Finger Heartbeat Detection Sensor Module (KY-039) [S033]

Finger Heartbeat Detection Sensor Module (KY-039) [S033]

https://www.youtube.com/watch?v=PlpGS6BdtK4

*GitHub : https://github.com/rdiot/rdiot-s033.git

* Specs

KY-039 Finger Detector Heartbeat Detection Sensor Module For Arduino

Specification:

Working voltage: 5V

Use IR LED and optical transistor to detect pulsation in fingers

Used for synthesized teaching experiment

Dimensions: 25 x 22 x 17mm

Weight: 2g

* Contents 

- Connect

S ----- A0

Middle ----- 5V

- ----- GND

- Schematic

- Key Code

#include <Wire.h> 

#include <LiquidCrystal_I2C.h>

#define HBDEBUG(i)

 

LiquidCrystal_I2C lcd(0x27,20,4);  // LCD2004

 

int sensorPin = A0;

double alpha = 0.75;

int period = 100;

double change = 0.0;

double minval = 0.0;

const int delayMsec = 60; // 100msec per sample

void setup()

{

  lcd.init();  // initialize the lcd 

  lcd.backlight();

  lcd.print("start LCD2004");

  Serial.begin(9600);

  delay(1000);

 

  lcd.clear();

}

 

void loop()

{

 

  lcd.setCursor(0,0);

  lcd.print("S033:KY-039");

 

 

  static double oldValue = 0;

  static double oldChange = 0;

  int rawValue = analogRead (sensorPin);

  double value = alpha * oldValue + (1 - alpha) * rawValue;

 

  lcd.setCursor(0,1);

  lcd.print("rawValue=" + (String)rawValue + "   ");

 

  oldValue = value;

 

 

  static int beatMsec = 0;

  int heartRateBPM = 0;

  

  if (heartbeatDetected(sensorPin, delayMsec)) {

    heartRateBPM = 60000 / beatMsec;

    //digitalWrite(ledPin,1);

 

    // Print msec/beat and instantaneous heart rate in BPM

    //Serial.print(beatMsec);

    

    lcd.setCursor(0,2);

    lcd.print("beatMsec=" + (String)beatMsec + "    ");

 

 

    lcd.setCursor(0,3); 

     lcd.print("BPM=" + (String)heartRateBPM + "    ");

 

    beatMsec = 0;

  } else {

    //digitalWrite(ledPin,0);

  }

  delay(delayMsec);

  beatMsec += delayMsec;

 

 

  //delay (period);

}

 

bool heartbeatDetected(int IRSensorPin, int delay)

{

  static int maxValue = 0;

  static bool isPeak = false;

  int rawValue;

  bool result = false;

    

  rawValue = analogRead(IRSensorPin);

  // Separated because analogRead() may not return an int

  rawValue *= (1000/delay);

  HBDEBUG(Serial.print(isPeak); Serial.print("p, "));

  HBDEBUG(Serial.print(rawValue); Serial.print("r, "));

  HBDEBUG(Serial.print(maxValue); Serial.print("m, "));

 

  // If sensor shifts, then max is out of whack.

  // Just reset max to a new baseline.

  if (rawValue * 4L < maxValue) {

    maxValue = rawValue * 0.8;

    HBDEBUG(Serial.print("RESET, "));

  }

  

  // Detect new peak

  if (rawValue > maxValue - (1000/delay)) {

    if (rawValue > maxValue) {

      maxValue = rawValue;

    }

    // Only return true once per peak.

    if (isPeak == false) {

      result = true;

      Serial.print(result); Serial.print(",  *");

    }

    isPeak = true;

  } else if (rawValue < maxValue - (3000/delay)) {

    isPeak = false;

    maxValue-=(1000/delay);

 }

  HBDEBUG(Serial.print("\n"));

  return result;

}