Mirko Pavleski
Published © GPL3+

MAX 30102 Heart Rate Monitor on 16x2 LCD

Build an Arduino heart rate monitor with a MAX30102 sensor and a 16x2 LCD.

BeginnerFull instructions provided12,251
MAX 30102 Heart Rate Monitor on 16x2 LCD

Things used in this project

Hardware components

Arduino Nano R3
Arduino Nano R3
MAX 30102 Heart rate monitor
RGB Backlight LCD - 16x2
Adafruit RGB Backlight LCD - 16x2
Rotary potentiometer (generic)
Rotary potentiometer (generic)

Software apps and online services

Arduino IDE
Arduino IDE

Hand tools and fabrication machines

Soldering iron (generic)
Soldering iron (generic)


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Untitled file

  Optical Heart Rate Detection (PBA Algorithm) using the MAX30105 Breakout
  By: Bennu @ MH-ET LIVE
  Date: October 2nd, 2017

  This is a demo to show the reading of heart rate or beats per minute (BPM) using
  a Penpheral Beat Amplitude (PBA) algorithm.

  It is best to attach the sensor to your finger using a rubber band or other tightening
  device. Humans are generally bad at applying constant pressure to a thing. When you
  press your finger against the sensor it varies enough to cause the blood in your
  finger to flow differently which causes the sensor readings to go wonky.

  Hardware Connections (Breakoutboard to Arduino):
  -5V = 5V (3.3V is allowed)
  -GND = GND
  -SDA = A4 (or SDA)
  -SCL = A5 (or SCL)
  -INT = Not connected

  The MAX30105 Breakout can handle 5V or 3.3V I2C logic. We recommend powering the board with 5V
  but it will also run at 3.3V.

#include <Wire.h>
#include "MAX30105.h"
#include <LiquidCrystal.h>

#include "heartRate.h"

MAX30105 particleSensor;
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

const byte RATE_SIZE = 4; //Increase this for more averaging. 4 is good.
byte rates[RATE_SIZE]; //Array of heart rates
byte rateSpot = 0;
long lastBeat = 0; //Time at which the last beat occurred

float beatsPerMinute;
int beatAvg;

void setup()
  lcd.begin(16, 2);

  // Initialize sensor
  if (!particleSensor.begin(Wire, I2C_SPEED_FAST)) //Use default I2C port, 400kHz speed
    Serial.println("MAX30105 was not found. Please check wiring/power. ");
    while (1);
  Serial.println("Place your index finger on the sensor with steady pressure.");

  particleSensor.setup(); //Configure sensor with default settings
  particleSensor.setPulseAmplitudeRed(0x0A); //Turn Red LED to low to indicate sensor is running
  particleSensor.setPulseAmplitudeGreen(0); //Turn off Green LED

void loop()
  long irValue = particleSensor.getIR();

  if (checkForBeat(irValue) == true)
    //We sensed a beat!
    long delta = millis() - lastBeat;
    lastBeat = millis();

    beatsPerMinute = 60 / (delta / 1000.0);

    if (beatsPerMinute < 255 && beatsPerMinute > 20)
      rates[rateSpot++] = (byte)beatsPerMinute; //Store this reading in the array
      rateSpot %= RATE_SIZE; //Wrap variable

      //Take average of readings
      beatAvg = 0;
      for (byte x = 0 ; x < RATE_SIZE ; x++)
        beatAvg += rates[x];
      beatAvg /= RATE_SIZE;

  Serial.print(", BPM=");
  Serial.print(", Avg BPM=");

  if (irValue < 50000)
    Serial.print(" No finger?");


  lcd.print("BPM: ");

  lcd.print(" IR: ");


Mirko Pavleski

Mirko Pavleski

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