Measure Heart Rate and SpO2 with MAX30102

1/* This code works with MAX30102 + 128x32 OLED i2c + Buzzer and Arduino  UNO
2 * It's displays the Average BPM on the screen, with an animation and a buzzer  sound
3 * everytime a heart pulse is detected
4 * It's a modified version of  the HeartRate library example
5 * Refer to www.surtrtech.com for more details  or SurtrTech YouTube channel
6 */
7
8#include <Adafruit_GFX.h>        //OLED  libraries
9#include <Adafruit_SSD1306.h>
10#include <Wire.h>
11#include "MAX30105.h"           //MAX3010x library
12#include "heartRate.h"          //Heart rate  calculating algorithm
13
14MAX30105 particleSensor;
15
16const byte RATE_SIZE  = 4; //Increase this for more averaging. 4 is good.
17byte rates[RATE_SIZE]; //Array  of heart rates
18byte rateSpot = 0;
19long lastBeat = 0; //Time at which the last  beat occurred
20float beatsPerMinute;
21int beatAvg;
22
23#define SCREEN_WIDTH  128 // OLED display width, in pixels
24#define SCREEN_HEIGHT 32 // OLED display  height, in pixels
25#define OLED_RESET    -1 // Reset pin # (or -1 if sharing Arduino  reset pin)
26
27Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);  //Declaring the display name (display)
28
29static const unsigned char PROGMEM  logo2_bmp[] =
30{ 0x03, 0xC0, 0xF0, 0x06, 0x71, 0x8C, 0x0C, 0x1B, 0x06, 0x18, 0x0E,  0x02, 0x10, 0x0C, 0x03, 0x10,              //Logo2 and Logo3 are two bmp pictures  that display on the OLED if called
310x04, 0x01, 0x10, 0x04, 0x01, 0x10, 0x40,  0x01, 0x10, 0x40, 0x01, 0x10, 0xC0, 0x03, 0x08, 0x88,
320x02, 0x08, 0xB8, 0x04,  0xFF, 0x37, 0x08, 0x01, 0x30, 0x18, 0x01, 0x90, 0x30, 0x00, 0xC0, 0x60,
330x00,  0x60, 0xC0, 0x00, 0x31, 0x80, 0x00, 0x1B, 0x00, 0x00, 0x0E, 0x00, 0x00, 0x04, 0x00,  };
34
35static const unsigned char PROGMEM logo3_bmp[] =
36{ 0x01, 0xF0, 0x0F,  0x80, 0x06, 0x1C, 0x38, 0x60, 0x18, 0x06, 0x60, 0x18, 0x10, 0x01, 0x80, 0x08,
370x20,  0x01, 0x80, 0x04, 0x40, 0x00, 0x00, 0x02, 0x40, 0x00, 0x00, 0x02, 0xC0, 0x00, 0x08,  0x03,
380x80, 0x00, 0x08, 0x01, 0x80, 0x00, 0x18, 0x01, 0x80, 0x00, 0x1C, 0x01,  0x80, 0x00, 0x14, 0x00,
390x80, 0x00, 0x14, 0x00, 0x80, 0x00, 0x14, 0x00, 0x40,  0x10, 0x12, 0x00, 0x40, 0x10, 0x12, 0x00,
400x7E, 0x1F, 0x23, 0xFE, 0x03, 0x31,  0xA0, 0x04, 0x01, 0xA0, 0xA0, 0x0C, 0x00, 0xA0, 0xA0, 0x08,
410x00, 0x60, 0xE0,  0x10, 0x00, 0x20, 0x60, 0x20, 0x06, 0x00, 0x40, 0x60, 0x03, 0x00, 0x40, 0xC0,
420x01,  0x80, 0x01, 0x80, 0x00, 0xC0, 0x03, 0x00, 0x00, 0x60, 0x06, 0x00, 0x00, 0x30, 0x0C,  0x00,
430x00, 0x08, 0x10, 0x00, 0x00, 0x06, 0x60, 0x00, 0x00, 0x03, 0xC0, 0x00,  0x00, 0x01, 0x80, 0x00  };
44
45
46void setup() {  
47  display.begin(SSD1306_SWITCHCAPVCC,  0x3C); //Start the OLED display
48  display.display();
49  delay(3000);
50  //  Initialize sensor
51  particleSensor.begin(Wire, I2C_SPEED_FAST); //Use default  I2C port, 400kHz speed
52  particleSensor.setup(); //Configure sensor with default  settings
53  particleSensor.setPulseAmplitudeRed(0x0A); //Turn Red LED to low to  indicate sensor is running
54
55}
56
57void loop() {
58 long irValue = particleSensor.getIR();    //Reading the IR value it will permit us to know if there's a finger on the  sensor or not
59                                           //Also detecting a heartbeat
60if(irValue  > 7000){                                           //If a finger is detected
61    display.clearDisplay();                                   //Clear the display
62    display.drawBitmap(5, 5, logo2_bmp, 24, 21, WHITE);       //Draw the first bmp  picture (little heart)
63    display.setTextSize(2);                                   //Near  it display the average BPM you can display the BPM if you want
64    display.setTextColor(WHITE);  
65    display.setCursor(50,0);                
66    display.println("BPM");             
67    display.setCursor(50,18);                
68    display.println(beatAvg);  
69    display.display();
70    
71  if (checkForBeat(irValue) == true)                        //If  a heart beat is detected
72  {
73    display.clearDisplay();                                //Clear  the display
74    display.drawBitmap(0, 0, logo3_bmp, 32, 32, WHITE);    //Draw  the second picture (bigger heart)
75    display.setTextSize(2);                                //And  still displays the average BPM
76    display.setTextColor(WHITE);             
77    display.setCursor(50,0);                
78    display.println("BPM");             
79    display.setCursor(50,18);                
80    display.println(beatAvg); 
81    display.display();
82    tone(3,1000);                                        //And  tone the buzzer for a 100ms you can reduce it it will be better
83    delay(100);
84    noTone(3);                                          //Deactivate the buzzer  to have the effect of a "bip"
85    //We sensed a beat!
86    long delta = millis()  - lastBeat;                   //Measure duration between two beats
87    lastBeat  = millis();
88
89    beatsPerMinute = 60 / (delta / 1000.0);           //Calculating  the BPM
90
91    if (beatsPerMinute < 255 && beatsPerMinute > 20)               //To  calculate the average we strore some values (4) then do some math to calculate the  average
92    {
93      rates[rateSpot++] = (byte)beatsPerMinute; //Store this  reading in the array
94      rateSpot %= RATE_SIZE; //Wrap variable
95
96      //Take  average of readings
97      beatAvg = 0;
98      for (byte x = 0 ; x < RATE_SIZE  ; x++)
99        beatAvg += rates[x];
100      beatAvg /= RATE_SIZE;
101    }
102  }
103
104}
105  if (irValue < 7000){       //If no finger is detected it inform  the user and put the average BPM to 0 or it will be stored for the next measure
106     beatAvg=0;
107     display.clearDisplay();
108     display.setTextSize(1);                    
109     display.setTextColor(WHITE);             
110     display.setCursor(30,5);                
111     display.println("Please Place "); 
112     display.setCursor(30,15);
113     display.println("your finger ");  
114     display.display();
115     noTone(3);
116     }
117
118}
119