How to Use MAX30100: Examples, Pinouts, and Specs

The MAX30100 is a low-power, integrated pulse oximeter and heart-rate monitor sensor. It uses photoplethysmography (PPG) technology to measure blood oxygen saturation (SpO2) and heart rate by emitting light through the skin and detecting changes in light absorption. This compact sensor is ideal for wearable devices, fitness trackers, and medical monitoring systems.

• Wearable health monitoring devices
• Fitness trackers
• Medical-grade pulse oximeters
• Heart rate monitoring systems
• IoT health applications

The MAX30100 is designed for low-power operation and high accuracy. Below are its key technical details:

The MAX30100 has 14 pins, but only a subset is typically used in most applications. Below is the pin configuration:

The MAX30100 is straightforward to use in a circuit, especially with microcontrollers like the Arduino UNO. Below are the steps to integrate and use the sensor:

1. Wiring:

   • Connect the SDA pin of the MAX30100 to the Arduino's A4 pin.
   • Connect the SCL pin of the MAX30100 to the Arduino's A5 pin.
   • Connect the VIN pin of the MAX30100 to the Arduino's 3.3V pin.
   • Connect the GND pin of the MAX30100 to the Arduino's GND pin.
   • Optionally, connect the INT pin to a digital pin on the Arduino for interrupt-based operation.

2. Install Required Libraries:

   • Use the Arduino IDE Library Manager to install the "MAX30100" library or download it from a trusted source like GitHub.

3. Sample Code: Below is an example Arduino sketch to read heart rate and SpO2 data from the MAX30100:

   #include <Wire.h>
   #include "MAX30100_PulseOximeter.h"
   
   // Create an instance of the PulseOximeter class
   PulseOximeter pox;
   
   // Variable to store the last update time
   uint32_t lastUpdate = 0;
   
   // Callback function to handle new data
   void onBeatDetected() {
       Serial.println("Beat detected!");
   }
   
   void setup() {
       // Initialize serial communication
       Serial.begin(9600);
       Serial.println("Initializing MAX30100...");
   
       // Initialize the MAX30100 sensor
       if (!pox.begin()) {
           Serial.println("Failed to initialize MAX30100. Check connections!");
           while (1);
       }
   
       // Set the callback for beat detection
       pox.setOnBeatDetectedCallback(onBeatDetected);
   
       Serial.println("MAX30100 initialized successfully.");
   }
   
   void loop() {
       // Update the sensor readings
       pox.update();
   
       // Print data every 1 second
       if (millis() - lastUpdate > 1000) {
           lastUpdate = millis();
           Serial.print("Heart Rate: ");
           Serial.print(pox.getHeartRate());
           Serial.print(" bpm, SpO2: ");
           Serial.print(pox.getSpO2());
           Serial.println(" %");
       }
   }
   

• Power Supply: Ensure the sensor is powered with a stable 3.3V supply. Avoid using 5V as it may damage the sensor.
• I2C Pull-Up Resistors: The I2C lines (SDA and SCL) require pull-up resistors (typically 4.7kΩ). Some breakout boards include these resistors; check your board's documentation.
• Ambient Light: Minimize ambient light interference by enclosing the sensor in a dark environment or using it in low-light conditions.
• Skin Contact: For accurate readings, ensure the sensor is in firm contact with the skin, preferably on a fingertip or earlobe.

1. No Data Output:

   • Verify the wiring connections, especially the SDA and SCL lines.
   • Ensure the I2C address (0x57) matches the library or code configuration.

2. Inaccurate Readings:

   • Check for proper skin contact with the sensor.
   • Reduce ambient light interference by shielding the sensor.

3. Sensor Not Detected:

   • Confirm that the MAX30100 is powered correctly (3.3V).
   • Use an I2C scanner sketch to verify the sensor's address.

4. Intermittent Data:

   • Ensure the I2C pull-up resistors are present and correctly valued.
   • Check for loose connections or poor soldering.

Q: Can the MAX30100 measure SpO2 and heart rate simultaneously?
A: Yes, the MAX30100 can measure both SpO2 and heart rate simultaneously. However, ensure the sensor is properly configured in your code.

Q: What is the maximum sampling rate of the MAX30100?
A: The MAX30100 supports a programmable sampling rate of up to 100 Hz.

Q: Can I use the MAX30100 with a 5V microcontroller?
A: Yes, but you must use a logic level shifter to convert the 5V I2C signals to 3.3V to avoid damaging the sensor.

Q: How do I improve measurement accuracy?
A: Ensure proper skin contact, minimize motion, and reduce ambient light interference for the best results.