Arduino algorithms or codes for SpO2 (blood oxygen saturation level)

Hi, I am really new here, and I have a project which is a pulse oxymeter and I am using TCRT5000 which is a IR led and photo transistor in a leaded package, and I also use an RED led for the SpO2 acquisition, I already manage to have a decent output for my heartrate using the 'FreqMeasure' library and now I'm stuck with the SpO2, I dont have great background and foundation with arduino so bear with me. I just want to ask some help with the codes/ algorithms for this parameter please. Hoping for your good advices it would really be a big help. Based on some articles that I read, Ratio = (log((ACred+DCred)/(DCred)))/(log((ACir+DCir)/(DCir))) and after getting the ratio SpO2 can be solved by this formula S = 110-25*R and there are also some with R/IR = (ACr/DCr)/(ACir/DCir). but the problem is I don't know much how to formulate my own codes, tho I constructed a code for simultaneous ON & OFF of the red and ir LED's, I have no idea what to do next how do I acquire those datas' to solve those formulas above?. In dire need of help. Thank you!

Why not use an MAX30100? That is optimized for that precise purpose, and will do a better job than a general purpose color sensor...

how I wish I could use a module, but unfortunately my professor requires us to use tcrt5000 and doesn't allow us to use any module, we are even asked to build the circuit on our own. :frowning: :frowning: he gives strict instructions and yet teach us how the process goes, he just provide us the schematic.