The MFRC522 is a popular RFID module that supports contactless communication using the 13.56 MHz frequency. It can read and write data to RFID cards or tags, making it ideal for projects that require identification or access control. This repository provides a library and example code to interact with the MFRC522 module using various microcontroller platforms.
Sectors and Blocks refer to the organization and structure of memory on an RFID tag or card.
The memory of card is divided into 16 sectors (for classic MIFARE 1k). Each sector contains 4 blocks and each block can hold upto 16 bytes of data.
So a classic MIFARE 1k has 16 sectors, 64 blocks (16 sectors x 4 blocks) and can hold upto 1024 bytes (64 blocks x 16 bytes) in total.
Not Every blocks are writeable, the first block of the first sector and the last block of every sectors are not writeable.
The first block of first sector typically holds the manufaturer's details (like manufacturer's identification number (MID) and the application identifier (AID). The MID is a unique number that identifies the manufacturer of the card. The AID is a unique number that identifies the application that is stored on the card.). The last block of every sector is called a trailer block, the trailer block contains information about the sector, such as the sector number, the number of blocks in the sector, and the checksum. The checksum is used to verify the integrity of the data in the sector. If you ever write to a trailer block then the entire sector will be unwritable.
Sectors | Block Number |
---|---|
0 | 0, 1, 2, 3 |
1 | 4, 5, 6, 7 |
2 | 8, 9, 10, 11 |
3 | 12, 13, 14, 15 |
4 | 16, 17, 18, 19 |
5 | 20, 21, 22, 23 |
6 | 24, 25, 26, 27 |
7 | 28, 29, 30, 31 |
8 | 32, 33, 34, 35 |
9 | 36, 37, 38, 39 |
10 | 40, 41, 42, 43 |
11 | 44, 45, 46, 47 |
12 | 48, 49, 50, 51 |
13 | 52, 53, 54, 55 |
14 | 56, 57, 58, 59 |
15 | 60, 61, 62, 63 |
Manfacturer's details is stored in block number 0 and
Trailer blocks are 3, 7, 11, etc,.
( Tips: It's better to not store any data in the first sector. Start from the first sector )
Note: Different cards have diiferent number of sectors and blocks. For example, Classic MIFARE 4k has 40 Sectors. It's better to check the datasheet for the RFID tag/card you use before writing data to it.
pip install mfrc522-python
pip install git+https://github.com/1AdityaX/mfrc522-python
RF522 Module | Raspberry Pi |
---|---|
SDA | Pin 24 / GPIO8 (CE0) |
SCK | Pin 23 / GPIO11 (SCKL) |
MOSI | Pin 19 / GPIO10 (MOSI) |
MISO | Pin 21 / GPIO9 (MISO) |
IRQ | – |
GND | GND |
RST | Pin 22 / GPIO25 |
3.3V | 3.3V |
MFRC522
classMFRC522
from mfrc522
module.
from mfrc522 import MFRC522
reader = MFRC522()
2. Request communication with a PICC *(Proximity Integrated Circuit Card A.K.A rfid card)* and check if the communication is established.
```py
status = None
while status != reader.MI_OK:
(status, TagType) = reader.Request(reader.PICC_REQIDL)
if status == reader.MI_OK:
print("Connection Success!")
(status, uid) = reader.Anticoll()
if status == reader.MI_OK:
print(uid)
reader.SelectTag(uid)
trailer_block = 11
#This is the default key for MIFARE Cards
key = [0xFF, 0xFF, 0xFF , 0xFF, 0xFF, 0xFF]
status = reader.Authenticate(
reader.PICC_AUTHENT1A, trailer_block , key, uid)
To read
block_nums = [8, 9, 10]
data = []
for block_num in block_nums:
block_data = reader.ReadTag(block_num)
if block_data:
data += block_data
if data:
print(''.join(chr(i) for i in data))
To write
block_nums = [8, 9, 10]
text = "Hello, World"
data = bytearray()
data.extend(bytearray(text.ljust( len(block_addrs) * 16).encode('ascii')))
i = 0
for block_num in block_addrs:
reader.WriteTag(block_num, data[(i*16):(i+1)*16])
i += 1
reader.StopAuth()
SimpleMFRC522
classSimpleMFRC522
from mfrc522
module
from mfrc522 import SimpleMFRC522
reader = SimpleMFRC522()
2. Use `read()` to read and `write()` to write
**To read**
```py
id, text = reader.read()
print(f"ID: {id}")
print(f"Text: {text}")
To write
text = "hello_world"
id, text_written = reader.write(text)
print(f"ID: {id}")
print(f"Text Written: {text_written}")
mfrc522.SimpleMFRC522()
Methods__init__()
Initializes a SimpleMFRC522
instance. It sets up the MFRC522 module, defines the default authentication key, sets the trailer block number to 11, and initializes the BasicMFRC522 module.
