//PWM on pins 3 and 11 will not work when using this code, because we are using Timer 2!
//The following variables are automatically updated:
//Signal :    int that holds the analog signal data straight from the sensor. updated every 2mS.
//IBI  :      int that holds the time interval between beats. 2mS resolution.
//BPM  :      int that holds the heart rate value, derived every beat, from averaging previous 10 IBI values.
//QS  :       boolean that is made true whenever Pulse is found and BPM is updated. User must reset.
//Pulse :     boolean that is true when a heartbeat is sensed then false in time with pin13 LED going out.

int pulsePin = 0;                 // Pulse Sensor purple wire connected to analog pin 0
int blinkPin = 13;                // pin to blink led at each beat
int fadePin = 5;                  // pin to do fancy classy fading blink at each beat
int fadeRate = 0;                 // used to fade LED on with PWM on fadePin


// these variables are volatile because they are used during the interrupt service routine!
volatile int BPM;                   // used to hold the pulse rate
volatile int Signal;                // holds the incoming raw data
volatile int IBI = 600;             // holds the time between beats, must be seeded!
volatile boolean Pulse = false;     // true when pulse wave is high, false when it's low
volatile boolean QS = false;        // becomes true when Arduoino finds a beat.


void setup(){
  pinMode(blinkPin,OUTPUT);         // pin that will blink to your heartbeat!
  //pinMode(fadePin,OUTPUT);          // pin that will fade to your heartbeat!
  Serial.begin(4800);               // we agree to talk fast!
  interruptSetup();                 // sets up to read Pulse Sensor signal every 2mS
  analogReference(EXTERNAL);        // powering by 3.3V
}



void loop(){
  //sendDataToProcessing('S', Signal);     // send Processing the raw Pulse Sensor data
  if (QS == true){                       // Quantified Self flag is true when arduino finds a heartbeat
    //fadeRate = 255;                  // Set 'fadeRate' Variable to 255 to fade LED with pulse
    //sendDataToProcessing('B',BPM);   // send heart rate with a 'B' prefix
    //sendDataToProcessing('Q',IBI);   // send time between beats with a 'Q' prefix
    sendBPM(BPM);
    QS = false;                      // reset the Quantified Self flag for next time
  }

  //ledFadeToBeat();

  delay(20);                             //  take a break
}

void sendBPM(int BPM){
  Serial.println(BPM);
}