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Pylint, doc, and better raspi support

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Your Name 2018-08-25 20:39:16 +00:00
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4
README.rst
View file

@ -13,7 +13,7 @@ Introduction
:target: https://travis-ci.org/adafruit/adafruit_CircuitPython_PN532
:alt: Build Status
.. todo:: Describe what the library does.
CircuitPython driver for the `PN532 NFC/RFID Breakout <https://www.adafruit.com/product/364>`_ and `PN532 NFC/RFID Shield <https://www.adafruit.com/product/789>`_
Dependencies
=============
@ -29,7 +29,7 @@ This is easily achieved by downloading
Usage Example
=============
.. todo:: Add a quick, simple example. It and other examples should live in the examples folder and be included in docs/examples.rst.
Check examples/pn532_simpletest.py for usage example
Contributing
============

155
adafruit_pn532.py
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@ -23,7 +23,7 @@
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
"""
`adafruit_PN532`
``adafruit_pn532``
====================================================
This module will let you communicate with a PN532 RFID/NFC shield or breakout
@ -43,13 +43,12 @@ Implementation Notes
* Adafruit CircuitPython firmware for the supported boards:
https://github.com/adafruit/circuitpython/releases
* Adafruit's Bus Device library: https://github.com/adafruit/Adafruit_CircuitPython_BusDevice
* Adafruit's Bus Device library: https://github.com/adafruit/Adafruit_CircuitPython_BusDevice
"""
import time
from digitalio import DigitalInOut, Direction
from digitalio import Direction
import adafruit_bus_device.i2c_device as i2c_device
import adafruit_bus_device.spi_device as spi_device
@ -58,7 +57,7 @@ from micropython import const
__version__ = "0.0.0-auto.0"
__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_PN532.git"
# pylint: disable=bad-whitespace
_PREAMBLE = const(0x00)
_STARTCODE1 = const(0x00)
_STARTCODE2 = const(0xFF)
@ -174,8 +173,22 @@ _GPIO_P35 = const(5)
_ACK = b'\x00\x00\xFF\x00\xFF\x00'
_FRAME_START = b'\x00\x00\xFF'
# pylint: enable=bad-whitespace
def _reset(pin):
"""Perform a hardware reset toggle"""
pin.direction = Direction.OUTPUT
pin.value = True
time.sleep(0.1)
pin.value = False
time.sleep(0.5)
pin.value = True
time.sleep(0.1)
def reverse_bit(num):
"""Turn an LSB byte to an MSB byte, and vice versa. Used for SPI as
it is LSB for the PN532, but 99% of SPI implementations are MSB only!"""
result = 0
for _ in range(8):
result <<= 1
@ -197,18 +210,15 @@ class PN532:
"""
self.debug = debug
if reset:
reset.direction = Direction.OUTPUT
reset.value = True
time.sleep(0.1)
reset.value = False
time.sleep(0.1)
reset.value = True
time.sleep(1)
if debug:
print("Resetting")
_reset(reset)
try:
self._wakeup()
self.get_firmware_version() # first time often fails, try 2ce
return
except:
except (BusyError, RuntimeError):
pass
self.get_firmware_version()
@ -216,7 +226,7 @@ class PN532:
# Read raw data from device, not including status bytes:
# Subclasses MUST implement this!
raise NotImplementedError
def _write_data(self, framebytes):
# Write raw bytestring data to device, not including status bytes:
# Subclasses MUST implement this!
@ -227,10 +237,13 @@ class PN532:
# Subclasses MUST implement this!
raise NotImplementedError
def _wakeup(self):
# Send special command to wake up
raise NotImplementedError
def _write_frame(self, data):
"""Write a frame to the PN532 with the specified data bytearray."""
assert data is not None and 0 < len(data) < 255, 'Data must be array of 1 to 255 bytes.'
assert data is not None and 1 < len(data) < 255, 'Data must be array of 1 to 255 bytes.'
# Build frame to send as:
# - Preamble (0x00)
# - Start code (0x00, 0xFF)
@ -266,6 +279,7 @@ class PN532:
response = self._read_data(length+8)
if self.debug:
print('Read frame:', [hex(i) for i in response])
# Swallow all the 0x00 values that preceed 0xFF.
offset = 0
while response[offset] == 0x00:
@ -276,7 +290,7 @@ class PN532:
raise RuntimeError('Response frame preamble does not contain 0x00FF!')
offset += 1
