STM32F103读取BME280

BME280是一款数字式温湿度气压传感器，可以通过I2C或SPI接口与STM32F103进行通信。以下是使用I2C接口读取BME280的示例代码：

#include "stm32f10x.h"
#include "i2c.h"

#define BME280_ADDRESS 0xEE

uint8_t bme280_read_byte(uint8_t reg)
{
    uint8_t data;
    I2C_Start();
    I2C_SendByte(BME280_ADDRESS << 1);
    I2C_WaitAck();
    I2C_SendByte(reg);
    I2C_WaitAck();
    I2C_Start();
    I2C_SendByte((BME280_ADDRESS << 1) | 0x01);
    I2C_WaitAck();
    data = I2C_ReceiveByte();
    I2C_Stop();
    return data;
}

int16_t bme280_read_short(uint8_t reg)
{
    uint8_t data[2];
    int16_t value;
    I2C_Start();
    I2C_SendByte(BME280_ADDRESS << 1);
    I2C_WaitAck();
    I2C_SendByte(reg);
    I2C_WaitAck();
    I2C_Start();
    I2C_SendByte((BME280_ADDRESS << 1) | 0x01);
    I2C_WaitAck();
    data[0] = I2C_ReceiveByte();
    I2C_Ack();
    data[1] = I2C_ReceiveByte();
    I2C_Nack();
    I2C_Stop();
    value = (int16_t)((data[1] << 8) | data[0]);
    return value;
}

void bme280_init(void)
{
    // Set BME280 to normal mode with 16x oversampling for temperature,
    // 16x oversampling for humidity, and 16x oversampling for pressure
    bme280_write_byte(0xF2, 0x01);
    bme280_write_byte(0xF4, 0x27);
}

void bme280_read_data(int32_t *temperature, uint32_t *humidity, uint32_t *pressure)
{
    int32_t var1, var2, t_fine;
    int32_t adc_T, adc_H, adc_P;

    adc_T = bme280_read_short(0xFA);
    adc_H = (uint32_t)bme280_read_short(0xFD);
    adc_P = (uint32_t)bme280_read_short(0xF7);

    var1 = ((((adc_T >> 3) - ((int32_t)bme280_read_short(0x88) << 1))) *
            ((int32_t)bme280_read_short(0x8A))) >> 12;
    var2 = ((((adc_T >> 4) - ((int32_t)bme280_read_short(0x88))) *
             ((adc_T >> 4) - ((int32_t)bme280_read_short(0x88)))) >> 12) *
           ((int32_t)bme280_read_short(0x89)) >>
           10;
    t_fine = var1 + var2;

    *temperature = (t_fine * 5 + 128) >> 8;
    *humidity = (((adc_H >> 4) - ((int32_t)bme280_read_byte(0xA1) << 4) -
                  (((int32_t)bme280_read_byte(0xE1)) >> 4) + 16384) >>
                 15) *
                (((((((t_fine)-76800) * (int32_t)bme280_read_byte(0xE3))) >> 7) +
                   ((int32_t)bme280_read_byte(0xE4) << 16)) >>
                  2) +
                 1) >>
                16;
    *pressure = (((((adc_P >> 3) - ((int32_t)bme280_read_short(0x8E) << 1))) *
                   ((int32_t)bme280_read_short(0x8F))) >>
                  12) +
                 (((((adc_P >> 2) - ((int32_t)bme280_read_short(0x8E))) *
                    ((adc_P >> 2) - ((int32_t)bme280_read_short(0x8E)))) >>
                   13) *
                  ((int32_t)bme280_read_short(0x90))) >>
                 16;
}

int main(void)
{
    int32_t temperature;
    uint32_t humidity, pressure;

    I2C_Init();
    bme280_init();

    while (1)
    {
        bme280_read_data(&temperature, &humidity, &pressure);
        // do something with the data
    }
}

以上代码假设已经在STM32F103上实现了I2C接口的读写函数。在main函数中，首先调用bme280_init函数初始化BME280传感器，然后在循环中调用bme280_read_data函数读取温湿度气压数据，最后可以根据需要对数据进行处理。