How to Use MAX30102: Examples, Pinouts, and Specs

The MAX30102 is a pulse oximeter and heart-rate sensor designed for non-invasive health monitoring applications. It utilizes photoplethysmography (PPG) technology to measure blood oxygen saturation (SpO2) and heart rate. The sensor integrates red and infrared LEDs, a photodetector, optical elements, and low-noise electronics in a compact package, making it ideal for wearable devices, fitness trackers, and medical monitoring systems.

• Wearable health monitoring devices
• Fitness trackers
• Medical-grade pulse oximeters
• Remote patient monitoring systems
• IoT-based health solutions

The MAX30102 is a highly integrated sensor with the following key specifications:

The MAX30102 has 8 pins, as described in the table below:

1. Power Supply: Connect the VIN pin to a 1.8V or 3.3V power source and the GND pin to ground.
2. I2C Communication: Connect the SDA and SCL pins to the corresponding I2C pins on your microcontroller. Use pull-up resistors (typically 4.7 kΩ) on both lines.
3. Interrupt Pin: Optionally, connect the INT pin to a GPIO pin on your microcontroller to handle interrupts.
4. LED Control: The red and infrared LEDs are internally connected and controlled by the MAX30102 firmware.

• Ambient Light: Minimize ambient light interference by enclosing the sensor in a dark housing.
• Placement: Ensure proper skin contact for accurate readings. The sensor should be placed on a fingertip or earlobe for best results.
• Power Management: Use low-power modes when the sensor is idle to conserve energy in battery-powered applications.

Below is an example of how to interface the MAX30102 with an Arduino UNO to read heart rate and SpO2 data:

#include <Wire.h>
#include "MAX30105.h" // Include the MAX30102 library

MAX30105 particleSensor; // Create an instance of the sensor

void setup() {
  Serial.begin(9600); // Initialize serial communication
  Serial.println("Initializing MAX30102...");

  // Initialize the sensor
  if (!particleSensor.begin()) {
    Serial.println("MAX30102 not detected. Check connections.");
    while (1); // Halt execution if the sensor is not found
  }

  // Configure the sensor
  particleSensor.setup(); // Default settings
  particleSensor.setPulseAmplitudeRed(0x0A); // Set red LED brightness
  particleSensor.setPulseAmplitudeIR(0x0A);  // Set IR LED brightness
}

void loop() {
  // Read data from the sensor
  long redValue = particleSensor.getRed(); // Red LED value
  long irValue = particleSensor.getIR();   // IR LED value

  // Print the values to the serial monitor
  Serial.print("Red: ");
  Serial.print(redValue);
  Serial.print(" IR: ");
  Serial.println(irValue);

  delay(100); // Delay for stability
}

• Install the SparkFun MAX3010x Pulse Oximeter and Heart Rate Sensor Library from the Arduino Library Manager before running the code.
• Adjust the LED brightness and sampling rate as needed for your application.

1. Sensor Not Detected:

   • Ensure the I2C connections (SDA, SCL) are correct.
   • Verify that the I2C pull-up resistors are in place.
   • Check the sensor's power supply voltage.

2. Inaccurate Readings:

   • Ensure proper skin contact with the sensor.
   • Minimize ambient light interference by using a dark enclosure.
   • Verify that the LED brightness is appropriately configured.

3. No Data Output:

   • Confirm that the correct I2C address (0x57) is being used.
   • Check the interrupt pin connection if interrupts are enabled.

• Use an I2C scanner sketch to verify the sensor's address.
• Monitor the power supply voltage to ensure it is stable.
• Test the sensor with a known working microcontroller to rule out hardware issues.

By following this documentation, you should be able to successfully integrate and use the MAX30102 in your projects.