  pinMode(13, OUTPUT);  
  // initialize all the readings to 0: 
  for (int thisReading = 0; thisReading < numReadings; thisReading++)
    readings[thisReading] = 0;          
}

void loop() {
  // subtract the last reading:
  total= total - readings[index];         
  // read from the sensor:  
  readings[index] =  capSensor.capacitiveSensor(300);
  // add the reading to the total:
  total= total + readings[index];       
  // advance to the next position in the array:  
  index = index + 1;                    

  // if we're at the end of the array...
  if (index >= numReadings)              
    // ...wrap around to the beginning: 
    index = 0;                           

  // calculate the average:
  average = total / numReadings;         
  // send it to the computer as ASCII digits
  Serial.println(average);   

  long currentTime = millis();


  if (average > 35.0 && (currentTime - prevTimeChanged > 2000)) {

    prevTimeChanged = currentTime;

    if (isOn) {
      isOn = false;
      digitalWrite(13, LOW);
    } 
    else {
      isOn = true;
      digitalWrite(13, HIGH);
    }

  }


  delay(1);        // delay in between reads for stability            
}