Wiegand protocol reader for micropython

This library is essentially the Wiegand class, which allows the user to set callbacks based on receiving a card number from a wiegand-protocol reader.

Example usage:

    from wiegand import Wiegand
    VALID_FACILITY_CODES = [ '123']
    VALID_CARDS = [ '12345' ]

    GREEN_LED = Pin(...)
    RED_LED = Pin(...)

    WIEGAND_ZERO = XX  # Pin number here
    WIEGAND_ONE = YY   # Pin number here

    def on_card(card_number, facility_code, cards_read):
	if (card_number in VALID_CARDS) and (facility_code in VALID_FACILITY_CODES):
	    GREEN_LED.high()
	    RED_LED.low()
	else:
	    RED_LED.high()
	    GREEN_LED.low()
    
    
    Wiegand(WIEGAND_ZERO, WIEGAND_ONE, on_card)