基于STM32设计的人体健康检测仪

时间：11-07来源：作者：点击数：32

一、项目介绍

当前文章介绍基于STM32设计的人体健康检测仪。设备采用STM32系列MCU作为主控芯片，配备血氧浓度传感器（使用MAX30102血氧浓度检测传感器）、OLED屏幕和电池供电等外设模块。设备可以广泛应用于医疗、健康等领域。可以帮助医生和病人更好地了解病情变化，提高治疗效果和生活质量。设备也可以用于健康管理、运动监测等场景，帮助用户了解自己的身体状况，保持健康的生活方式。

在项目中，使用了KEIL作为开发平台和工具，通过血氧模块采集人体的心跳和血氧浓度参数，并通过OLED屏幕显示现在的心跳和血氧浓度。同时，通过指标分析，提供采集到的数据与正常指标比对，分析被检测人员的健康状态。采集的数据可通过蓝牙或者WIFI传递给手机APP进行处理，方便用户随时了解自己的身体状况。

本设计采用STM32为主控芯片，搭配血氧浓度传感器和OLED屏幕，实现了人体健康数据的采集和展示，并对采集到的数据进行分析，判断被检测人员的健康状态。同时，设计使用蓝牙或WiFi将采集到的数据传递给手机APP进行处理。

二、项目设计思路

2.1 硬件设计

（1）主控芯片：STM32系列MCU，负责驱动其他外设模块；

（2）血氧浓度传感器：使用MAX30102血氧浓度检测传感器，用于采集人体的心跳和血氧浓度参数；

（3）OLED屏：用于显示现在的心跳和血氧浓度；

2.2 软件设计

(1) 通过血氧模块采集人体的心跳和血氧浓度参数；

(2) 通过OLED屏显示现在的心跳和血氧浓度；

(3) 对采集到的数据进行指标分析，将采集到的数据与正常指标比对，分析被检测人员的健康状态；

(4) 采集的数据可通过蓝牙或WiFi传递给手机APP进行处理。

2.3 技术实现

（1）设计采用AD8232心电图（ECG）模块和MAX30102血氧模块采集心跳和血氧浓度参数，并通过I2C接口连接主控芯片STM32。

（2）OLED屏使用I2C接口与主控芯片STM32连接。

（3）采集到的数据通过算法进行指标分析，将采集到的数据与正常指标比对，判断被检测人员的健康状态。

（4）设备通过蓝牙或WiFi将采集到的数据传递给手机APP进行处理。

三、代码设计

3.1 MAX30102血氧模块代码

I2C协议代码：

#define MAX30102_I2C_ADDR 0xAE

void MAX30102_I2C_Init(void)
{
    GPIO_InitTypeDef  GPIO_InitStructure;
    I2C_InitTypeDef   I2C_InitStructure;

    /* Enable GPIOB clock */
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
    /* Enable I2C1 and I2C2 clock */
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1 | RCC_APB1Periph_I2C2, ENABLE);

    // Configure I2C SCL and SDA pins
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD; // Open-drain output
    GPIO_Init(GPIOB, &GPIO_InitStructure);

    // Configure I2C parameters
    I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
    I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
    I2C_InitStructure.I2C_OwnAddress1 = 0x00;
    I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
    I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
    I2C_InitStructure.I2C_ClockSpeed = 100000; // 100KHz
    I2C_Init(I2C1, &I2C_InitStructure);

    // Enable I2C
    I2C_Cmd(I2C1, ENABLE);
}

void MAX30102_I2C_WriteReg(uint8_t reg, uint8_t value)
{
    while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));

    I2C_GenerateSTART(I2C1, ENABLE);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));

    I2C_Send7bitAddress(I2C1, MAX30102_I2C_ADDR, I2C_Direction_Transmitter);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));

    I2C_SendData(I2C1, reg);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

    I2C_SendData(I2C1, value);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

    I2C_GenerateSTOP(I2C1, ENABLE);
}

uint8_t MAX30102_I2C_ReadReg(uint8_t reg)
{
    uint8_t value;

    while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));

