Heart Rate & SpO₂ Sensor (MAX30100/MAX30102)

🔬 Pulse Sensor | SpO₂ Monitor | Wearable Health Tech

The MAX30100/MAX30102 is a digital pulse oximeter and heart-rate sensor developed by Maxim Integrated. It’s commonly used in fitness bands, medical devices, and IoT-based health monitoring systems. It combines two key measurements in one module: heart rate (BPM) and blood oxygen saturation (SpO₂ %).

🔧 Key Features

🧠 How It Works

1. Heart Rate Measurement

• The infrared LED emits light into the finger or skin.
• A photodetector measures the reflection, which varies with each heartbeat due to blood flow changes.
• The waveform is analyzed to detect pulse and compute beats per minute (BPM).

2. SpO₂ Measurement

• Uses red and infrared light to measure the ratio of oxygenated to deoxygenated hemoglobin.
• The light absorption difference gives an estimate of oxygen saturation in the blood.

🔌 Connections (I²C Mode)

📦 Typical Applications

• 🧠 Health and fitness trackers
• 📟 Wearable health monitors
• 🏥 Remote patient monitoring systems
• 📱 Mobile health applications
• 🧪 Biomedical IoT projects
• 🚨 Emergency health alert systems

📌 Note: Place your finger gently and keep it still for accurate readings.

📌 Notes

• Avoid bright ambient light or motion for stable readings.
• Use a rubber band or clip to hold your finger steady.
• Some modules need a small delay after pox.begin() to stabilize readings.
• Suitable for wearable applications and long-term monitoring.

HOW TO OPERATE

#include <Wire.h>
#include "MAX30100_PulseOximeter.h"

#define REPORTING_PERIOD_MS 1000

PulseOximeter pox;
uint32_t tsLastReport = 0;

void onBeatDetected() {
Serial.println("❤️ Beat Detected!");
}

void setup() {
Serial.begin(115200);
Serial.println("Initializing MAX30100 sensor...");

if (!pox.begin()) {
Serial.println("MAX30100 not detected. Please check connections.");
while (1);
}

pox.setOnBeatDetectedCallback(onBeatDetected);
}

void loop() {
pox.update();

if (millis() - tsLastReport > REPORTING_PERIOD_MS) {
Serial.print("Heart Rate: ");
Serial.print(pox.getHeartRate());
Serial.print(" BPM | SpO2: ");
Serial.print(pox.getSpO2());
Serial.println(" %");

tsLastReport = millis();
}
}

#include <Wire.h>
#include "MAX30100_PulseOximeter.h"

#define REPORTING_PERIOD_MS 1000

PulseOximeter pox;
uint32_t tsLastReport = 0;

void onBeatDetected() {
Serial.println("❤️ Beat Detected!");
}

void setup() {
Serial.begin(115200);
Serial.println("Initializing MAX30100 sensor...");

if (!pox.begin()) {
Serial.println("MAX30100 not detected. Please check connections.");
while (1);
}

pox.setOnBeatDetectedCallback(onBeatDetected);
}

void loop() {
pox.update();

if (millis() - tsLastReport > REPORTING_PERIOD_MS) {
Serial.print("Heart Rate: ");
Serial.print(pox.getHeartRate());
Serial.print(" BPM | SpO2: ");
Serial.print(pox.getSpO2());
Serial.println(" %");

tsLastReport = millis();
}
}