Refactoring to save memory

.travis.yml

@@ -25,7 +25,7 @@ install:
 - pip install circuitpython-build-tools Sphinx sphinx-rtd-theme
 - pip install --force-reinstall pylint==1.9.2
 script:
-- pylint adafruit_pn532.py
+- pylint adafruit_pn532/*.py
 - ([[ ! -d "examples" ]] || pylint --disable=missing-docstring,invalid-name,bad-whitespace
   examples/*.py)
 - circuitpython-build-bundles --filename_prefix adafruit-circuitpython-pn532 --library_location .

adafruit_pn532.py → adafruit_pn532/adafruit_pn532.py

@@ -46,11 +46,8 @@
 * Adafruit's Bus Device library: https://github.com/adafruit/Adafruit_CircuitPython_BusDevice
 """
 
-
 import time
 from digitalio import Direction
-import adafruit_bus_device.i2c_device as i2c_device
-import adafruit_bus_device.spi_device as spi_device
 
 from micropython import const
 
@@ -105,13 +102,6 @@
 
 _WAKEUP                        = const(0x55)
 
-_SPI_STATREAD                  = const(0x02)
-_SPI_DATAWRITE                 = const(0x01)
-_SPI_DATAREAD                  = const(0x03)
-_SPI_READY                     = const(0x01)
-
-_I2C_ADDRESS                   = const(0x24)
-
 _MIFARE_ISO14443A              = const(0x00)
 
 # Mifare Commands
@@ -186,22 +176,12 @@ def _reset(pin):
     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
-        result += (num & 1)
-        num >>= 1
-    return result
-
-
 
 class BusyError(Exception):
     """Base class for exceptions in this module."""
     pass
 
+
 class PN532:
     """PN532 driver base, must be extended for I2C/SPI/UART interfacing"""
 
@@ -464,167 +444,3 @@ def ntag2xx_read_block(self, block_number):
         not read then None will be returned.
         """
         return self.mifare_classic_read_block(block_number)[0:4] # only 4 bytes per page
-
-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.
-        Optional IRQ pin (not used), reset pin and debugging output.
-        """
-        self.debug = debug
-        self._irq = irq
-        self._uart = uart
-        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
-
-    def _read_data(self, count):
-        """Read a specified count of bytes from the PN532."""
-        frame = self._uart.read(count)
-        if not frame:
-            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!
-        self._uart.write(framebytes)
-
-class PN532_I2C(PN532):
-    """Driver for the PN532 connected over I2C."""
-    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): # 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)
-        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(0.05)  # lets ask again soon!
-        # Timed out!
-        return False
-
-    def _read_data(self, count):
-        """Read a specified count of bytes from the PN532."""
-        # Build a read request frame.
-        frame = bytearray(count+1)
-        with self._i2c as i2c:
-            i2c.readinto(frame, end=1) # read status byte!
-            if frame[0] != 0x01:             # not ready
-                raise BusyError
-            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."""
-    def __init__(self, spi, cs_pin, *, irq=None, reset=None, debug=False):
-        """Create an instance of the PN532 class using SPI"""
-        self.debug = debug
-        self._irq = irq
-        self._spi = spi_device.SPIDevice(spi, cs_pin)
-        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])) #pylint: disable=no-member
-            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])
-
-        timestamp = time.monotonic()
-        while (time.monotonic() - timestamp) < timeout:
-            with self._spi as spi:
-                time.sleep(0.02)   # required
-                spi.write_readinto(status, status) #pylint: disable=no-member
-            if reverse_bit(status[1]) == 0x01:  # LSB data is read in MSB
-                return True      # Not busy anymore!
-            else:
-                time.sleep(0.01)  # pause a bit till we ask again
-        # We timed out!
-        return False
-
-    def _read_data(self, count):
-        """Read a specified count of bytes from the PN532."""
-        # Build a read request frame.
-        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(0.02)   # required
-            spi.write_readinto(frame, frame) #pylint: disable=no-member
-        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):
-        """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 rev_frame])
-        with self._spi as spi:
-            time.sleep(0.02)   # required
-            spi.write(bytes(rev_frame)) #pylint: disable=no-member

adafruit_pn532/i2c.py

@@ -0,0 +1,111 @@
+# Adafruit PN532 NFC/RFID control library.
+# Author: Tony DiCola
+#
+# The MIT License (MIT)
+#
+# Copyright (c) 2015-2018 Adafruit Industries
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+"""
+``adafruit_pn532.i2c``
+====================================================
+
+This module will let you communicate with a PN532 RFID/NFC shield or breakout
+using I2C.
+
+* Author(s): Original Raspberry Pi code by Tony DiCola, CircuitPython by ladyada,
+             refactor by Carter Nelson
+
+"""
+
+__version__ = "0.0.0-auto.0"
+__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_PN532.git"
+
+import time
+import adafruit_bus_device.i2c_device as i2c_device
+from digitalio import Direction
+from micropython import const
+from adafruit_pn532.adafruit_pn532 import PN532, BusyError, _reset
+
+# pylint: disable=bad-whitespace
+_I2C_ADDRESS                   = const(0x24)
+
+class PN532_I2C(PN532):
+    """Driver for the PN532 connected over I2C."""
+    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): # 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)
+        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(0.05)  # lets ask again soon!
+        # Timed out!
+        return False
+
+    def _read_data(self, count):
+        """Read a specified count of bytes from the PN532."""
+        # Build a read request frame.
+        frame = bytearray(count+1)
+        with self._i2c as i2c:
+            i2c.readinto(frame, end=1) # read status byte!
+            if frame[0] != 0x01:             # not ready
+                raise BusyError
+            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)