    I2C_GenerateSTART(I2C1, ENABLE);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));

    I2C_Send7bitAddress(I2C1, MAX30102_I2C_ADDR, I2C_Direction_Transmitter);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));

    I2C_SendData(I2C1, reg);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

    I2C_GenerateSTART(I2C1, ENABLE);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));

    I2C_Send7bitAddress(I2C1, MAX30102_I2C_ADDR, I2C_Direction_Receiver);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));

    I2C_AcknowledgeConfig(I2C1, DISABLE);
    value = I2C_ReceiveData(I2C1);

    I2C_GenerateSTOP(I2C1, ENABLE);

    return value;
}

void MAX30102_I2C_ReadArray(uint8_t reg, uint8_t* data, uint8_t len)
{
    while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));

    I2C_GenerateSTART(I2C1, ENABLE);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));

    I2C_Send7bitAddress(I2C1, MAX30102_I2C_ADDR, I2C_Direction_Transmitter);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));

    I2C_SendData(I2C1, reg);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

    I2C_GenerateSTART(I2C1, ENABLE);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));

    I2C_Send7bitAddress(I2C1, MAX30102_I2C_ADDR, I2C_Direction_Receiver);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));

    while(len > 1)
    {
        I2C_AcknowledgeConfig(I2C1, ENABLE);
        while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED));
        *data++ = I2C_ReceiveData(I2C1);
        len--;
    }

    I2C_AcknowledgeConfig(I2C1, DISABLE);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED));
    *data++ = I2C_ReceiveData(I2C1);

    I2C_GenerateSTOP(I2C1, ENABLE);
}

MAX30102的初始化函数和数据获取函数：

void MAX30102_Init(void)
{
    MAX30102_I2C_Init();

    // Reset the device
    MAX30102_I2C_WriteReg(0x09, 0x40);
    HAL_Delay(100);
    MAX30102_I2C_WriteReg(0x09, 0x00);

    // Set FIFO average to 4 samples
    MAX30102_I2C_WriteReg(0x08, 0x03);

    // Set LED pulse amplitude
    MAX30102_I2C_WriteReg(0x0C, 0x1F);
    MAX30102_I2C_WriteReg(0x0D, 0x1F);

    // Set sample rate to 100Hz
    MAX30102_I2C_WriteReg(0x0F, 0x04);

    // Enable the red LED only
    MAX30102_I2C_WriteReg(0x11, 0x02);

    // Read the temperature value to start a reading
    MAX30102_I2C_ReadReg(0x1F);
}

uint32_t MAX30102_GetHeartRate(void)
{
    uint8_t buffer[MAX30102_FIFO_DEPTH*4];
    MAX30102_Data sensor_data = {0};
    uint16_t ir_value;
    uint16_t red_value;
    uint8_t byte_count, fifo_overflow;

    // Check if any data is available in FIFO
    byte_count = MAX30102_I2C_ReadReg(0x06) - MAX30102_I2C_ReadReg(0x04);
    if(byte_count > 0)
    {
        fifo_overflow = MAX30102_I2C_ReadReg(0x09) & 0x80;

        // Read the data from FIFO
        MAX30102_I2C_ReadArray(0x07, buffer, byte_count);

        // Parse the data
        for(int i=0; i<byte_count; i+=4)
        {
            ir_value = ((uint16_t)buffer[i] << 8) | buffer[i+1];
            red_value = ((uint16_t)buffer[i+2] << 8) | buffer[i+3];

            // Update the sensor data
            MAX30102_UpdateData(&sensor_data, ir_value, red_value);
        }

        if(!fifo_overflow && MAX30102_CheckForBeat(sensor_data.IR_AC_Signal_Current))
        {
            return MAX30102_HeartRate(sensor_data.IR_AC_Signal_Previous, 16);
        }
    }

    return 0;
}

数据处理函数：

void MAX30102_UpdateData(MAX30102_Data* data, uint16_t ir_value, uint16_t red_value)
{
    int32_t ir_val_diff = ir_value - data->IR_AC_Signal_Current;
    int32_t red_val_diff = red_value - data->Red_AC_Signal_Current;

