Max30102 didn't give me the result I expected, does the problem with the code? #4
Description
Hi there,
I'm try max30102 with nodemcu everything is alright, except the readings I get are changing with a huge different it sometimes give a negative No. (-999) when SpO2 isn't valid, there is no other negative No. other than this, but I don't like that. I want it to give readings when its valid and waiting when it's not valid.
this is the code used:
`
// Include section
#include <Wire.h>
#include "MAX30105.h"
#include "spo2_algorithm.h"
#include "heartRate.h"
// Definitions
#define MAX_BRIGHTNESS 255
// Variables declaration
#if defined(__AVR_ATmega328P__) || defined(__AVR_ATmega168__)
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
// Heart rate vars
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;
// sampling times
unsigned long prevHRTime;
unsigned long prevSP02Time;
// Sensor object instantiation
MAX30105 particleSensor;
// Setup
void setup(){
// Initialize serial port and configure your sensor
Serial.begin(115200);
Serial.println("Initializing...");
// Initialize sensor
if (!particleSensor.begin(Wire, I2C_SPEED_FAST))
{
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
prevHRTime = millis();
prevSP02Time = millis();
}
// main loop
void loop(){
unsigned long now = millis();
// if(now - prevHRTime > 50){
// prevHRTime = now;
//
heart_rate(); // Implementation is below
//
// }
}
void heart_rate(){
long irValue = particleSensor.getIR();
if (checkForBeat(irValue) == true)
{
//We sensed a beat!
long delta = millis() - lastBeat;
lastBeat = millis();
beatsPerMinute = 60 / (delta / 1000.0);
Serial.print("true");
// ------------------------------------------------------
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
}
//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(", HR=");
Serial.print(heartRate, DEC);
Serial.print(", SPO2=");
Serial.print(spo2, DEC);
Serial.print(", 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);
}
//--------------------------------------------------------
Serial.print("IR=");
Serial.print(irValue);
Serial.print(", BPM=");
Serial.print(beatsPerMinute);
// Serial.println();
}
if (irValue < 50000)
{
beatsPerMinute = 0;
beatAvg = 0;
Serial.print(" No finger?");
Serial.println();
}
}
,
this is the result I got:
,
No finger?
true, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=88, SPO2=-999, SPO2Valid=0
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=53, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=62, SPO2=14, SPO2Valid=1
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=-999, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=107, SPO2=-999, SPO2Valid=0
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=214, SPO2=63, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=136, SPO2=84, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=72, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=250, SPO2=48, SPO2Valid=1
, HR=214, SPO2=61, SPO2Valid=1
,