rfid_com.py

import time
import board
import busio
from digitalio import DigitalInOut
from spotify_api import device_card_uid, learn_card_uid
from adafruit_pn532.adafruit_pn532 import MIFARE_CMD_AUTH_B, MIFARE_CMD_AUTH_A
from adafruit_pn532.spi import PN532_SPI

# RFID-Setup
spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
cs_pin = DigitalInOut(board.D5)
pn532 = PN532_SPI(spi, cs_pin, debug=False)
ic, ver, rev, support = pn532.firmware_version
print("Found PN532 with firmware version: {0}.{1}".format(ver, rev))
# pn532.SAM_configuration()
pn532.listen_for_passive_target()


def wait_for_uid():
    uid = pn532.read_passive_target(timeout=10)
    while uid is None:
        uid = pn532.read_passive_target(timeout=10)
        print(".", end="")
    str_uid = "".join(format(x, "0x") for x in uid)
    return uid, str_uid


def check_once(timeout):
    uid = pn532.read_passive_target(timeout=timeout)
    if uid is not None:
        str_uid = "".join(format(x, "0x") for x in uid)
        return uid, str_uid
    return -1, -1


def RFID_read(block):
    data = pn532.ntag2xx_read_block(block)
    if data is None:
        return -1
    return data


def read_uri(uid):
    data_arrays = []
    str_uid = ""
    # while(data_arrays[-1] != bytearray(4)):
    for i in range(10, 31):
        array = RFID_read(i)
        if array == bytearray(4):
            str_uid = "".join([x.decode("utf-8").strip("\x00") for x in data_arrays])
            break
        elif array == -1:
            print("Card reading Error!")
            return -1
        else:
            data_arrays.append(array)

    if str_uid == "":
        print("Card empty.")
        return -1
    else:
        return str_uid


def write_block(block, data):
    if pn532.ntag2xx_write_block(block, data) is False:
        return -1


def write_uri(uri):
    # preparing uri into byte arrays
    parts = [uri[i : i + 4] for i in range(0, len(uri), 4)]
    print("Number of Blocks: {}".format(len(parts)))
    # making bytearrays with 16bytes of size, no matter what
    data_arrays = [bytearray(i, "utf-8") + bytearray(4 - len(i)) for i in parts]

    for i in range(len(data_arrays)):
        if write_block(i + 10, data_arrays[i]) == -1:
            return -1

    # formatting 8 Blocks after Data so no old data gets mixed up
    for i in range(len(data_arrays), len(data_arrays) + 9):
        if write_block(i + 10, bytearray(4)) == -1:
            return -1


if __name__ == "__main__":

    while 1:
        print("Scan and hold the card now.")
        uid, str_uid = wait_for_uid()
        print("UID-Found:{}".format(str_uid))
        uri = read_uri(uid)
        if uri == "":
            print("Card empty.")
        else:
            print(uri)
        time.sleep(5)

    """
    while(1):
        uid = pn532.read_passive_target(timeout=0.5)
        if uid is None:
            continue
        else:
            print(uid)
    """


""" Only used for testing
def RFID_read_test(uidlenght=4):
    try:
        import random
    except ImportError:
        pass

    if uidlenght == 0:
        uid = None
    else:
        uid = bytearray([random.randint(0, 255) for _ in range(uidlenght)])
    return uid
"""