2pcs MAX30102 Heart Rate Sensor Module Heart beat Frequency Tester for Arduino

Here are some useful links on the documentation for this Heart Rate Module: 

1. https://www.hackster.io/SurtrTech/measure-heart-rate-and-spo2-with-max30102-c2b4d8; 
2. https://pdfserv.maximintegrated.com/en/an/AN6409.pdf; 
3. https://drive.google.com/open?id=1CNQe2Z9qPuh5BIPQZTv-oPyTrjssJAXF

The Main Parameters:
LED peak wavelength: 660nm/880nm
LED power supply voltage: 3.3~5V
Detection signal type: light reflection signal (PPG)
Output signal interface : I2C interface
Communication interface voltage: 1.8~3.3V~5V (optional)
Board reserved assembly hole size: 0.5 x 8.5mm

Pin Description:
VIN: main power input terminal 1.8-5V
3-bit pad: Select the pull-up level of the bus, depending on the pin master voltage, select 1.8v or 3_3v (this terminal contains 3.3V and above)
SCL: the clock connected to the I2C bus;
SDA: data connected to the I2C bus;
INT: Interrupt pin of the MAX30102 chip;
RD: RED LED ground terminal of MAX30102 chip, generally not connected;
IRD: The IR LED ground of the MAX30102 chip is generally not connected;
GND: Ground wire.

Principle Description:
Light-dissolving method: measuring the pulse and blood oxygen saturation by using human tissue to cause different transmittance when the blood vessel beats;
Light source: a specific wavelength of light-emitting diode selective for oxyhemoglobin (H bO 2 ) and hemoglobin ( Hb ) in arterial blood;
The transmittance is converted into an electrical signal: the change in the volume of the arterial pulsation causes a change in the transmittance of the light. At this time, the 
photoelectric variator receives the reflected light from the human tissue, converts it into an electrical signal, and amplifies and outputs it.

Package Included:
1pcs MAX30102 Heart Rate Sensor Module