si7021.py 文件源码

def getHumidity():
    bus = smbus.SMBus(1)
    bus.write_byte(0x40, 0xF5)

    time.sleep(0.3)

# SI7021 address, 0x40(64)
# Read data back, 2 bytes, Humidity MSB first
    data0 = bus.read_byte(0x40)
    data1 = bus.read_byte(0x40)

# Convert the data
    humidity = ((data0 * 256 + data1) * 125 / 65536.0) - 6
    print ("Relative Humidity is : %.2f %%" %humidity)
    return humidity