#include <LiquidCrystal_I2C.h>
#include <SoftwareSerial.h>
#include <OneWire.h>
#include <DallasTemperature.h>
#include <Wire.h>
#include "MAX30100_PulseOximeter.h"
#define REPORTING_PERIOD_MS 1000
PulseOximeter pox;
uint32_t tsLastReport = 0;
float oxy_lvl = 0.00;
unsigned char alert = 0;
unsigned char system_alert = 0;
unsigned char alert_flag=0;
LiquidCrystal_I2C lcd(0x27,16,2);
SoftwareSerial myserial(13, 12); // RX, TX for blood pressure sensor
SoftwareSerial esp8266(19, 18); // rx,tx for esp8266
#define ONE_WIRE_BUS 3
#define HELP_TONE buzz, 2000, 200
const int buzz=9;
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);
float cel=0.00;
String data_pressure;
char buff[15];
String send_data_string;
const int no_of_data = 5;
String main_data[10];
int sensorValue = 0;
unsigned int tempVal = 0;
int sys_u = 130, dia_u = 90, temp_l = 24, temp_u = 37, pulse_l = 30, pulse_u = 120;
int sys, dia, p, stay = 1;
void onBeatDetected()
{
Serial.println("Heart beat detected!! Oximeter pulse detected!!");
}
void setup()
{
pinMode(buzz, OUTPUT);
Serial.begin(9600);
esp8266.begin(9600);
myserial.begin(9600);
sensors.begin();
sensors.setWaitForConversion(false);
lcd.begin();
lcd.clear();
Serial.print("Initializing Oximeter and other sensors");
if(!pox.begin())
{
Serial.println("Oximeter Failed");
lcd.print("Oximeter Failed");
for(;;);
}
else
{
Serial.println("Oximeter Succeeded");
}
pox.setIRLedCurrent(MAX30100_LED_CURR_7_6MA);
pox.setOnBeatDetectedCallback(onBeatDetected);
lcd.print(F(" Patient "));
lcd.setCursor(0, 1);
lcd.print(F(" Health Monitor "));
delay(2000);
send_data_string = String(sys) + ',' + String(dia) + ',' + String(p) + ',' + String(cel) + ',' + String(oxy_lvl);
Serial.println("send_data_string = " + String(send_data_string));
send_parameters();
delay(4000);
lcd.clear();
}
void loop()
{
digitalWrite(buzz,LOW);
read_temperature_and_oxi();
main_display();
myserial.listen();
if (myserial.available())
{
while (myserial.available())
{
data_pressure = myserial.readString();
}
data_pressure.trim();
data_pressure.toCharArray(buff, data_pressure.length() + 1);
if (sscanf(buff, "%d,%d,%d", &sys, &dia, &p) == 3)
{
lcd.clear();
lcd.print(F("sys | dia | puls"));
lcd.setCursor(0, 1);
lcd.print(sys);
lcd.setCursor(7, 1);
lcd.print(dia);
lcd.setCursor(12, 1);
lcd.print(p);
delay(7500);
read_temperature_and_oxi();
process();
alerting();
delay(500);
send_data_string = String(sys) + ',' + String(dia) + ',' + String(p) + ',' + String(cel) + ',' + String(oxy_lvl);
Serial.println("send_data_string = " + String(send_data_string));
send_parameters();
delay(3000);
}
myserial.end();
}
myserial.listen();
delay(1);
}
void read_temperature_and_oxi()
{
float HeartRate = 3.0, SpO2 = 3.0;
if(millis() - tsLastReport > REPORTING_PERIOD_MS)
{
pox.update();
HeartRate = pox.getHeartRate();
SpO2 = pox.getSpO2();
Serial.print("Heart Rate: ");
Serial.print(HeartRate);
Serial.print("bpm / SpO2: ");
Serial.print(SpO2);
Serial.println(" % ");
sensors.requestTemperatures();
cel=sensors.getTempCByIndex(0);
Serial.print("Temperatures: ");
Serial.print(cel);
Serial.println("");
oxy_lvl=SpO2;
tsLastReport=millis();
}
}
void main_display()
{
lcd.clear();
lcd.print(F("Temp: "));
lcd.setCursor(6, 0);
lcd.print(cel);
lcd.print((char)223);
lcd.print('C');
lcd.setCursor(0, 1);
lcd.print("SpO2: ");
lcd.setCursor(6 ,1);
lcd.print(oxy_lvl);
delay(200);
}
void send_parameters()
{
esp8266.listen();
esp8266.flush();
esp8266.print(send_data_string);
delay(5000);
lcd.clear();
lcd.setCursor(0,0);
lcd.print(F(" Uploaded To "));
lcd.setCursor(0,1);
lcd.print(F(" Firebase "));
delay(200);
esp8266.end();
}
void help_display()
{
lcd.clear();
lcd.print(F(" PATIENT NEEDS "));
lcd.setCursor(6, 1);
lcd.print(F("HELP "));
}
void process()
{
if((sys > sys_u) || (dia > dia_u))
{
system_alert = 1;
}
else if((p < pulse_l ) || (p > pulse_u))
{
system_alert = 2;
}
else if((cel < temp_l ) || (cel > temp_u))
{
system_alert = 3;
}
else
{
system_alert = 0;
