Arduino Usage Tutorial

Sensor Introduction

JUXI_HeartRate_SPO2 is a heart rate & SpO2 sensor module based on the MAX30102 chip, with a built-in algorithm that can directly output heart rate and blood oxygen saturation values.

Main features:

• Blood oxygen saturation (SPO2) measurement
• Heart rate measurement (beats/minute)
• Onboard temperature measurement
• Supports I2C communication

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Arduino Usage Tutorial

Hardware Preparation

Required materials
Arduino board (Uno/ESP32, etc.)
JUXI_HeartRate_SPO2 sensor
Several jumper wires
USB cable (to connect the Arduino to the computer)

Library Installation

1. Download the library file JUXI_HeartRate_SPO2.zip
2. Extract the archive and copy it to the Arduino libraries directory:

• Windows: C:\Users\<username>\Documents\Arduino\libraries\
• Mac: ~/Documents/Arduino/libraries/
• Linux: ~/Arduino/libraries/

1. Restart the Arduino IDE

Example Code Upload

Note: when uploading code, connect only the Arduino to the computer; do not connect the heart rate & SpO2 sensor to the Arduino!

Option 1: UART Mode Example

Comment out #define I2C_COMMUNICATION and upload the code to the Arduino

#include "JUXI_HeartRate_SPO2.h"

// I2C 地址
#define I2C_ADDRESS 0x57

// 创建传感器对象，I2C模式
JUXI_HeartRate_SPO2_I2C sensor(&Wire, I2C_ADDRESS);

void setup() {
  Serial.begin(9600);

  // 初始化传感器
  while (!sensor.begin()) {
    Serial.println("传感器初始化失败，请检查连接！");
    delay(1000);
  }
  Serial.println("传感器初始化成功！");

  // 启动数据采集
  sensor.sensorStartCollect();
}

void loop() {
  // 读取心率和血氧数据
  sensor.getHeartbeatSPO2();

  // 输出血氧饱和度
  Serial.print("血氧饱和度: ");
  Serial.print(sensor._sHeartbeatSPO2.SPO2);
  Serial.println(" %");

  // 输出心率
  Serial.print("心率: ");
  Serial.print(sensor._sHeartbeatSPO2.Heartbeat);
  Serial.println(" 次/分钟");

  // 读取并输出温度
  Serial.print("板载温度: ");
  Serial.print(sensor.getTemperature_C());
  Serial.println(" ℃");

  Serial.println("------------------------");

  // 传感器每4秒更新一次数据
  delay(4000);
}

Hardware Connection

I2C communication

Sensor pin	Arduino
VCC	5V/3.3V
GND	GND
SDA	SDA/A4
SCL	SCL/A5

• Slide the switch on the heart rate & SpO2 monitoring module to IIC!!!
• Use a data cable to connect the Arduino to the computer

Running Results:

Step 1: Open Arduino - Tools - Serial Monitor

Set the baud rate to 9600

Step 2: Open the serial debugging assistant

Serial Debug Assistant uartassist5.15.zip

Select the serial port

Set the baud rate to 9600

Data bits 8, stop bit 1, parity NONE, flow control NONE

Select ASCII for both the receive settings and the send settings

API Description

Function	Description
begin()	Initialize the sensor, returns true/false
getHeartbeatSPO2()	Read heart rate and SpO2 data, stored in the _sHeartbeatSPO2 struct
getTemperature_C()	Read the onboard temperature (degrees Celsius)
sensorStartCollect()	Start data collection (sensor LED on)
sensorEndCollect()	Stop data collection (sensor LED off)

Data Notes

• SPO2 (blood oxygen saturation): normal range 95% - 100%; a value of -1 indicates invalid data
• Heartbeat: normal range 60 - 100 beats/minute; a value of -1 indicates invalid data
• Causes of invalid values: finger not placed properly or data not yet stable

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Usage Precautions

Measurement Tips

1. Place your finger correctly

• Place your finger gently on the sensor, covering both LEDs
• Do not press hard, so as not to affect blood circulation
• Keep your finger steady and do not move

1. Wait for the data to stabilize

• At the beginning of a measurement, the values may be unstable
• It is recommended to wait 10-30 seconds until the data is stable before reading
• The sensor updates data every 4 seconds

1. Environmental requirements

• Avoid direct strong light on the sensor
• Keep the ambient temperature comfortable
• Stay quiet during measurement

Data Interpretation

SPO2 range	Description
95% - 100%	Normal
90% - 94%	Mild hypoxemia
< 90%	Hypoxemia; consult a doctor

Heart rate range	Description
60 - 100 BPM	Normal adult range
< 60 BPM	Bradycardia
> 100 BPM	Tachycardia

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FAQ

Q1: What should I do if sensor initialization fails?

A:

1. Check whether the wiring is correct (SDA to GPIO2/A4, SCL to GPIO3/A5)
2. Confirm that the power supply is normal (3.3V or 5V)
3. Use the i2cdetect -y 1 command to detect the device
4. Confirm that the sensor switch is in the IIC position

Q2: What should I do if the data keeps showing -1?

A:

1. Confirm that your finger is placed correctly on the sensor
2. Wait a few seconds for the data to stabilize
3. Check whether sensorStartCollect() has been called to start collection
4. Confirm whether the sensor indicator LED is on

Q3: What should I do if the data is inaccurate?

A:

1. Make sure your finger completely covers the sensor's optical area
2. Keep your finger still and do not move
3. Wait at least 30 seconds for the data to stabilize
4. Take multiple measurements and average the results

Q4: Which Arduino boards does the sensor support?

A: Supports:

• Arduino Uno/Mega
• ESP8266
• ESP32
• Other boards that support the Arduino environment

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Example File Location

Arduino Example

JUXI_HeartRate_SPO2/
└── examples/
    └── gainHeartbeatSPO2/
        └── gainHeartbeatSPO2.ino