    // Update IR AC and DC signals
    data->IR_AC_Signal_Current = (ir_val_diff + (7 * data->IR_AC_Signal_Previous)) / 8;
    data->IR_DC_Signal_Current = (ir_value + data->IR_AC_Signal_Current + (2 * data->IR_DC_Signal_Current)) / 4;
    data->IR_AC_Signal_Previous = data->IR_AC_Signal_Current;

    // Update Red AC and DC signals
    data->Red_AC_Signal_Current = (red_val_diff + (7 * data->Red_AC_Signal_Previous)) / 8;
    data->Red_DC_Signal_Current = (red_value + data->Red_AC_Signal_Current + (2 * data->Red_DC_Signal_Current)) / 4;
    data->Red_AC_Signal_Previous = data->Red_AC_Signal_Current;

    // Update IR and Red AC signal peak-to-peak values
    if(data->IR_AC_Signal_Current > data->IR_AC_Max)
        data->IR_AC_Max = data->IR_AC_Signal_Current;
    else if(data->IR_AC_Signal_Current < data->IR_AC_Min)
        data->IR_AC_Min = data->IR_AC_Signal_Current;

    if(data->Red_AC_Signal_Current > data->Red_AC_Max)
        data->Red_AC_Max = data->Red_AC_Signal_Current;
    else if(data->Red_AC_Signal_Current < data->Red_AC_Min)
        data->Red_AC_Min = data->Red_AC_Signal_Current;
}

uint8_t MAX30102_CheckForBeat(int32_t ir_val)
{
    static uint8_t beat_detection_enabled = 1;
    static uint32_t last_beat_time = 0;
    static int32_t threshold = 0x7FFFFF;

    uint32_t delta_time;
    int32_t beat_amplitude;

    if(beat_detection_enabled)
    {
        // Increment the beat counter
        MAX30102_beat_counter++;

        // Calculate the threshold value
        threshold += (ir_val - threshold) / 8;

        // Check if a beat has occurred
        if(ir_val > threshold && MAX30102_beat_counter > 20)
        {
            delta_time = micros() - last_beat_time;
            last_beat_time = micros();
            beat_amplitude = ir_val - threshold;
            if(delta_time < 1000 || delta_time > 2000 || beat_amplitude < 20 ||
            beat_amplitude > 1000) { return 0; }
                   // Reset the beat counter and set the threshold value
        MAX30102_beat_counter = 0;
        threshold = ir_val;

        return 1;
    }
}

return 0;
}

uint32_t MAX30102_HeartRate(int32_t ir_val, uint8_t samples) { int32_t ir_val_sum = 0;
// Calculate the sum of IR values
for(int i=0; i<samples; i++)
{
    ir_val_sum += MAX30102_IR_Sample_Buffer[i];
}

// Calculate the average IR value
ir_val_sum /= samples;

// Calculate the heart rate
return (uint32_t)(60 * MAX30102_SAMPLING_FREQUENCY / (ir_val - ir_val_sum));
}

3.2 OLED显示屏驱动代码

I2C协议代码：

#define SSD1306_I2C_ADDR 0x78

void SSD1306_I2C_Init(void)
{
    GPIO_InitTypeDef  GPIO_InitStructure;
    I2C_InitTypeDef   I2C_InitStructure;

    /* Enable GPIOB clock */
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
    /* Enable I2C1 and I2C2 clock */
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1 | RCC_APB1Periph_I2C2, ENABLE);

    // Configure I2C SCL and SDA pins
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD; // Open-drain output
    GPIO_Init(GPIOB, &GPIO_InitStructure);

    // Configure I2C parameters
    I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
    I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
    I2C_InitStructure.I2C_OwnAddress1 = 0x00;
    I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
    I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
    I2C_InitStructure.I2C_ClockSpeed = 100000; // 100KHz
    I2C_Init(I2C1, &I2C_InitStructure);