if offset >= len(response):
raise RuntimeError('Response contains no data!')
raise RuntimeError('Response contains no data!')
# Check length & length checksum match.
frame_len = response[offset]
if (frame_len + response[offset+1]) & 0xFF != 0:
@ -288,7 +302,7 @@ class PN532:
# Return frame data.
return response[offset+2:offset+2+frame_len]
def call_function(self, command, response_length=0, params=[], timeout=1):
def call_function(self, command, response_length=0, params=[], timeout=1): # pylint: disable=dangerous-default-value
"""Send specified command to the PN532 and expect up to response_length
bytes back in a response. Note that less than the expected bytes might
be returned! Params can optionally specify an array of bytes to send as
@ -298,12 +312,16 @@ class PN532:
"""
# Build frame data with command and parameters.
data = bytearray(2+len(params))
data[0] = _HOSTTOPN532
data[1] = command & 0xFF
for i in range(len(params)):
data[2+i] = params[i]
data[0] = _HOSTTOPN532
data[1] = command & 0xFF
for i, val in enumerate(params):
data[2+i] = val
# Send frame and wait for response.
self._write_frame(data)
try:
self._write_frame(data)
except OSError:
self._wakeup()
return None
if not self._wait_ready(timeout):
return None
# Verify ACK response and wait to be ready for function response.
@ -328,7 +346,7 @@ class PN532:
raise RuntimeError('Failed to detect the PN532')
return tuple(response)
def SAM_configuration(self):
def SAM_configuration(self): # pylint: disable=invalid-name
"""Configure the PN532 to read MiFare cards."""
# Send SAM configuration command with configuration for:
# - 0x01, normal mode
@ -362,7 +380,7 @@ class PN532:
# Return UID of card.
return response[6:6+response[5]]
def mifare_classic_authenticate_block(self, uid, block_number, key_number, key):
def mifare_classic_authenticate_block(self, uid, block_number, key_number, key): # pylint: disable=invalid-name
"""Authenticate specified block number for a MiFare classic card. Uid
should be a byte array with the UID of the card, block number should be
the block to authenticate, key number should be the key type (like
@ -378,7 +396,7 @@ class PN532:
params[1] = key_number & 0xFF
params[2] = block_number & 0xFF
params[3:3+keylen] = key
params[3+keylen:] = uid
params[3+keylen:] = uid
# Send InDataExchange request and verify response is 0x00.
response = self.call_function(_COMMAND_INDATAEXCHANGE,
params=params,
@ -424,7 +442,8 @@ class PN532:
class PN532_UART(PN532):
"""Driver for the PN532 connected over Serial UART"""
def __init__(self, uart, *, irq=None, reset=None, debug=False):
"""Create an instance of the PN532 class using Serial connection
"""Create an instance of the PN532 class using Serial connection.
Optional IRQ pin (not used), reset pin and debugging output.
"""
self.debug = debug
self._irq = irq
@ -432,10 +451,12 @@ class PN532_UART(PN532):
super().__init__(debug=debug, reset=reset)
def _wakeup(self):
"""Send any special commands/data to wake up PN532"""
#self._write_frame([_HOSTTOPN532, _COMMAND_SAMCONFIGURATION, 0x01])
self.SAM_configuration()
def _wait_ready(self, timeout=1):
"""Wait `timeout` seconds"""
time.sleep(timeout)
return True
@ -446,9 +467,12 @@ class PN532_UART(PN532):
raise BusyError("No data read from PN532")
if self.debug:
print("Reading: ", [hex(i) for i in frame])
else:
time.sleep(0.1)
return frame
def _write_data(self, framebytes):
"""Write a specified count of bytes to the PN532"""
while self._uart.read(1): # this would be a lot nicer if we could query the # of bytes
pass
self._uart.write('\x55\x55\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') # wake up!
@ -456,31 +480,45 @@ class PN532_UART(PN532):
class PN532_I2C(PN532):
"""Driver for the PN532 connected over I2C."""
def __init__(self, i2c, *, irq=None, reset=None, debug=False):
"""Create an instance of the PN532 class using either software SPI (if
the sclk, mosi, and miso pins are specified) or hardware SPI if a
spi parameter is passed. The cs pin must be a digital GPIO pin.
Optionally specify a GPIO controller to override the default that uses
the board's GPIO pins.
def __init__(self, i2c, *, irq=None, reset=None, req=None, debug=False):
