/*

This example will show you how to use the KY-039 heart bear sensor.

Its a simple basic heart beat monitor with a LCD1602A. In this example i did not use a I2C for those who dont have it.

*/

double alpha=0.75;

int period=20;

double refresh=0.0;

void setup(void)

{

Serial.begin(9600);

pinMode(A0,INPUT);

}

void loop(void)

{

static double oldValue=0;

static double oldrefresh=0;

int beat=analogRead(A0);

double value=alpha*oldValue+(0-alpha)*beat;

refresh=value-oldValue;

Serial.print(" Heart Monitor ");

Serial.print(" ");

Serial.println(beat/10);

oldValue=value;

oldrefresh=refresh;

delay(period*10);

}