MAX30102 Pulse Oximeter Heart Rate Sensor Module

What this module is

The MAX30102 is a biometric sensor used to measure:

• Heart Rate (BPM)

• Blood Oxygen Saturation (SpO)

It uses optical sensing (PPG Photoplethysmography), shining light into your skin and measuring reflected signals.

Key Specifications

• Sensor type: Optical pulse oximeter (Red + IR LEDs)

• Measurements: Heart rate + SpO

• Interface: I2C (up to 400 kHz)

• Operating voltage: 3.3V5V (module), core ~1.8V

• ADC resolution: up to 18-bit

• Current consumption: ~600A1.2mA (active)

• Shutdown current: ~0.7A (very low power)

• High accuracy with ambient light cancellation

• FIFO buffer (reduces MCU load)

• Motion artifact reduction (better readings)

• Ultra-low power ideal for wearables

• Built-in temperature sensor (for calibration)

Pinout (Typical)

• VIN / VCC 3.3V or 5V

• GND Ground

• SDA I2C Data

• SCL I2C Clock

• INT Interrupt (optional)

I2C address: usually 0x57

Working Principle (simple)

• Red (660nm) & IR (880nm) light pass alculates SpO + pulse rate from variations

Applications

• Smartwatches / fitness bands

• DIY pulse oximeters

• Health monitoring systems

• IoT healthcare projects

• Biomedical research

Important Notes (very important)

• Finger placement matters a lot (stable contact needed)

• Not medical-grade accuracy (DIY use)

• Needs filtering + algorithm for correct BPM/SpO

• LEDs won't glow unless initialized in code (common beginner issue)

Many beginners think the sensor is faulty when LED doesn't turn on'actually you must configure registers in code first (very common issue in practice).

MAX30102 vs MAX30100

Higher

When to use this

Use MAX30102 if you want:

• Accurate heart rate sensing

• SpO monitoring projects

• Wearable / IoT healthcare systems<