}
delay(200);
}
void alerting()
{
if(system_alert==1)
{
lcd.clear();
digitalWrite(buzz,HIGH);
lcd.setCursor(0,0);
lcd.print("Patient BP");
lcd.setCursor(0,1);
lcd.print("Fluctuating");
delay(3500);
}
else if(system_alert==2)
{
lcd.clear();
digitalWrite(buzz,HIGH);
lcd.setCursor(0,0);
lcd.print("Patient Pulse");
lcd.setCursor(0,1);
lcd.print("Fluctuating");
delay(3500);
}
else if(system_alert==3)
{
lcd.clear();
digitalWrite(buzz,HIGH);
lcd.setCursor(0,0);
lcd.print("Temperature");
lcd.setCursor(0,1);
lcd.print("Fluctuating");
delay(3500);
}
else
{
Serial.print("Continue Monitoring");
delay(3500);
}
}
Hi. This is for my final year project that I have been tasked with designing a patient monitoring system. However, during the last stretch of model prototyping, I am experiencing issues with my MAX30100 and DS18B20 thermal probe. My thermal probe is giving me a proper reading of the temperature. However, the oximeter values are always stuck to zero and the call back function is not executed. I did read that it was an issue where the thermal probe continues to do conversion and doesn't allow the max30100 sensor to perform any other functions. So for that, i just had to pass sensors.setWaitForConversion(false);
I did try to write the code for the DS18B20 thermal probe and the oximeter sensor seperately and it executed perfectly. However, when I try to integrate everything together into a final project, the max30100 sensor doesn't carry out the reading and is stuck to zero while the thermal probe is perfectly working finding out its temperature. I did the same coding process as the previous when i tried to seperately work with the thermal and oximeter sensor. However, it is the final integration that is causing a lot of issues.
The data will be sent to firebase realtime database via the ESP8266 Wi-Fi module. I have got it to work fine. But i am stuck on the final integration of the BP machine, the MAX30100 Oximeter sensor and the DS18B20 Waterproof Thermal Probe.
Could anyone guide me as to how do I perform integration of the MAX30100 Sensor with the DS18B20 Probe?
Attaching code for the working of the thermal probe and oximeter sensor below. It is a seperate code i wrote for testing purposes.
#include <Wire.h>
#include "MAX30100_PulseOximeter.h"
#include <LiquidCrystal_I2C.h>
#include <OneWire.h>
#include <DallasTemperature.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
PulseOximeter pox;
uint32_t tsLastReport = 0;
LiquidCrystal_I2C lcd(0x27, 16, 2);
#define ONE_WIRE_BUS 5
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);
float cel=0.00;
// Callback (registered below) fired when a pulse is detected
void onBeatDetected()
{
Serial.println("Beat!");
}
void setup()
{
Serial.begin(9600);
Serial.print("Initializing...");
sensors.begin();
sensors.setWaitForConversion(false);
// 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("MAX30100 was not found. Please check the wiring/power.");
lcd.print("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()
{
float HeartRate = 3.0, SpO2 = 3.0;
// Make sure to call update as fast as possible
pox.update();
HeartRate = pox.getHeartRate();
SpO2 = pox.getSpO2();
// Asynchronously dump heart rate and oxidation levels to the serial
// For both, a value of 0 means "invalid"
if (millis() - tsLastReport > REPORTING_PERIOD_MS) {
Serial.print("Heart rate:");
Serial.print(HeartRate);
Serial.print("bpm / SpO2:");
Serial.print(SpO2);
Serial.println("%");
sensors.requestTemperatures();
cel=sensors.getTempCByIndex(0);
Serial.print("Temperature: ");
Serial.print(cel);
Serial.println("");
tsLastReport = millis();
lcd.clear();
lcd.setCursor(0,0);
lcd.print("HR:");
lcd.print(HeartRate);
lcd.print(" bpm");
lcd.setCursor(0,1);
lcd.print("SpO2:");
lcd.print(SpO2);
lcd.print("%");
lcd.setCursor(11,1);
lcd.print("T:");
lcd.print(cel);
}
}
Also, I am using the Arduino Mega 2560 as my Arduino Uno was crashing constantly due to low memory issues.
See 
