Gravity: MAX30102 Heart Rate and Oximeter Sensor Wiki - DFRobot

Introduction

DFRobot Gravity: MAX30102 heart rate and blood oxygen sensor module integrates the Maxim MAX30102 chip and an MCU heart rate and blood oxygen algorithm.
The MAX30102 uses PPG(PhotoPlethysmoGraphy) to measure data, which will be converted into heart rate and oximetry values when processed by the MCU, then output through I2C or UART, making the sensor easy to use and greatly reducing resource occupation of main controller. Meanwhile, the corresponding upper computer is provided to allow you to conveniently read data by a PC.

Note:

1. The pressure may change when the finger is directly pressed down the sensor, which will affect the data output. So please try to fix the sensor on your finger.
2. Wear the sensor on your finger and there is no difference in the direction of wearing.
3. This product is not a professional medical instrument and should not be used as an auxiliary accessory in diagnosis and treatment.

Features

• Microcontroller with integrated algorithm
• Data can be read directly through the host computer

Applications

• Heart rate blood oxygen project
• Home heart rate oximeter
• Long-term heart rate and blood oxygen monitoring project

Specification

• Power Supply Voltage: 3.3V/5V
• Working Current: <15mA
• Communication Method: I2C/UART
• I2C Address: 0x57
• Serial Port Baud Rate: 9600
• Operating Temperature Range: -40℃~85℃
• Product Size: 25.5×32mm/0.98×1.26inch

Wear Instructions

Board Overview

Tutorial

Requirements

• Hardware
  • DFRduino UNO R3 (or similar) x 1
  • Gravity: MAX30102 heart rate blood oxygen sensor x1
  • Dupont wires

• Software
  • Arduino IDE
  • RTU Library
  • Download and install the Heart Rate Sensor Library and Sample Codes Library (About how to install the library?)

Note: RTU library is the modbus library transplanted for Arduino based on Modbus RTU protocol. Install the RTU library before use.

Connection Diagram

Sample Code 1 - Get the Heart Rate and Blood Oxygen Data

Obtain the heart rate blood oxygen value, start measuring the heart rate when the sensor's red light is on, the heart rate data is updated every 4 seconds, the sensor data can still be obtained within 4 seconds, but the data obtained during the data update period does not change.
Please pay attention to the position of the communication switch.

/*!
  * @file  gainHeartbeatSPO2.ino
  * @n experiment phenomena: get the heart rate and blood oxygenation, during the update the data obtained does not change
  * @copyright   Copyright (c) 2010 DFRobot Co.Ltd (http://www.dfrobot.com)
  * @licence     The MIT License (MIT)
  * @author      PengKaixing(kaixing.peng@dfrobot.com)
  * @version     V1.0
  * @date        2021-06-21
  * @get         from https://www.dfrobot.com
  * @url         https://github.com/DFRobot/DFRobot_BloodOxygen_S
*/
#include "DFRobot_BloodOxygen_S.h"

#define I2C_COMMUNICATION  //use I2C for communication, but use the serial port for communication if the line of codes were masked

#ifdef  I2C_COMMUNICATION
#define I2C_ADDRESS    0x57
  DFRobot_BloodOxygen_S_I2C MAX30102(&Wire ,I2C_ADDRESS);
#else
/* ---------------------------------------------------------------------------------------------------------------
 *    board   |             MCU                | Leonardo/Mega2560/M0 |    UNO    | ESP8266 | ESP32 |  microbit  |
 *     VCC    |            3.3V/5V             |        VCC           |    VCC    |   VCC   |  VCC  |     X      |
 *     GND    |              GND               |        GND           |    GND    |   GND   |  GND  |     X      |
 *     RX     |              TX                |     Serial1 TX1      |     5     |   5/D6  |  D2   |     X      |
 *     TX     |              RX                |     Serial1 RX1      |     4     |   4/D7  |  D3   |     X      |
 * ---------------------------------------------------------------------------------------------------------------*/
#if defined(ARDUINO_AVR_UNO) || defined(ESP8266)
SoftwareSerial mySerial(4, 5);
DFRobot_BloodOxygen_S_SoftWareUart MAX30102(&mySerial, 9600);
#else
DFRobot_BloodOxygen_S_HardWareUart MAX30102(&Serial1, 9600); 
#endif
#endif

void setup()
{
  Serial.begin(115200);
  while (false == MAX30102.begin())
  {
    Serial.println("init fail!");
    delay(1000);
  }
  Serial.println("init success!");
  Serial.println("start measuring...");
  MAX30102.sensorStartCollect();
}

