芯耀
1125
一、項(xiàng)目介紹
當(dāng)前文章介紹基于STM32設(shè)計的人體健康檢測儀。設(shè)備采用STM32系列MCU作為主控芯片，配備血氧濃度傳感器（使用MAX30102血氧濃度檢測傳感器）、OLED屏幕和電池供電等外設(shè)模塊。設(shè)備可以廣泛應(yīng)用于醫(yī)療、健康等領(lǐng)域?？梢詭椭t(yī)生和病人更好地了解病情變化，提高治療效果和生活質(zhì)量。設(shè)備也可以用于健康管理、運(yùn)動監(jiān)測等場景，幫助用戶了解自己的身體狀況，保持健康的生活方式。
在項(xiàng)目中，使用了KEIL作為開發(fā)平臺和工具，通過血氧模塊采集人體的心跳和血氧濃度參數(shù)，并通過OLED屏幕顯示現(xiàn)在的心跳和血氧濃度。同時，通過指標(biāo)分析，提供采集到的數(shù)據(jù)與正常指標(biāo)比對，分析被檢測人員的健康狀態(tài)。采集的數(shù)據(jù)可通過藍(lán)牙或者WIFI傳遞給手機(jī)APP進(jìn)行處理，方便用戶隨時了解自己的身體狀況。
本設(shè)計采用STM32為主控芯片，搭配血氧濃度傳感器和OLED屏幕，實(shí)現(xiàn)了人體健康數(shù)據(jù)的采集和展示，并對采集到的數(shù)據(jù)進(jìn)行分析，判斷被檢測人員的健康狀態(tài)。同時，設(shè)計使用藍(lán)牙或WiFi將采集到的數(shù)據(jù)傳遞給手機(jī)APP進(jìn)行處理。
二、項(xiàng)目設(shè)計思路
2.1 硬件設(shè)計
（1）主控芯片：STM32系列MCU，負(fù)責(zé)驅(qū)動其他外設(shè)模塊；
（2）血氧濃度傳感器：使用MAX30102血氧濃度檢測傳感器，用于采集人體的心跳和血氧濃度參數(shù)；
（3）OLED屏：用于顯示現(xiàn)在的心跳和血氧濃度；
2.2 軟件設(shè)計
(1) 通過血氧模塊采集人體的心跳和血氧濃度參數(shù)；
(2) 通過OLED屏顯示現(xiàn)在的心跳和血氧濃度；
(3) 對采集到的數(shù)據(jù)進(jìn)行指標(biāo)分析，將采集到的數(shù)據(jù)與正常指標(biāo)比對，分析被檢測人員的健康狀態(tài)；
(4) 采集的數(shù)據(jù)可通過藍(lán)牙或WiFi傳遞給手機(jī)APP進(jìn)行處理。
2.3 技術(shù)實(shí)現(xiàn)
（1）設(shè)計采用AD8232心電圖（ECG）模塊和MAX30102血氧模塊采集心跳和血氧濃度參數(shù)，并通過I2C接口連接主控芯片STM32。
（2）OLED屏使用I2C接口與主控芯片STM32連接。
（3）采集到的數(shù)據(jù)通過算法進(jìn)行指標(biāo)分析，將采集到的數(shù)據(jù)與正常指標(biāo)比對，判斷被檢測人員的健康狀態(tài)。
（4）設(shè)備通過藍(lán)牙或WiFi將采集到的數(shù)據(jù)傳遞給手機(jī)APP進(jìn)行處理。
三、代碼設(shè)計
3.1 MAX30102血氧模塊代碼
I2C協(xié)議代碼：
#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的初始化函數(shù)和數(shù)據(jù)獲取函數(shù)：
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;
}
數(shù)據(jù)處理函數(shù)：
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顯示屏驅(qū)動代碼
I2C協(xié)議代碼：
#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的初始化函數(shù)和數(shù)據(jù)更新函數(shù)：
#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));
}
}
四、總結(jié)
本設(shè)計采用STM32為主控芯片，配合血氧濃度傳感器和OLED屏幕，實(shí)現(xiàn)了人體健康數(shù)據(jù)的采集和展示，并通過算法對采集到的數(shù)據(jù)進(jìn)行分析，判斷被檢測人員的健康狀態(tài)。同時，設(shè)計使用藍(lán)牙或WiFi將采集到的數(shù)據(jù)傳遞給手機(jī)APP進(jìn)行處理。設(shè)計基本滿足了人體健康檢測儀的技術(shù)要求和環(huán)境要求。
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