read()
Reads data from the RFID tag.
read_id()
Reads the tag ID from the RFID tag.
write(text)
Writes the given text to an RFID tag.
text
(str): A string to be written to the RFID tag.BasicMFRC522
classBasicMFRC522
from mfrc522
module
from mfrc522 import BasicMFRC522
reader = BasicMFRC522()
2. Use any methods.
### `mfrc522.BasicMFRC522` Methods
#### `__init__(KEY=[0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF])`
Initializes a `BasicMFRC522` instance.
- Args:
- `KEY` (list): The authentication key used for reading and writing data. The default key is `[0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF]`.
#### `read_sector(trailer_block=11)`
Reads data from a sector of the RFID tag.
- Args:
- `trailer_block` (int): The block number of the sector trailer.
- Returns:
- `tuple`: A tuple containing the tag ID (as an integer) and the data read (as a string).
#### `read_sectors(trailer_blocks=[11])`
Reds data from multiple sectors of the RFID tag.
- Args:
- `trailer_blocks` (list): The list of block numbers of the sector trailers.
- Returns:
- `tuple`: A tuple containing the tag ID (as an integer) and the concatenated data read from all sectors (as a string).
#### `read_id()`
Reads the tag ID from the RFID tag.
- Returns:
- `int`: The tag ID as an integer.
#### `read_id_no_block()`
Attempts to read the tag ID from the RFID tag without blocking.
- Returns:
- `int`: The tag ID as an integer, or `None` if the operation fails.
#### `read_no_block(trailer_block)`
Attempts to read data from the RFID tag without blocking.
- Args:
- `trailer_block` (int): The block number of the sector trailer.
- `block_addr` (tuple): The block numbers of the data blocks to read.
- Returns:
- `tuple`: A tuple containing the tag ID (as an integer) and the data read (as a string), or `(None, None)` if the operation fails.
#### `write_sector(text, trailer_block=11)`
Writes data to a sector of the RFID tag.
- Args:
- `text` (str): The data to write.
- `trailer_block` (int): The block number of the sector trailer.
- Returns:
- `tuple`: A tuple containing the tag ID (as an integer) and the data written (as a string).
#### `write_sectors(text, trailer_blocks=[11])`
Writes data to multiple sectors of the RFID tag.
- Args:
- `text` (str): The data to write.
- `trailer_blocks` (list): The list of block numbers of the sector trailers.
- Returns:
- `tuple`: A tuple containing the tag ID (as an integer) and the concatenated data written to all sectors (as a string).
#### `write_no_block(text, trailer_block)`
Attempts to write data to the RFID tag without blocking.
- Args:
- `text` (str): The data to write.
- `trailer_block` (int): The block number of the sector trailer.
- `block_addr` (tuple): The block numbers.
#### `clear_sector(trailer_block=11)`
Clears a sector of the RFID tag by writing empty data to all blocks.
- Args:
- `trailer_block` (int): The block number of the sector trailer.
- Returns:
- `tuple`: A tuple containing the tag ID (as an integer) and the cleared data (as an empty string).
#### `clear_sectors(trailer_blocks=[11])`
Clears multiple sectors of the RFID tag by writing empty data to all blocks.
- Args:
- `trailer_blocks` (list): The list of block numbers of the sector trailers.
- Returns:
- `tuple`: A tuple containing the tag ID (as an integer) and the concatenated cleared data (as an empty string).
#### `clear_no_block(trailer_block)`
Attempts to clear a sector of the RFID tag without blocking.
- Args:
- `trailer_block` (int): The block number of the sector trailer.
- `block_addr` (tuple): The block numbers of the data blocks to clear.
- Returns:
- `tuple`: A tuple containing the tag ID (as an integer) and the cleared data (as an empty string), or `(None, None)` if the operation fails.
**Note: Clearing a sector will permanently erase the data stored in the blocks of that sector. Use with caution as this operation cannot be undone.**
## Example Code
### Using `MFRC522` class
**read.py**
To read a particular sector and convert the bytes to plain string/text.
