Girish Khanna
Published © MIT

WizFi360-EVB-Mini Pulse Oximeter Blynk BPM

I'll build a pulse oximeter using MAX30102 and WizFi360-EVB-Mini that will track the Blood Oxygen level and send the data via Wi-Fi.

BeginnerFull instructions provided2 hours135
WizFi360-EVB-Mini Pulse Oximeter Blynk BPM

Things used in this project

Hardware components

WIZnet WizFi360-EVB-Mini
×1
Raspberry Pi Pico
Raspberry Pi Pico
×1
MAX30102 High-Sensitivity Pulse Oximeter and Heart-Rate Sensor for Wearable Health
Maxim Integrated MAX30102 High-Sensitivity Pulse Oximeter and Heart-Rate Sensor for Wearable Health
×1
Jumper wires (generic)
Jumper wires (generic)
×5

Software apps and online services

Blynk
Blynk
Arduino IDE
Arduino IDE

Story

Read more

Schematics

WizFi360-EVB-Mini

Connections

Final output

Dashboard

Code

WizFi360-EVB-Mini_Pulse_Oximeter_Blynk BPM.ino

Arduino
/*************************************************************
 WizFi360-EVB-Mini Pulse Oximeter Blynk BPM

 By: Girish Khanna 
 
 Date: 08-08-2022
 *************************************************************/
#include <Wire.h>
#include "MAX30105.h"
#include "spo2_algorithm.h"

#include <ESP8266_Lib.h>
#include <BlynkSimpleShieldEsp8266.h>

// Template ID, Device Name and Auth Token are provided by the Blynk.Cloud
// See the Device Info tab, or Template settings
#define BLYNK_TEMPLATE_ID "TEMP"
#define BLYNK_DEVICE_NAME "Device"
#define BLYNK_AUTH_TOKEN "Token"

// Comment this out to disable prints and save space
#define BLYNK_PRINT Serial

MAX30105 particleSensor;

#define MAX_BRIGHTNESS 255

char auth[] = BLYNK_AUTH_TOKEN;

// Your WiFi credentials.
// Set password to "" for open networks.
char ssid[] = "SSID";
char pass[] = "Pass";

// Hardware Serial on Mega, Leonardo, Micro...
#define EspSerial Serial2

// or Software Serial on Uno, Nano...
//#include <SoftwareSerial.h>
//SoftwareSerial EspSerial(2, 3); // RX, TX

// Your ESP8266 baud rate:
#define ESP8266_BAUD 115200

ESP8266 wifi(&EspSerial);

#if defined(__AVR_ATmega328P__) || defined(__AVR_ATmega168__)
//Arduino Uno doesn't have enough SRAM to store 100 samples of IR led data and red led data in 32-bit format
//To solve this problem, 16-bit MSB of the sampled data will be truncated. Samples become 16-bit data.
uint16_t irBuffer[100]; //infrared LED sensor data
uint16_t redBuffer[100];  //red LED sensor data
#else
uint32_t irBuffer[100]; //infrared LED sensor data
uint32_t redBuffer[100];  //red LED sensor data
#endif

int32_t bufferLength; //data length
int32_t spo2; //SPO2 value
int8_t validSPO2; //indicator to show if the SPO2 calculation is valid
int32_t heartRate; //heart rate value
int8_t validHeartRate; //indicator to show if the heart rate calculation is valid

byte pulseLED = 11; //Must be on PWM pin
byte readLED = 13; //Blinks with each data read

BlynkTimer timer;

// This function sends Arduino's uptime every second to Virtual Pin 2.
void myTimerEvent()
{
  // You can send any value at any time.
  // Please don't send more that 10 values per second.
  Blynk.virtualWrite(V1, heartRate); //HR
  Blynk.virtualWrite(V2, millis() / 1000);
  Blynk.virtualWrite(V3, spo2); //SPO2
  Blynk.virtualWrite(V4, validHeartRate); //PRESENSE
  Blynk.virtualWrite(V5, "WiizFi360 HRM"); //TEXT1
}

void setup()
{
  // Debug console
  Serial.begin(115200);

