Setting up the Blynk Android App:

Published May 28, 2021 © Apache-2.0

DIY heart rate monitor and pulse oximeter

DIY heart rate monitor and pulse oximeter using MAX30100 Pulse Oximeter Heart Rate Sensor Module.

BeginnerFull instructions provided2,735

Things used in this project

Hardware components

NodeMCU ESP8266 Breakout Board

Maxim Integrated MAX30100

Breadboard (generic)

Jumper wires (generic)

Software apps and online services

Arduino IDE

Hand tools and fabrication machines

Soldering iron (generic)

Story

India is badly hit by the second wave of COVID 19. There's a shortage of pulse oximeters. I and my family got infected with COVID 19 and couldn't find any Oximeters for a reasonable price anywhere. So I searched the internet to find any DIY solution and came across this cheap MAX30100 pulse oximeter and heart rate sensor module.

General Description ofMAX30100:-

The MAX30100 is an integrated pulse oximetry and heart rate monitor sensor solution. It combines two LEDs, a photodetector, optimized optics, and low-noise analog signal processing to detect pulse oximetry and heart-rate signals. The MAX30100 operates from 1.8V and 3.3V power supplies and can be powered down through software with negligible standby current, permitting the power supply to remain connected at all times.

System Block Diagram:-

MAX30100 block diagram

*for more information on MAX30100 sensor, please visit - https://datasheets.maximintegrated.com/en/ds/MAX30100.pdf

Setting up the Blynk Android App:-

Blynk is an application that runs over Android and IOS devices to controlany IoT based application using Smartphones. It allows you to createyour Graphical user interface for IoT application. Here we will setup the Blynk application to monitor BPM & SPO2 over Wi-Fi usingNodeMCU ESP8266.

1.So download and install the Blynk Application from Google Play store.IOS users can download from the App Store. Once the installation iscompleted, open the app & sign-up using your Email id and Password.

2. Now click on “New Project”. In the pop up set the parameters like Project name, Board and connection type as shown in the photo above.For this MAX30100 ESP8266 project select the device as NodeMCU and connection type as Wi-Fi. Then click on Create.

3.Now click on the “+” sign to add the widgets. We need to read thevalue of BPM & SpO2. So select a pair of widget named “ValueDisplay” & “Gauge”.

4.After dragging the widgets, set their parameters as shown in theimage above. Click on Value Display and set the pin to “V7” &“V8“. Similarly, in gauge settings, set the output pin to “V7”& “V8”.

Afterthe successful creation of the Project, go back to setting and clickon Send Email. You will get an Authenticate ID on registered mail.Save the Authenticate ID for future reference.

Code

MAX30100 with ESP8266 and BLYNK

#include <Wire.h>
#include "MAX30100_PulseOximeter.h"
#define BLYNK_PRINT Serial
#include <Blynk.h>
#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>
 
#include "Wire.h"

#define REPORTING_PERIOD_MS 1000

// PulseOximeter is the higher level interface to the sensor
// it offers:
//  * beat detection reporting
//  * heart rate calculation
//  * SpO2 (oxidation level) calculation
 
char auth[] = "v60fhfJerBZAZzmYbwS2uSzs2Qvy6sjK";             // You should get Auth Token in the Blynk App.
char ssid[] = "TP-LINK_9950";                                     // Your WiFi credentials.
char pass[] = "8348502146";
 
// Connections : SCL PIN - D1 , SDA PIN - D2 , INT PIN - D0
PulseOximeter pox;
 
float BPM, SpO2;
uint32_t tsLastReport = 0;
 
// Callback (registered below) fired when a pulse is detected
 
void onBeatDetected()
{
    Serial.println("Beat!");
}
 
void setup()
{
    Serial.begin(115200);
    
    pinMode(16, OUTPUT);
    Blynk.begin(auth, ssid, pass);
 
    Serial.print("Initializing Pulse Oximeter..");
    // Initialize the PulseOximeter instance
    // Failures are generally due to an improper I2C wiring, missing power supply
    // or wrong target chip
 
    if (!pox.begin()) {
        Serial.println("FAILED");
        for(;;);
    } else {
        Serial.println("SUCCESS");
    }

    // The default current for the IR LED is 50mA and it could be changed
    //   by uncommenting the following line. Check MAX30100_Registers.h for all the
    //   available options.
    // pox.setIRLedCurrent(MAX30100_LED_CURR_7_6MA);

    // Register a callback for the beat detection
    pox.setOnBeatDetectedCallback(onBeatDetected);
 
}
 
void loop()
{
    pox.update();
    Blynk.run();
 
    BPM = pox.getHeartRate();
    SpO2 = pox.getSpO2();
    
   if (millis() - tsLastReport > REPORTING_PERIOD_MS)
    {
        Serial.print("Heart rate:");
        Serial.print(BPM);
        Serial.print(" bpm / SpO2:");
        Serial.print(SpO2);
        Serial.println(" %");
 
        Blynk.virtualWrite(V7, BPM);
        Blynk.virtualWrite(V8, SpO2);
 
        tsLastReport = millis();
    }
}

Credits

manodeep

0 projects • 4 followers

DIY heart rate monitor and pulse oximeter

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Setting up the Blynk Android App:-

Schematics

MAX30100 with ESP8266

Code

MAX30100 with ESP8266 and BLYNK

Credits

manodeep

Comments

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DIY heart rate monitor and pulse oximeter

DIY heart rate monitor and pulse oximeter

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Setting up the Blynk Android App:-

Schematics

MAX30100 with ESP8266

Code

MAX30100 with ESP8266 and BLYNK

Credits

manodeep

Comments

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