    // Enable I2C
    I2C_Cmd(I2C1, ENABLE);
}

void SSD1306_I2C_WriteReg(uint8_t reg, uint8_t value)
{
    while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));

    I2C_GenerateSTART(I2C1, ENABLE);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));

    I2C_Send7bitAddress(I2C1, SSD1306_I2C_ADDR, I2C_Direction_Transmitter);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));

    I2C_SendData(I2C1, 0x00);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

    I2C_SendData(I2C1, reg);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

    I2C_SendData(I2C1, value);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

    I2C_GenerateSTOP(I2C1, ENABLE);
}

void SSD1306_I2C_WriteArray(uint8_t* data, uint16_t len)
{
    while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));

    I2C_GenerateSTART(I2C1, ENABLE);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));

    I2C_Send7bitAddress(I2C1, SSD1306_I2C_ADDR, I2C_Direction_Transmitter);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));

    while(len--)
    {
        I2C_SendData(I2C1, *data++);
        while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
    }

    I2C_GenerateSTOP(I2C1, ENABLE);
}

SSD1306的初始化函数和数据更新函数：

#define SSD1306_WIDTH 128
#define SSD1306_HEIGHT 64
#define SSD1306_BUFFER_SIZE (SSD1306_WIDTH*SSD1306_HEIGHT/8)

uint8_t SSD1306_Buffer[SSD1306_BUFFER_SIZE];

void SSD1306_Init(void)
{
    SSD1306_I2C_Init();

    // Turn display off
    SSD1306_DisplayOff();

    // Set the clock to a high value for faster data transfer
    SSD1306_I2C_WriteReg(0x0F, 0x80);

    // Set multiplex ratio to default value (63)
    SSD1306_I2C_WriteReg(0xA8, 0x3F);

    // Set the display offset to 0
    SSD1306_I2C_WriteReg(0xD3, 0x00);

    // Display start line is 0
    SSD1306_I2C_WriteReg(0x40, 0x00);

    // Set segment remap to inverted
    SSD1306_I2C_WriteReg(0xA1, 0xC0);

    // Set COM output scan direction to inverted
    SSD1306_I2C_WriteReg(0xC8, 0xC0);

    // Disable display offset shift
    SSD1306_I2C_WriteReg(0xD7, 0x9F);

    // Set display clock divide ratio/oscillator frequency to default value (8/0xF0)
    SSD1306_I2C_WriteReg(0xD5, 0xF0);

    // Enable charge pump regulator
    SSD1306_I2C_WriteReg(0x8D, 0x14);

    // Set memory addressing mode
    // Set the display to normal mode (not inverted)
SSD1306_I2C_WriteReg(0xA6, 0xA6);

// Set the contrast to a default value of 127
SSD1306_I2C_WriteReg(0x81, 0x7F);

// Turn the display back on
SSD1306_DisplayOn();

// Clear the display buffer
SSD1306_ClearBuffer();

// Update the display with the cleared buffer
SSD1306_UpdateDisplay();
}

void SSD1306_UpdateDisplay(void) { uint8_t column, page;
}for(page=0; page<8; page++)
{
    SSD1306_I2C_WriteReg(0xB0+page, 0x00);
    SSD1306_I2C_WriteReg(0x10, 0x00);
    SSD1306_I2C_WriteReg(0x00, 0x00);

    for(column=0; column<SSD1306_WIDTH; column++)
    {
        SSD1306_I2C_WriteArray(&SSD1306_Buffer[column + page*SSD1306_WIDTH], 1);
    }
}
}
void SSD1306_ClearBuffer(void) { memset(SSD1306_Buffer, 0x00, sizeof(SSD1306_Buffer)); }

void SSD1306_SetPixel(uint8_t x, uint8_t y, uint8_t color) { if(x >= SSD1306_WIDTH || y >= SSD1306_HEIGHT) { return; }
}if(color)
{
    SSD1306_Buffer[x + (y/8)*SSD1306_WIDTH] |= (1 << (y%8));
}
else
{
    SSD1306_Buffer[x + (y/8)*SSD1306_WIDTH] &= ~(1 << (y%8));
}
}