MAX30100 Heart Rate and SpO2 Sensor Module I2C 1.8-5.5V

Product Description

This compact sensor module integrates the MAX30100, a pulse oximeter and heart-rate monitoring IC combining red/infrared LEDs, a photodetector, and analog signal processing — all in a single chip. It measures both SpO2 (blood oxygen saturation) and heart rate using reflected light from a fingertip or earlobe.

To keep things simple, the module includes onboard regulators that generate both required supply voltages from a single external input:

• Accepts 1.8V to 5.5V input at the VIN pin
• Internally creates 3.3V for the LED drivers
• Steps this down again to 1.8V for the chip’s core and logic

Important note:

The MAX30100 operates at 1.8V logic level. This is not directly compatible with 3.3V or 5V logic (Arduino, ESP32, STM32, etc.).
You must use a level shifter (like this one) to safely interface with most microcontrollers over I2C.

I2C Details:

• 7-bit I2C address: 0x57
• 8-bit (Arduino-style) write address: 0xAE
• 8-bit read address: 0xAF

Library for Arduino IDE:

Use the open-source library from SparkFun (tested and reliable)

Features:

• Measures heart rate and SpO2 using reflected red and IR light
• Onboard voltage regulation from 1.8V to 5.5V input
• Integrated photodiode, ADC, LED drivers, and filtering
• Built-in ambient light cancellation and FIFO buffer
• I2C communication with INT (interrupt) output
• Ultra-low power operation for wearable applications

Pinout (7-pin header):

• VIN – Input voltage (1.8V–5.5V)
• GND – Ground
• SDA – I2C data (1.8V level)
• SCL – I2C clock (1.8V level)
• INT – Data-ready interrupt output (1.8V level)
• IRD – IR LED cathode (direct sensor pin - leave open)
• RD – Red LED cathode (direct sensor pin - leave open)