jeffmer / tinypulseppg Goto Github PK

Hello,

First of all I would like to congratulate for the excellent job you did. I developed myself a version of "tinyPulsePPG" with MAX30105 sensor using you project as reference . Thank you.
Now comes my question/concern regarding SpO2 calculation. You present two options for SpO2 calculation: one linear and the other quadratic.
With regards on the linear equation, in the documentation you mention "104 - 1.7 * R", but inside the code you implement "104-0.17 * R+0.5". Fact that is a bit confusing. Anyhow, the implemented linear equation works fine.
If possible, please clarify this concern (or may be I'm wrong).
Other way around, using as reference a guideline from Maxim Integrated (https://www.maximintegrated.com/en/design/technical-documents/app-notes/6/6845.html) , I implemented also a quadratic equation : "1.5958 * R * R - 34.6596 * R + 112.6898 " with very close results to your linear implemented eq. I was afraid of wrong results, the coefficients of quadratic equation being for MAX30101 , me using MAX30105 (as I said). But no problem. It worked well.

Hi @jeffmer ,

Could I use one of the images of the device prototype in my thesis?
If yes, how should I reference you??

Best,
Arritmic

I am using a 128x64 ssd1306. I can write data to oled display's lower half. I would like to have the PulseOxy data display on the first 31 lines and the BME sensor data display on lines 33-63.
I can add 'test' data ie: temp = 98.6 but cannot figure out how to add live data.
I added a function to calculate the variables, but calling the function hangs the program.

void draw_oled(int msg) {
oled.firstPage();

do {
switch (msg) {
case 0: oled.drawStr(10, 0, F("Device error"), 1);
break;
case 1:
oled.drawStr(13, 2, F("PLACE"), 1); //13,10
oled.drawStr(10, 16, F("FINGER"), 1); //10,20
oled.drawChar(100, 0, voltage / 10 + '0');
oled.drawChar(106, 0, '.');
oled.drawChar(112, 0, voltage % 10 + '0');
oled.drawChar(118, 0, 'V');
oled.drawStr(84, 16, F("Display"), 1); //84,14
oled.drawStr(0, 34, F("T: "), 1);
oled.drawChar(26, 34, 'F');
// temp = 1.8 * bme280.readTemperature() + 32;
temp = 98.6;
// Serial.println(temp);
print_digit(12, 34, temp, "F", 2, 1);
oled.drawStr(64, 34, F("H: "), 1);
print_digit(76, 34, humi, "F", 2, 1);
oled.drawChar(94, 34, '%');
oled.drawStr(0, 45, F("Alt: "), 1);

    print_digit(25, 45, alt, "F", 3, 1);
    oled.drawStr(0, 57, F("P: "), 1);
    print_digit(12, 57, pres, "F", 3, 1);
    oled.drawStr(34, 57, F("mmHg"), 1);
    if (draw_Red)
      oled.drawStr(84, 24, F("Red"), 1);
    else
      oled.drawStr(84, 24, F("IR"), 1);
    if (filter_for_graph)
      oled.drawStr(108, 24, F("Avg"), 1);
    else
      oled.drawStr(108, 24, F("Raw"), 1);
    break;

Hello

Downloaded the source code and the first issue I found is that there are 2 filenames with the same name, difference is on capitalized letters and windows doesn't accept it.

After that opening the project will give errors like:

'USISR' was not declared in this scope

Hey Jeff,

This is an interesting project and could you please upload the circuit schematic when using Arduino nano instead of the Attiny85? In the folder nanopulsePPG I can find code right?

Thank you!