def write():
status = False
text = request.json.get('text')
tag_id = None
tag_text = None
if text is not None:
status = True
rfid = RFID()
tag_id, tag_text = rfid.write(text=text)
return {
'id': str(tag_id),
'text': tag_text.strip() if tag_text else tag_text,
'status': status
}
def write(self, data):
"""
Write a 16-byte string of data to the tag
"""
if len(data) != 16:
logger.debug(f"Illegal data length, expected 16, got {len(data)}")
return False
with self.mutex:
rdr = RFID()
success = False
# check for presence of tag
err, _ = rdr.request()
if not err:
logger.debug("RFIDHandler write: Tag is present")
# tag is present, get UID
err, uid = rdr.anticoll()
if not err:
logger.debug("RFIDHandler write: Read UID: " + str(uid))
# write data: RFID lib writes 16 bytes at a time, but for NTAG213
# only the first four are actually written
err = False
for i in range(4):
page = self.page + i
page_data = [ord(c)
for c in data[4 * i:4 * i + 4]] + [0] * 12
# read data once (necessary for successful writing?)
err_read, _ = rdr.read(page)
if err:
logger.debug(
"Error signaled on reading page {:d} before writing"
.format(page))
# write data
err |= rdr.write(page, page_data)
if err:
logger.debug(
f'Error signaled on writing page {page:d} with data {page_data:s}'
)
if not err:
logger.debug(
"RFIDHandler write: successfully wrote tag data")
success = True
else:
logger.debug(
"RFIDHandler write: Error returned from write()")
else:
logger.debug(
"RFIDHandler write: Error returned from anticoll()")
# clean up
rdr.cleanup()
return success