Language of Love

Heartbeat.ino

// Creation and computation Expriment 4
// Rana Zandi
// November 2016

#include <Ticker.h>
#include "config.h"

Ticker flipper;
Ticker sender;

AdafruitIO_Feed *bpm = io.feed("TK2");

const int maxAvgSample = 20;
volatile int rate[maxAvgSample];                    // used to hold last ten IBI values
boolean sendok = false;
volatile unsigned long sampleCounter = 0;          // used to determine pulse timing
volatile unsigned long lastBeatTime = 0;           // used to find the inter beat interval
volatile int P = 250;                     // used to find peak in pulse wave
volatile int T = 250;                     // used to find trough in pulse wave
volatile int thresh = 250;                // used to find instant moment of heart beat
volatile int amp = 100;                   // used to hold amplitude of pulse waveform
volatile boolean firstBeat = true;        // used to seed rate array so we startup with reasonable BPM
volatile boolean secondBeat = true;       // used to seed rate array so we startup with reasonable BPM
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, the Inter-Beat Interval
volatile boolean Pulse = false;     // true when pulse wave is high, false when it's low
volatile boolean QS = false;

int bpmSample = 3;
int bpmCurrent = 0;
int bpmAverage = 0;
void setup() {
  Serial.begin(115200);
  delay(10);

  Serial.print("Connecting to Adafruit IO");
  // connect to io.adafruit.com
  io.connect();

  // wait for a connection
  while (io.status() < AIO_CONNECTED) {
    Serial.print(".");
    delay(500);
  }

  // we are connected
  Serial.println();
  Serial.println(io.statusText());

  flipper.attach_ms(2, Test);
  sender.attach(2, senderfunc);
}

void senderfunc()
{
  sendok = true;
}



void loop() {
  io.run();

  if (sendok)
  {
    delay(100);
    Serial.println(BPM);
    bpmAverage += BPM;
    if( bpmCurrent == bpmSample){  
      Serial.print("Sending Average :");
      Serial.println(bpmAverage/3);
      bpm->save(bpmAverage/3);
      bpmAverage = 0;
      bpmCurrent = 0;
    }
    bpmCurrent++;
    delay(10);
    sendok = false;
    flipper.attach_ms(2, Test);
  }

}

void sendBMP()
{


}


int count = 0;
void Test()
{
  count++;
  if (count == 1000)
  {
    flipper.detach();
    count = 0;
    sendBMP();
    sendok = true;

  }

  Signal = analogRead(A0);              // read the Pulse Sensor
  sampleCounter += 2;                         // keep track of the time in mS with this variable
  int N = sampleCounter - lastBeatTime;       // monitor the time since the last beat to avoid noise

  if (Signal < thresh && N > (IBI / 5) * 3) { // avoid dichrotic noise by waiting 3/5 of last IBI
    if (Signal < T) {                       // T is the trough
      T = Signal;                         // keep track of lowest point in pulse wave
    }
  }

  if (Signal > thresh && Signal > P) {        // thresh condition helps avoid noise
    P = Signal;                             // P is the peak
  }                                        // keep track of highest point in pulse wave

  //  NOW IT'S TIME TO LOOK FOR THE HEART BEAT
  // signal surges up in value every time there is a pulse
  if (N > 250) {                                  // avoid high frequency noise
    if ( (Signal > thresh) && (Pulse == false) && (N > (IBI / 5) * 3) ) {
      Pulse = true;                               // set the Pulse flag when we think there is a pulse
      //digitalWrite(blinkPin,HIGH);                // turn on pin 13 LED
      IBI = sampleCounter - lastBeatTime;         // measure time between beats in mS
      lastBeatTime = sampleCounter;               // keep track of time for next pulse

      if (firstBeat) {                       // if it's the first time we found a beat, if firstBeat == TRUE
        firstBeat = false;                 // clear firstBeat flag
        return;                            // IBI value is unreliable so discard it
      }
      if (secondBeat) {                      // if this is the second beat, if secondBeat == TRUE
        secondBeat = false;                 // clear secondBeat flag
        for (int i = 0; i <= maxAvgSample - 1; i++) { // seed the running total to get a realisitic BPM at startup
          rate[i] = IBI;
        }
      }

      // keep a running total of the last 10 IBI values
      word runningTotal = 0;                   // clear the runningTotal variable

      for (int i = 0; i <= (maxAvgSample - 2); i++) {        // shift data in the rate array
        rate[i] = rate[i + 1];            // and drop the oldest IBI value
        runningTotal += rate[i];          // add up the 9 oldest IBI values
      }

      rate[maxAvgSample - 1] = IBI;                        // add the latest IBI to the rate array
      runningTotal += rate[maxAvgSample - 1];              // add the latest IBI to runningTotal
      runningTotal /= maxAvgSample;                     // average the last 10 IBI values
      BPM = 60000 / runningTotal;             // how many beats can fit into a minute? that's BPM!
      QS = true;                              // set Quantified Self flag
      // QS FLAG IS NOT CLEARED INSIDE THIS ISR
    }
  }

  if (Signal < thresh && Pulse == true) {    // when the values are going down, the beat is over
    //digitalWrite(blinkPin,LOW);            // turn off pin 13 LED
    Pulse = false;                         // reset the Pulse flag so we can do it again
    amp = P - T;                           // get amplitude of the pulse wave
    thresh = amp / 2 + T;                  // set thresh at 50% of the amplitude
    P = thresh;                            // reset these for next time
    T = thresh;
  }

  if (N > 2500) {                            // if 2.5 seconds go by without a beat
    thresh = 250;                          // set thresh default
    P = 250;                               // set P default
    T = 250;                               // set T default
    lastBeatTime = sampleCounter;          // bring the lastBeatTime up to date
    firstBeat = true;                      // set these to avoid noise
    secondBeat = true;                     // when we get the heartbeat back
  }

  //sei();                                     // enable interrupts when youre done!
}// end isr