SPO2 sensor code

SPO2sensor.ino

#include "MAX30105.h"
#include "spo2_algorithm.h"

MAX30105 heartAndOxigenSensor;
uint32_t irBuffer[50];  //infrared LED sensor data
uint32_t redBuffer[50]; //red LED sensor data
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
bool isFirstIteration;
String resultHearAndOxigenSensor = "";

long bps = 9600;
int aplicationDelay = 500;


void setup()
{
  isFirstIteration = true;
  bufferLength = 50; //buffer length of 100 stores 4 seconds of samples running at 25sps
  
  if (!heartAndOxigenSensor.begin(Wire, I2C_SPEED_FAST)) //Use default I2C port, 400kHz speed
    {
      while (1)
      {
      }
    }

  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 = 50;    //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

  heartAndOxigenSensor.setup(ledBrightness, sampleAverage, ledMode, sampleRate, pulseWidth, adcRange); 

}

void loop()
{
  HeartAndOxigenSensorControl();

  delay(500);
}

void HeartAndOxigenSensorControl()
{
  if (isFirstIteration)
  {
    isFirstIteration = false;

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

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

    //calculate heart rate and SpO2 after first 50 samples (first 4 seconds of samples)
    maxim_heart_rate_and_oxygen_saturation(irBuffer, bufferLength, redBuffer, &spo2, &validSPO2, &heartRate, &validHeartRate);
  }

  //dumping the first 12 sets of samples in the memory and shift the last 50 sets of samples to the top
  for (byte i = 12; i < bufferLength; i++)
  {
    redBuffer[i - 12] = redBuffer[i];
    irBuffer[i - 12] = irBuffer[i];
  }

  //take 38 sets of samples before calculating the heart rate.
  for (byte i = 38; i < bufferLength; i++)
  {
    while (heartAndOxigenSensor.available() == false) //do we have new data?
    {
      heartAndOxigenSensor.check(); //Check the sensor for new data
    }

    redBuffer[i] = heartAndOxigenSensor.getRed();
    irBuffer[i] = heartAndOxigenSensor.getIR();

    heartAndOxigenSensor.nextSample(); //We're finished with this sample so move to next sample
  }

  //After gathering 25 new samples recalculate HR and SP02
  maxim_heart_rate_and_oxygen_saturation(irBuffer, bufferLength, redBuffer, &spo2, &validSPO2, &heartRate, &validHeartRate);

  if (validSPO2 == 1)
  {
    //Read the values and display them on LCD and leds
    resultHearAndOxigenSensor = "";
    resultHearAndOxigenSensor.concat(spo2);

  }
  else
  {
    //No data readed, show it on LCD
    resultHearAndOxigenSensor = "";
    resultHearAndOxigenSensor.concat("-");
  }
}