max31855.py 文件源码

def __init__(self, cs_pin, clock_pin, data_pin, units = "c", board = GPIO.BCM):
        '''Initialize Soft (Bitbang) SPI bus

        Parameters:
        - cs_pin:    Chip Select (CS) / Slave Select (SS) pin (Any GPIO)  
        - clock_pin: Clock (SCLK / SCK) pin (Any GPIO)
        - data_pin:  Data input (SO / MOSI) pin (Any GPIO)
        - units:     (optional) unit of measurement to return. ("c" (default) | "k" | "f")
        - board:     (optional) pin numbering method as per RPi.GPIO library (GPIO.BCM (default) | GPIO.BOARD)

        '''
        self.cs_pin = cs_pin
        self.clock_pin = clock_pin
        self.data_pin = data_pin
        self.units = units
        self.data = None
        self.board = board

        # Initialize needed GPIO
        GPIO.setmode(self.board)
        GPIO.setup(self.cs_pin, GPIO.OUT)
        GPIO.setup(self.clock_pin, GPIO.OUT)
        GPIO.setup(self.data_pin, GPIO.IN)

        # Pull chip select high to make chip inactive
        GPIO.output(self.cs_pin, GPIO.HIGH)