```py
from mfrc522 import MFRC522
reader = MFRC522()
def read(trailer_block, key, block_addrs):
(status, TagType) = reader.Request(reader.PICC_REQIDL)
if status != reader.MI_OK:
return None, None
(status, uid) = reader.Anticoll()
if status != reader.MI_OK:
return None, None
id = uid
reader.SelectTag(uid)
status = reader.Authenticate(
reader.PICC_AUTHENT1A, trailer_block , key, uid)
data = []
text_read = ''
if status == reader.MI_OK:
for block_num in block_addrs:
block = reader.ReadTag(block_num)
if block:
data += block
if data:
text_read = ''.join(chr(i) for i in data)
reader.StopAuth()
return id, text_read
trailer_block = 11
key = [0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF]
block_addrs = [8,9,10]
id, text = read(trailer_block, key, block_addrs)
while not id:
id, text = read(trailer_block, key, block_addrs)
print(id)
print(text)
write.py
To write a particular sector.
from mfrc522 import MFRC522
reader = MFRC522()
def write(trailer_block, key, block_addrs, text):
(status, TagType) = reader.Request(reader.PICC_REQIDL)
if status != reader.MI_OK:
return None, None
(status, uid) = reader.Anticoll()
if status != reader.MI_OK:
return None, None
reader.SelectTag(uid)
status = reader.Authenticate(
reader.PICC_AUTHENT1A, trailer_block, key, uid)
reader.ReadTag(trailer_block)
if status == reader.MI_OK:
data = bytearray()
data.extend(bytearray(text.ljust(
len(block_addrs) * 16).encode('ascii')))
i = 0
for block_num in block_addrs:
reader.WriteTag(block_num, data[(i*16):(i+1)*16])
i += 1
reader.StopAuth()
return uid, text[0:(len(block_addrs) * 16)]
trailer_block = 11
block_addrs = [8, 9, 10]
key = [0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF]
text = "some random text"
uid, text_in = write(trailer_block, key, block_addrs, text)
while not uid:
uid, text_in = write(trailer_block, key, block_addrs, text)
print(uid)
print(text_in)
SimpleMFRC522
classread.py
from mfrc522 import SimpleMFRC522
reader = SimpleMFRC522()
id, text = reader.read()
print(f"ID: {id}")
print(f"Text: {text}")
write.py
from mfrc522 import SimpleMFRC522
writer = SimpleMFRC522()
text = "Hello, world"
id, text_written = writer.write(text)
print(f"ID: {id}")
print(f"Text Written: {text_written}")
BasicMFRC522
classread_sector.py To read a particular sector
from mfrc522 import BasicMFRC522
reader = BasicMFRC522()
sector = 15
id, text = reader.read_sector(sector)
print(f"ID: {id}")
print(f"Text: {text}")
read_sectors.py To read multiple sectors
from mfrc522 import BasicMFRC522
reader = BasicMFRC522()
sectors = [11, 15]
id, text = reader.read_sectors(sectors)
print(f"ID: {id}")
print(f"Text: {text}")
write_sector.py To write a particular sector
from mfrc522 import BasicMFRC522
writer = BasicMFRC522()
sector = 15
text = "Example to use write_sector method"
id, text_written = writer.write_sector(text, sector)
print(f"ID: {id}")
print(f"Text Written: {text_written}")
write_sectors.py To write multiple sectors
from mfrc522 import BasicMFRC522
writer = BasicMFRC522()
sector = [11, 15]
text = "Example to use write_sector method"
id, text_written = writer.write_sectors(text, sector)
print(f"ID: {id}")
print(f"Text Written: {text_written}")
clear_sector.py To clear data written in a sector
from mfrc522 import BasicMFRC522
writer = BasicMFRC522()
sector = 11
id = writer.clear_sector(sector)
print("Cleared")
clear_sectors.py To clear data written in multiple sectors
from mfrc522 import BasicMFRC522
writer = BasicMFRC522()
sectors = [11, 15]
id = writer.clear_sectors(sectors)
print("Cleared")
Contributions to the mfrc522-python
library are welcome. To contribute, follow these steps:
That's it! By submitting a pull request, you can contribute your changes to the mfrc522-python
library.
Provide a clear description of your changes in the pull request.
If you have any questions or need further assistance, feel free to open an issue.
This project is licensed under the GNU General Public License (GPL) version 3.0. You can find the full text of the license in the LICENSE file.