MAX30100 is an integrated pulse oximeter and heart-rate sensor developed by Maxim Integrated (now part of Analog Devices). It combines LEDs, a photodetector, optical components, and low-noise electronics into a single chip for measuring heart rate (HR) and blood oxygen saturation (SpO₂).
VIN:Power supply (typically 3.3 V–5 V on breakout boards)
GND:Ground
SDA:I²C data
SCL:I²C clock
INT:Interrupt output (optional)
The MAX30100 uses a technique called photoplethysmography (PPG):
The red and infrared LEDs shine light into a fingertip, earlobe, or wrist.
Blood absorbs different amounts of red and infrared light depending on its oxygen level.
The photodetector measures the reflected or transmitted light.
The sensor's internal circuitry processes the signals and sends digital data to a microcontroller through the I²C interface.
Software calculates:
Heart rate (BPM)
Blood oxygen level (SpO₂)
Applications
The MAX30100 is commonly used in:
Pulse oximeters
Heart-rate monitors
Wearable fitness devices
Smartwatches
Health-monitoring systems
IoT healthcare projects
Patient monitoring prototypes