"""Create an instance of the PN532 class using I2C. Note that PN532
uses clock stretching. Optional IRQ pin (not used),
reset pin and debugging output.
"""
self.debug = debug
self._irq = irq
self._req = req
if reset:
_reset(reset)
self._i2c = i2c_device.I2CDevice(i2c, _I2C_ADDRESS)
super().__init__(debug=debug, reset=reset)
def _wakeup(self):
def _wakeup(self): # pylint: disable=no-self-use
"""Send any special commands/data to wake up PN532"""
if self._req:
self._req.direction = Direction.OUTPUT
self._req.value = True
time.sleep(0.1)
self._req.value = False
time.sleep(0.1)
self._req.value = True
time.sleep(0.5)
def _wait_ready(self, timeout=1):
"""Poll PN532 if status byte is ready, up to `timeout` seconds"""
status = bytearray(1)
t = time.monotonic()
while (time.monotonic() - t) < timeout:
with self._i2c:
self._i2c.readinto(status)
timestamp = time.monotonic()
while (time.monotonic() - timestamp) < timeout:
try:
with self._i2c:
self._i2c.readinto(status)
except OSError:
self._wakeup()
continue
if status == b'\x01':
return True # No longer busy
else:
time.sleep(0.1) # lets ask again soon!
time.sleep(0.05) # lets ask again soon!
# Timed out!
return False
@ -495,15 +533,19 @@ class PN532_I2C(PN532):
i2c.readinto(frame) # ok get the data, plus statusbyte
if self.debug:
print("Reading: ", [hex(i) for i in frame[1:]])
else:
time.sleep(0.1)
return frame[1:] # don't return the status byte
def _write_data(self, framebytes):
"""Write a specified count of bytes to the PN532"""
with self._i2c as i2c:
i2c.write(framebytes)
class PN532_SPI(PN532):
"""Driver for the PN532 connected over SPI. Pass in a hardware or bitbang SPI device & chip select
digitalInOut pin. Optional IRQ pin (not used), reset pin and debugging output."""
"""Driver for the PN532 connected over SPI. Pass in a hardware or bitbang
SPI device & chip select digitalInOut pin. Optional IRQ pin (not used),
reset pin and debugging output."""
def __init__(self, spi, cs_pin, *, irq=None, reset=None, debug=False):
"""Create an instance of the PN532 class using SPI"""
self.debug = debug
@ -512,20 +554,25 @@ class PN532_SPI(PN532):
super().__init__(debug=debug, reset=reset)
def _wakeup(self):
"""Send any special commands/data to wake up PN532"""
with self._spi as spi:
time.sleep(1)
spi.write(bytearray([0x00]))
time.sleep(1)
def _wait_ready(self, timeout=1):
"""Poll PN532 if status byte is ready, up to `timeout` seconds"""
status = bytearray([reverse_bit(_SPI_STATREAD), 0])
t = time.monotonic()
while (time.monotonic() - t) < timeout:
timestamp = time.monotonic()
while (time.monotonic() - timestamp) < timeout:
with self._spi as spi:
time.sleep(0.02) # required
spi.write_readinto(status, status)
if reverse_bit(status[1]) == 0x01: # LSB data is read in MSB
return True # Not busy anymore!
else:
time.sleep(0.1) # pause a bit till we ask again
time.sleep(0.01) # pause a bit till we ask again
# We timed out!
return False
@ -535,21 +582,23 @@ class PN532_SPI(PN532):
frame = bytearray(count+1)
# Add the SPI data read signal byte, but LSB'ify it
frame[0] = reverse_bit(_SPI_DATAREAD)
with self._spi as spi:
time.sleep(0.01) # required
time.sleep(0.02) # required
spi.write_readinto(frame, frame)
for i in range(len(frame)):
frame[i] = reverse_bit(frame[i]) # turn LSB data to MSB
for i, val in enumerate(frame):
frame[i] = reverse_bit(val) # turn LSB data to MSB
if self.debug:
print("Reading: ", [hex(i) for i in frame[1:]])
return frame[1:]
def _write_data(self, framebytes):
# start by making a frame with data write in front, then rest of bytes, and LSBify it
reversed = [reverse_bit(x) for x in bytes([_SPI_DATAWRITE]) + framebytes]
"""Write a specified count of bytes to the PN532"""
# start by making a frame with data write in front,
# then rest of bytes, and LSBify it
rev_frame = [reverse_bit(x) for x in bytes([_SPI_DATAWRITE]) + framebytes]
if self.debug:
print("Writing: ", [hex(i) for i in reversed])
print("Writing: ", [hex(i) for i in rev_frame])
with self._spi as spi:
time.sleep(0.01) # required
spi.write(bytes(reversed))
time.sleep(0.02) # required
spi.write(bytes(rev_frame))