void loop()
{
  MAX30102.getHeartbeatSPO2();
  Serial.print("SPO2 is : ");
  Serial.print(MAX30102._sHeartbeatSPO2.SPO2);
  Serial.println("%");
  Serial.print("heart rate is : ");
  Serial.print(MAX30102._sHeartbeatSPO2.Heartbeat);
  Serial.println("Times/min");
  Serial.print("Temperature value of the board is : ");
  Serial.print(MAX30102.getTemperature_C());
  Serial.println(" ℃");
  //The sensor updates the data every 4 seconds
  delay(4000);
  //Serial.println("stop measuring...");
  //MAX30102.sensorEndCollect();
}

Expected Results

API Function

/*!
 *  @brief Get heart rate and oxygen saturation and store them into the structure sHeartbeatSPO2
 *  @param NULL
 *  @return No value returned
 */
    void getHeartbeatSPO2();

/*!
 *  @brief Get the sensor board temp
 *  @param NULL
 *  @return Temp (unit: ℃)
 */
    float getTemperature_C();

/*!
 *  @brief Sensor starts to collect data
 *  @param NULL
 *  @return NULL
 */
    void sensorStartCollect();

/*!
 *  @brief Sensor stops collecting data
 *  @param NULL
 *  @return NULL
 */
    void sensorEndCollect();

Tutorial for Raspberry Pi

Requirements

• Hardware
  • Raspberry Pi 4B (or similar) x1
  • Heart Rate and Oximeter Sensor V2 module (compatible with Raspberry Pi) x1
  • Wires

• Software
  • Heart Rate Sensor Python Library
  • RASPBIAN Raspberry Pi Official Operating System

Connection Diagram

• Connect the module to Raspberry Pi according to the connection diagram. The default I2C address is 0x68.

Driver Installation

1. Enable the I2C interface of Raspberry Pi, if enabled, skip this step. Open terminal, type the following command, and press Enter:

pi@raspberrypi:~ $ sudo raspi-config

Select "5 Interfacing Options" and press Enter. Select "P5 I2C" and press Enter to confirm "YES". Restart the Raspberry Pi master control.

2. Install Python dependencies with git, and Raspberry Pi needs to be connected to the Internet. If done, skip this step. In the terminal, type the following commands and press Enter:

pi@raspberrypi:~ $ sudo apt-get update

pi@raspberrypi:~ $ sudo apt-get install build-essential python-dev python-smbus git

3. Download the BloodOxygen driver libraries. In the terminal, type the following commands and press Enter:

pi@raspberrypi:~ $ cd Desktop/ pi@raspberrypi:~/Desktop $ git clonehttps://github.com/DFRobot/DFRobot_BloodOxygen_S

Sample Code 1 - Get the Heart Rate and Blood Oxygen Data (gain_heartbeat_SPO2.py)

• In the terminal, type the following command and press Enter to run the sample code:

pi@raspberrypi:~/Desktop $ cd DFRobot_BloodOxygen_S/python/raspberry/example/gain_heartbeat_SPO2/

pi@raspberrypi:~/Desktop/DFRobot_BloodOxygen_S/python/raspberry/example/gain_heartbeat_SPO2/ $ python gain_heartbeat_SPO2.py

• Result

Use Guide for the Master Computer

Connect the sensor to the USB-to-serial port module.

Click to download the master computer of SEN0344 Heart Rate and Oximeter Sensor.

After decompressing, run SEN0344.exe, select the serial port and baud rate and click to start the measurement.

Modbus RTU Protocols

Note: The communication interface uses UART

CRC check

static uint16_t calculate_CRC(uint8_t *data, uint8_t len)
{
  uint16_t crc = 0xFFFF;
  for( uint8_t pos = 0; pos < len; pos++)
  {
    crc ^= (uint16_t)data[ pos ];
    for(uint8_t i = 8; i != 0; i--)
    {
      if((crc & 0x0001) != 0){
        crc >>= 1;
        crc ^= 0xA001;
      }else{
        crc >>= 1;
      }
    }
  }
  crc = ((crc & 0x00FF) << 8) | ((crc & 0xFF00) >> 8);
  return crc;
}

FAQ

For any questions, advice or cool ideas to share, please visit the DFRobot Forum.

More Documents

• SEN0518-Schematics.pdf
• SEN0518-Dimension.pdf
• MAX30102 Datasheet