how to compute heart rate and SPO2 from MAX30100

Question

Hello, everybody. I work with Pulse Oximeter and Heart-Rate Sensor MAX30100 from Maxim Intergarted. I get raw data from sensor, but don't find an algorithm, how to compute heart rate and SPO2 level. Can anybody help me? I will be grateful for C code.

koudelad · Answer

Hello, I know this is a year old discussion, but I got to this topic even after searching for MAX30100 example on Google I also own a Heart Rate clickboard and I found this article about a setup of MAX30100 with a lot of useful information. It even links to a great general article about pulse oximetry . Looks like quite a challenge. Unfortunately, Maxim provides only a datasheet and no application note etc. BTW MAX30100 is not recommended for new designs and superseded by MAX30101 and MAX30102.

aswinvenu · Answer

Hi Eswar,

There are couple of libraries available online for MAX30102. Most of them are for arduino or mbed platforms. But with some effort you can re-write it for Atmega16A. Please take a look.

https://os.mbed.com/users/Filea/code/MAX30102/file/02f411fefe6f/max30102.cpp/

https://platformio.org/lib/show/4010/MAX30102

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2ahUKEwiyr4nWuYLoAhX5wzgGHd9JCtoQFjAA…

Here is my suggestion. MAX30102 is drivers are not very complicated. You can write one if you read the Datasheet very carefully. Since you are a beginner I would suggest you to do it by your self. Please follow the steps.

1) Download the data sheets for both target Microcontroller and Sensor.

https://datasheets.maximintegrated.com/en/ds/MAX30102.pdf

http://ww1.microchip.com/downloads/en/devicedoc/atmel-8154-8-bit-avr-atmega16a_datasheet.pdf

2) Read and understand how I2C functions. Understand the registers used in the Microcontrollers for handling I2C

3) Write a function to configure I2C in the Microcontroller

4) Write two sets of functions to read and write a byte through I2C. (twi_read(), twi_write())

5) Now understand the state diagram of MAX30102 operation.

6) Use read and write function to configure the registers in the MAX30102

Rest of the things are very well explained in the MAX30102 datasheet.

Happy Coding.

Regards,

Aswin

aswinvenu · Answer

Hi,

Please check this TI app note for calculating SpO2. The same approach is applicable to maxim chip.

http://www.ti.com/lit/an/slaa655/slaa655.pdf

in brief SpO2 can be calculated

R = (AC RMS of Red / DC of Red)/ (AC RMS of IR / DC of IR)

SpO2 is a percentage value. Using the R value you can calculate the %SpO2

% SpO2= 110 – 25 × R

AC RMS is the RMS value of voltage difference between peak and trough of the RED/IR waveform.

DC is the voltage difference between ground and the trough waveform.

Please ping me in case if you want any more help.

Regards,

Aswin

clem57 · Answer

eswar123 Have you seen https://www.hackster.io/SurtrTech/measure-heart-rate-and-spo2-with-max30102-c2b4d8 ? All the code is there!

aswinvenu · Answer

Please go through these tutorials. They are really good and easy to follow.

https://www.newbiehack.com/MicrocontrollerIntroductionABeginnersGuidetotheAtmelAVRAtmega32.aspx

I2C tutorials can be found here.

https://www.newbiehack.com/I2C-TWI-FirstExample.aspx

Take your time and understand it thoroughly. This will help later.

lavr2016 · Answer

Hello! You can use library from github: https://github.com/kontakt/MAX30100 I work with Arduino pro mini(atmega328), communication is ok. (are you know, the I2C voltage for MAX30100 <=3.6 Volt and need a pull-up resistors ?). Also i try to connect MAX30100 and 30102 to FRDM-K64f(Freescale). I get a ADC data from MAX but can't calculate it into normal heartrate or SPO2 - heart rate change from 60-80 BPM(i think, it normal) to 180-250. May be I use an incorrect algorithm? MAXIM don't provide a sample code or appnote for this sensor (it's official response from Maxim support centre!!!) , I think it very BAD! too many sensors from another company have a lot of documentation for calculation sensor's data! good luck

Former Member · Answer

I used that library in arduino also and it also worke. I was talking about xmega 128 a3u comunnication since i want to use the max 30100 with that microprocessor. You are probably detecting false positive peaks due to noise or motion artefacts, try to use a moving average filter and a low passa filter to smooth the signal. In your algorithm try to use an adaptative treshold and guaranty that you can't detect 2 peaks too close to each other. give them a minimum distance of samples between them. And yes MAXIM should provide sample code or appnotes. Good luck

eswar123 · Answer

hi friends im new to iot and im doing a project which includes MAX 30102 can someone provide me the libraries for atmega 16a and some sample codes so it could help me alot thank you

aswinvenu · Answer

Hi Mano, Please give more information. If you have the schematics of your design please share that. MAX30102 is just an upgraded version of MAX30100. Please share the code as well. Are you referring to the 4.7KOhm pull-up resistor on the I2C line?

sendhelp · Answer

Hi so Sorry Sir, I have been very busy. I would like to thank yall for yall help. I have gotten my Max30100 component to work. Thank you very much but now i am facing a different problem. I now need to send this data via bluetooth and its very difficult. I cannot seem to send the data over through serial.write() of an arduino. Does anyone know how to do so? So sorry for this very late reply. Regards, Send Mano

how to compute heart rate and SPO2 from MAX30100

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