2
docs/conf.py
View file

@ -20,7 +20,7 @@ extensions = [
# Uncomment the below if you use native CircuitPython modules such as
# digitalio, micropython and busio. List the modules you use. Without it, the
# autodoc module docs will fail to generate with a warning.
# autodoc_mock_imports = ["digitalio", "busio"]
autodoc_mock_imports = ["digitalio", "busio", "adafruit_bus_device", "micropython"]
intersphinx_mapping = {'python': ('https://docs.python.org/3.4', None),'BusDevice': ('https://circuitpython.readthedocs.io/projects/busdevice/en/latest/', None),'CircuitPython': ('https://circuitpython.readthedocs.io/en/latest/', None)}

7
docs/index.rst
View file

@ -23,14 +23,11 @@ Table of Contents
.. toctree::
:caption: Tutorials
.. todo:: Add any Learn guide links here. If there are none, then simply delete this todo and leave
the toctree above for use later.
.. toctree::
:caption: Related Products
.. todo:: Add any product links here. If there are none, then simply delete this todo and leave
the toctree above for use later.
`PN532 NFC/RFID Breakout <https://www.adafruit.com/product/364>` and `PN532 NFC/RFID Shield <https://www.adafruit.com/product/789>`_
.. toctree::
:caption: Other Links

41
examples/pn532_simpletest.py
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@ -1,35 +1,48 @@
from Adafruit_Circuitpython_PN532 import adafruit_pn532
from digitalio import DigitalInOut, Direction, Pull
"""
This example shows connecting to the PN532 with I2C (requires clock
stretching support), SPI, or UART. SPI is best, it uses the most pins but
is the most reliable and universally supported.
After initialization, try waving various 13.56MHz RFID cards over it!
"""
import board
import time
import busio
reset_pin = DigitalInOut(board.D3)
from digitalio import DigitalInOut
from Adafruit_Circuitpython_PN532 import adafruit_pn532
# I2C connection:
#i2c = busio.I2C(board.SCL, board.SDA)
#pn532 = adafruit_pn532.PN532_I2C(i2c, debug=False, reset=reset_pin)
i2c = busio.I2C(board.SCL, board.SDA)
# Non-hardware
#pn532 = adafruit_pn532.PN532_I2C(i2c, debug=False)
# With I2C, we recommend connecting RSTPD_N (reset) to a digital pin for manual
# harware reset
reset_pin = DigitalInOut(board.D6)
# On Raspberry Pi, you must also connect a pin to P32 "H_Request" for hardware
# wakeup! this means we don't need to do the I2C clock-stretch thing
req_pin = DigitalInOut(board.D12)
pn532 = adafruit_pn532.PN532_I2C(i2c, debug=False, reset=reset_pin, req=req_pin)
# SPI connection:
#spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
#cs_pin = DigitalInOut(board.D2)
#pn532 = adafruit_pn532.PN532_SPI(spi, cs_pin, debug=False, reset=reset_pin)
#cs_pin = DigitalInOut(board.D5)
#pn532 = adafruit_pn532.PN532_SPI(spi, cs_pin, debug=False)
# UART connection
#uart = busio.UART(board.TX, board.RX, baudrate=115200, timeout=100)
#pn532 = adafruit_pn532.PN532_UART(uart, debug=False, reset=reset_pin)
#pn532 = adafruit_pn532.PN532_UART(uart, debug=False)
ic, ver, rev, support = pn532.get_firmware_version()
print('Found PN532 with firmware version: {0}.{1}'.format(ver, rev))
# Configure PN532 to communicate with MiFare cards
# Configure PN532 to communicate with MiFare cards
pn532.SAM_configuration()
print('Waiting for MiFare card...')
print('Waiting for RFID/NFC card...')
while True:
# Check if a card is available to read
uid = pn532.read_passive_target(timeout=0.25)
uid = pn532.read_passive_target(timeout=0.5)
print('.', end="", flush=True)
# Try again if no card is available.
if uid is None:

1
requirements.txt
View file

@ -1,2 +1,3 @@
Adafruit-Blinka
adafruit-circuitpython-busdevice
pyserial