Python 3 script to demonstrate writing custom data to Ultimaker filament NFC tag

write_spool_nfc.py

# -*- coding: utf-8 -*-
# https://github.com/BrianHVB/intro-to-smartcard-development#heading--python-example-1
#
# required packages: pyscard
#
from smartcard.Exceptions import NoCardException
from smartcard.System import *
from smartcard import util
from ums5 import MyFilamentSpool, decode
import uuid
from binascii import hexlify


class MustBeEvenException(Exception):
    pass


def cmd_read_page(start, count=4):
    return [0xff, 0xb0, (start >> 8) & 0xff, start & 0xff, count & 0xff]


def cmd_write_page(start, data):
    if isinstance(data, bytes):
        data = list(data)
    count = len(data)
    return [0xff, 0xd6, (start >> 8) & 0xff, start & 0xff, count & 0xff] + data


def main():
    # get and print a list of readers attached to the system
    sc_readers = readers()
    print(sc_readers)

    # create a connection to the first reader
    first_reader = sc_readers[0]
    connection = first_reader.createConnection()

    # get ready for a command
    get_uid = util.toBytes("FF CA 00 00 00")

    try:
        # send the command and capture the response data and status
        connection.connect()
        uid_data, sw1, sw2 = connection.transmit(get_uid)

        # print the response
        uid = util.toHexString(uid_data)
        status = util.toHexString([sw1, sw2])
        serial = hexlify(bytes(uid_data)).decode('latin').upper()

        print("UID = {}\tstatus = {}\tdata={}".format(uid, status, uid_data))

        carbon = MyFilamentSpool(uuid.UUID("4debf055-6eed-4795-b4c4-4643fba8ea53"), 800000, serial)
        decode(carbon.data())

        tag_data = carbon.data()
        for i in range(0, len(tag_data), 4):
            page = i//4 + 4
            data = list(tag_data[i:i+4])  # no padding required, length of encoded data is already a multiple of 4 
            print("[{:02x}] = {}".format(page, util.toHexString(data)))
            # print("[{:02x}] = {}\tstatus = {}".format(page, util.toHexString(data), util.toHexString([sw1, sw2])))
            recv, sw1, sw2 = connection.transmit(cmd_write_page(page, data))
            print("[{:02x}] = {}\trecv = {}\tstatus = {}".format(page, util.toHexString(data),
                                                                 util.toHexString(recv),
                                                                 util.toHexString([sw1, sw2])))
        decode(bytes(tag_data))

    except NoCardException:
        print("ERROR: Card not present")


if __name__ == '__main__':
    main()