spi驱动bmp280

以下是基于树莓派的SPI驱动BMP280的代码示例，你可以参考一下：

import spidev
import time

class BMP280:
    def __init__(self, bus, device):
        self.spi = spidev.SpiDev()
        self.spi.open(bus, device)
        self.spi.max_speed_hz = 1000000  # 设置SPI通信速度为1MHz
        self.spi.mode = 3               # 设置SPI通信模式为模式3
        self.calibration_data = self._read_calibration_data()
        self.temperature = 0
        self.pressure = 0

    def _read_calibration_data(self):
        # 读取BMP280的校准数据
        calibration_data = []
        for address in range(0x88, 0x88+24, 2):
            data = self.spi.xfer([address, 0])
            calibration_data.append((data[1] << 8) | data[0])
        calibration_data.append((self.spi.xfer([0xA1, 0])[1] << 8) | self.spi.xfer([0xE1, 0])[1])
        return calibration_data

    def _read_adc(self, address):
        # 读取BMP280的温度或压力原始数据
        data = self.spi.xfer([address, 0, 0, 0])
        adc = (data[1] << 16) | (data[2] << 8) | data[3]
        adc >>= 4
        return adc

    def _compensate_temperature(self, adc_temp):
        # 根据校准数据计算温度值
        var1 = (adc_temp / 16384.0 - self.calibration_data[0] / 1024.0) * self.calibration_data[1]
        var2 = ((adc_temp / 131072.0 - self.calibration_data[0] / 8192.0) * (adc_temp / 131072.0 - self.calibration_data[0] / 8192.0)) * self.calibration_data[2]
        return var1 + var2

    def _compensate_pressure(self, adc_press):
        # 根据校准数据计算压力值
        var1 = (self.temperature / 2.0 - self.calibration_data[5]) * self.calibration_data[6]
        var2 = var1 * var1 / 2048.0
        var2 = var2 * self.calibration_data[4] / 16384.0
        var3 = var1 * self.calibration_data[3] / 1024.0
        var4 = var1 * var1 / 4096.0
        var4 = self.calibration_data[2] * var4 / 16.0
        var5 = 8192.0 + var3 + var4
        var6 = var5 / 2.0 / self.pressure
        var7 = var6 * adc_press
        var8 = self.calibration_data[1] * var6 / 8192.0
        pressure = var7 + var8
        return pressure

    def read_data(self):
        adc_temp = self._read_adc(0xFA)
        adc_press = self._read_adc(0xF7)
        self.temperature = self._compensate_temperature(adc_temp)
        self.pressure = self._compensate_pressure(adc_press)

if __name__ == '__main__':
    bmp280 = BMP280(0, 0)  # 初始化BMP280对象
    while True:
        bmp280.read_data()  # 读取温度和压力数据
        print('Temperature: {} C'.format(round(bmp280.temperature, 2)))
        print('Pressure: {} Pa'.format(round(bmp280.pressure, 2)))
        time.sleep(1)

需要注意的是，BMP280使用SPI接口与树莓派进行通信，需要先在树莓派上开启SPI接口。具体步骤请参考树莓派官方文档。