RCWL 0530 (MAX30100 pulsemeter and heart beat detector i2c reading problem

hi eveyone im trying to build a pulsemeter with max30100 module . but it doesnt work properly. here it is the code, schematic and other things https://github.com/oxullo/Arduino-MAX30100

the circuit didnt work with those instructions in that link. first of all , it doesnt work with 3.3v . it couldnt turn the red led on. then i connected Vin to 5v .after that i got the first results. the red led turned on. and also i used two pull up resistors for scl and sda pins.

now , my problem is when i put my finger on the sensor it doesnt detect the beats . it shows " Heart rate:0.00bpm / SpO2:0% ". but when i pull my finger back (i keep my finger on the sensor but there are about 2 or 3 cms between my finger and the sensor) it starts to detect the beats. values are not right but it can detect the beat anyway. here they are ,some results : "Heart rate:81.67bpm / SpO2:95% Beat! Heart rate:77.89bpm / SpO2:95% Heart rate:77.89bpm / SpO2:95% Beat! Heart rate:88.38bpm / SpO2:95% Beat! Beat! Heart rate:150.46bpm / SpO2:95% Heart rate:150.46bpm / SpO2:95% Heart rate:0.00bpm / SpO2:0% Beat! Beat! Heart rate:139.43bpm / SpO2:0% Beat! Heart rate:148.61bpm / SpO2:95% Beat! Heart rate:142.83bpm / SpO2:95% Heart rate:142.83bpm / SpO2:95% Beat! Heart rate:92.51bpm / SpO2:0% Heart rate:92.51bpm / SpO2:0% Beat! Heart rate:67.55bpm / SpO2:0% Heart rate:67.55bpm / SpO2:0% " normally it was supposed to detect my heart beats while im keeping my finger on the sensor.but i have to hold my finger above the sensor.maybe it is because the voltage .but i dont know where i should change to adapt it for 5v (on the code or circuit ) honestly i dont know what to do right now, i tried to do my best but i couldn't find the problem.can anyone help me to fix this up ? i need to finish this project as soon as possible.i need someone who have used this sensor before or who have come across with this problem.

these are my photos of my circuit |500x375 |500x375 |500x375 |500x375

No one can help? :/

Hi Ghostmanzero, I just ordered one of those pulse oximetry sensors also so I'll be keeping an eye on this thread. I havent worked with it yet, but looking at the Max30100 datasheet, found here:


I note that on the detector module pic, there are pins for RD and IRD. On the datasheet, page 8, RD and IRD is for red led cathode and infrared led cathode. I wonder if the intensity can be adjusted through those RD and IRD pins...

A couple of updates... Take a look at the 4th comment on this page, suggests resistors needed from RD and IRD...


On this advertisement page, the seller shows the schematic of the Max30100 module. Note that RD and IRD go nowhere!