My GY-MAX30100 pulse oximeter issue with Arduino Uno I connected the purple oximeter (GY-MAX30100) to the Arduino Uno with the following connections. 

OXIMETER       ARDUINO UNO
VIN              5V
GND              GND
SCL              SCL
SDA              SDA
INT              D2


It shows me inaccurate measurements.

13:16:02.851 -&gt; Pulse oxymeter test!
13:16:02.851 -&gt; BEAT
13:16:02.851 -&gt; BPM: 8616.35 | SaO2: 92.01%
13:16:03.055 -&gt; BEAT
13:16:03.055 -&gt; BPM: 4313.73 | SaO2: 92.66%
13:16:03.089 -&gt; BEAT
13:16:03.089 -&gt; BPM: 1209.15 | SaO2: 92.74%


I used this sketch from github
https://github.com/xcoder123/MAX30100/blob/master/max30100.ino

This is the sensor

EDIT

I have run an I2C scanner and this is the result: I2C device found on address 0x57. The library has the same address hard coded in it.
There are 2 newer libraries you can try. I have used both with a MAX30102 and they work.

The first one is here: SparkFun_MAX3010x_Sensor_Library. There are several sketches included, and this one worked for me: Example5_HeartRate.

The other library I had success with is this one: Protocentral. It has a test sketch that writes the data to the serial port, but you can add Serial.println() statements to it to see if the data "makes sense".