above is the wiring diagram, and this is precisely how I have the circuit hooked up. below is the code.
/* Icon made by Pixel perfect from www.flaticon.com */
#include <Adafruit_SSD1331.h>
#include <Arduino_GFX_Library.h>
Arduino_DataBus *bus = new Arduino_HWSPI(3 /* DC */, -1 /* CS */);
Arduino_ST7789 *gfx = new Arduino_ST7789(bus, 2 /* RST */, 3 /* rotation */, true /* IPS */, 135 /* width */, 240 /* height */, 53 /* col offset 1 */, 40 /* row offset 1 */, 52 /* col offset 2 */, 40 /* row offset 2 */);
#include <Wire.h>
#include "algorithm_by_RF.h"
#include "max30102.h"
// uncomment below line if cannot calculate readings
//#define REVERSE_LED
// Icon
#include "heartrate.h"
#include "oxygen.h"
// Interrupt pin
const byte oxiInt = 0; // pin connected to MAX30102 INT
uint32_t elapsedTime, timeStart;
uint32_t aun_ir, aun_red;
uint32_t aun_ir_buffer[BUFFER_SIZE]; //infrared LED sensor data
uint32_t aun_red_buffer[BUFFER_SIZE]; //red LED sensor data
float old_n_spo2; // Previous SPO2 value
uint8_t uch_dummy;
void setup()
{
pinMode(oxiInt, INPUT); //pin D10 connects to the interrupt output pin of the MAX30102
Wire.begin();
Serial.begin(115200);
gfx->begin();
gfx->fillScreen(BLACK);
gfx->draw16bitRGBBitmap(0, 7, (uint16_t*)heartrate.pixel_data, heartrate.width, heartrate.height);
gfx->draw16bitRGBBitmap(0, 71, (uint16_t*)oxygen.pixel_data, oxygen.width, oxygen.height);
Serial.println("Initializing");
gfx->setTextColor(WHITE, BLACK);
gfx->setTextSize(2 /* x scale */, 2 /* y scale */);
gfx->setCursor(72, 0);
gfx->print("Initializing");
maxim_max30102_reset(); //resets the MAX30102
delay(1000);
maxim_max30102_read_reg(REG_INTR_STATUS_1, &uch_dummy); //Reads/clears the interrupt status register
maxim_max30102_init(); //initialize the MAX30102
old_n_spo2 = 0.0;
Serial.println(F("Time[s]\tSpO2\tHR\tRatio\tCorr"));
timeStart = millis();
}
void loop()
{
float n_spo2, ratio, correl; //SPO2 value
int8_t ch_spo2_valid; //indicator to show if the SPO2 calculation is valid
int32_t n_heartrate; //heart rate value
int8_t ch_hr_valid; //indicator to show if the heart rate calculation is valid
int32_t i;
//buffer length of BUFFER_SIZE stores ST seconds of samples running at FS sps
//read BUFFER_SIZE samples, and determine the signal range
for (i = 0; i < BUFFER_SIZE; i++)
{
while (digitalRead(oxiInt) == 1); //wait until the interrupt pin asserts
#ifdef REVERSE_LED
maxim_max30102_read_fifo(&aun_ir, &aun_red); //read from MAX30102 FIFO
#else
maxim_max30102_read_fifo(&aun_red, &aun_ir); //read from MAX30102 FIFO
#endif
if (aun_ir < 5000)
{
break;
}
if (i == 0)
{
gfx->setTextColor(WHITE, BLACK);
gfx->setTextSize(2 /* x scale */, 2 /* y scale */);
gfx->setCursor(72, 0);
gfx->print("Measuring... ");
}
*(aun_ir_buffer + i) = aun_ir;
*(aun_red_buffer + i) = aun_red;
}
if (aun_ir < 5000)
{
gfx->setTextColor(WHITE, BLACK);
gfx->setTextSize(2 /* x scale */, 2 /* y scale */);
gfx->setCursor(72, 0);
gfx->print("Put On Finger");
Serial.print("NO PILOT DETECTED\n");
}
else
{
//calculate heart rate and SpO2 after BUFFER_SIZE samples (ST seconds of samples) using Robert's method
rf_heart_rate_and_oxygen_saturation(aun_ir_buffer, BUFFER_SIZE, aun_red_buffer, &n_spo2, &ch_spo2_valid, &n_heartrate, &ch_hr_valid, &ratio, &correl);
elapsedTime = millis() - timeStart;
elapsedTime /= 1000; // Time in seconds
if (ch_hr_valid && ch_spo2_valid) {
Serial.print(elapsedTime);
Serial.print("\t");
Serial.print(n_spo2);
Serial.print("\t");
Serial.print(n_heartrate, DEC);
Serial.print("\t");
Serial.print(ratio);
Serial.print("\t");
Serial.print(correl);
Serial.println("");
gfx->setTextSize(7 /* x scale */, 7 /* y scale */, 2 /* pixel_margin */);
gfx->setTextColor(GREEN, BLACK);
gfx->setCursor(72, 20);
gfx->print(n_heartrate);
gfx->setTextColor(ORANGE, BLACK);
gfx->setCursor(72, 84);
gfx->print(n_spo2);
old_n_spo2 = n_spo2;
}
}
}
To give some additional context, this setup does work. I can grab readings that are pretty accurate. I can take my finger off and on and I get the correct outputs from that.
I have placed the sensor on other parts of my body like my wrist or my neck and I am still getting accurate readings.
Additionally, from the code, I am ignoring everything sent to the display. I am not using the display, I am simply printing to the serial monitor. That is how I am getting my readings.
The primary concern is that the sensor readings simply max out at 125 BPM