  // Set ESP8266 baud rate
  EspSerial.begin(ESP8266_BAUD);
  delay(10);

  pinMode(pulseLED, OUTPUT);
  pinMode(readLED, OUTPUT);

  // Initialize sensor
  if (!particleSensor.begin(Wire, I2C_SPEED_FAST)) //Use default I2C port, 400kHz speed
  {
    Serial.println(F("MAX30105 was not found. Please check wiring/power."));
    while (1);
  }

  Serial.println(F("Attach sensor to finger with rubber band. Press any key to start conversion"));

  byte ledBrightness = 60; //Options: 0=Off to 255=50mA
  byte sampleAverage = 4; //Options: 1, 2, 4, 8, 16, 32
  byte ledMode = 2; //Options: 1 = Red only, 2 = Red + IR, 3 = Red + IR + Green
  byte sampleRate = 100; //Options: 50, 100, 200, 400, 800, 1000, 1600, 3200
  int pulseWidth = 411; //Options: 69, 118, 215, 411
  int adcRange = 4096; //Options: 2048, 4096, 8192, 16384

  Serial.println("Initializing...");
  particleSensor.setup(ledBrightness, sampleAverage, ledMode, sampleRate, pulseWidth, adcRange); //Configure sensor with these settings
  Blynk.begin(auth, wifi, ssid, pass);

  // Setup a function to be called every second
  timer.setInterval(1000L, myTimerEvent);
}

void loop()
{
  bufferLength = 100; //buffer length of 100 stores 4 seconds of samples running at 25sps

  //read the first 100 samples, and determine the signal range
  for (byte i = 0 ; i < bufferLength ; i++)
  {
    while (particleSensor.available() == false) //do we have new data?
      particleSensor.check(); //Check the sensor for new data

    redBuffer[i] = particleSensor.getRed();
    irBuffer[i] = particleSensor.getIR();
    particleSensor.nextSample(); //We're finished with this sample so move to next sample

    Serial.print(F("red="));
    Serial.print(redBuffer[i], DEC);
    Serial.print(F(", ir="));
    Serial.println(irBuffer[i], DEC);
  }

  //calculate heart rate and SpO2 after first 100 samples (first 4 seconds of samples)
  maxim_heart_rate_and_oxygen_saturation(irBuffer, bufferLength, redBuffer, &spo2, &validSPO2, &heartRate, &validHeartRate);

  //Continuously taking samples from MAX30102.  Heart rate and SpO2 are calculated every 1 second
  while (1)
  {
    //dumping the first 25 sets of samples in the memory and shift the last 75 sets of samples to the top
    for (byte i = 25; i < 100; i++)
    {
      redBuffer[i - 25] = redBuffer[i];
      irBuffer[i - 25] = irBuffer[i];
    }

    //take 25 sets of samples before calculating the heart rate.
    for (byte i = 75; i < 100; i++)
    {
      while (particleSensor.available() == false) //do we have new data?
        particleSensor.check(); //Check the sensor for new data

      digitalWrite(readLED, !digitalRead(readLED)); //Blink onboard LED with every data read

      redBuffer[i] = particleSensor.getRed();
      irBuffer[i] = particleSensor.getIR();
      particleSensor.nextSample(); //We're finished with this sample so move to next sample

      //send samples and calculation result to terminal program through UART
      Serial.print(F("red="));
      Serial.print(redBuffer[i], DEC);
      Serial.print(F(", ir="));
      Serial.print(irBuffer[i], DEC);

      Serial.print(F(", HR="));
      Serial.print(heartRate, DEC);

      Serial.print(F(", HRvalid="));
      Serial.print(validHeartRate, DEC);

      Serial.print(F(", SPO2="));
      Serial.print(spo2, DEC);

      Serial.print(F(", SPO2Valid="));
      Serial.println(validSPO2, DEC);
    }
    //After gathering 25 new samples recalculate HR and SP02
    maxim_heart_rate_and_oxygen_saturation(irBuffer, bufferLength, redBuffer, &spo2, &validSPO2, &heartRate, &validHeartRate);
  }
  
  Blynk.run();
  timer.run();
}

Credits

Girish Khanna

Girish Khanna

2 projects • 2 followers
Game Developer, Hobbyist and a Maker

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