Initial commit.

.gitignore

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+*.pyc

Adafruit_GPIO/GPIO.py

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+# Copyright (c) 2014 Adafruit Industries
+# Author: Tony DiCola
+#
+# 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.
+
+import platform
+
+
+OUT 	= 0
+IN 		= 1
+HIGH 	= True
+LOW 	= False
+
+
+class BaseGPIO(object):
+	"""Base class for implementing simple digital IO for a platform.
+	Implementors are expected to subclass from this and provide an implementation
+	of the setup, output, and input functions."""
+
+	def setup(self, pin, mode):
+		"""Set the input or output mode for a specified pin.  Mode should be
+		either OUT or IN."""
+		raise NotImplementedError
+
+	def output(self, pin, value):
+		"""Set the specified pin the provided high/low value.  Value should be
+		either HIGH/LOW or a boolean (true = high)."""
+		raise NotImplementedError
+
+	def input(self, pin):
+		"""Read the specified pin and return HIGH/true if the pin is pulled high,
+		or LOW/false if pulled low."""
+		raise NotImplementedError
+
+	def set_high(self, pin):
+		"""Set the specified pin HIGH."""
+		self.output(pin, HIGH)
+
+	def set_low(self, pin):
+		"""Set the specified pin LOW."""
+		self.output(pin, LOW)
+
+	def is_high(self, pin):
+		"""Return true if the specified pin is pulled high."""
+		return self.input(pin) == HIGH
+
+	def is_low(self, pin):
+		"""Return true if the specified pin is pulled low."""
+		return self.input(pin) == LOW
+
+
+class RPiGPIOAdapter(BaseGPIO):
+	"""GPIO implementation for the Raspberry Pi using the RPi.GPIO library."""
+
+	def __init__(self, rpi_gpio, mode=None):
+		self.rpi_gpio = rpi_gpio
+		# Suppress warnings about GPIO in use.
+		rpi_gpio.setwarnings(False)
+		if mode == rpi_gpio.BOARD or mode == rpi_gpio.BCM:
+			rpi_gpio.setmode(mode)
+		elif mode is not None:
+			raise ValueError('Unexpected value for mode.  Must be BOARD or BCM.')
+		else:
+			# Default to BCM numbering if not told otherwise.
+			rpi_gpio.setmode(rpi_gpio.BCM)
+
+	def setup(self, pin, mode):
+		"""Set the input or output mode for a specified pin.  Mode should be
+		either OUTPUT or INPUT.
+		"""
+		self.rpi_gpio.setup(pin, self.rpi_gpio.IN if mode == IN else \
+								 self.rpi_gpio.OUT)
+
+	def output(self, pin, value):
+		"""Set the specified pin the provided high/low value.  Value should be
+		either HIGH/LOW or a boolean (true = high).
+		"""
+		self.rpi_gpio.output(pin, value)
+
+	def input(self, pin):
+		"""Read the specified pin and return HIGH/true if the pin is pulled high,
+		or LOW/false if pulled low.
+		"""
+		return self.rpi_gpio.input(pin)
+
+
+class AdafruitBBIOAdapter(BaseGPIO):
+	"""GPIO implementation for the Beaglebone Black using the Adafruit_BBIO
+	library.
+	"""
+
+	def __init__(self, bbio_gpio):
+		self.bbio_gpio = bbio_gpio
+
+	def setup(self, pin, mode):
+		"""Set the input or output mode for a specified pin.  Mode should be
+		either OUTPUT or INPUT.
+		"""
+		self.bbio_gpio.setup(pin, self.bbio_gpio.IN if mode == IN else \
+								  self.bbio_gpio.OUT)
+
+	def output(self, pin, value):
+		"""Set the specified pin the provided high/low value.  Value should be
+		either HIGH/LOW or a boolean (true = high).
+		"""
+		self.bbio_gpio.output(pin, value)
+
+	def input(self, pin):
+		"""Read the specified pin and return HIGH/true if the pin is pulled high,
+		or LOW/false if pulled low.
+		"""
+		return self.bbio_gpio.input(pin)
+
+
+def get_platform_gpio(plat=platform.platform(), **keywords):
+	"""Attempt to return a GPIO instance for the platform which the code is being
+	executed on.  Currently supports only the Raspberry Pi using the RPi.GPIO
+	library and Beaglebone Black using the Adafruit_BBIO library.  Will throw an
+	exception if a GPIO instance can't be created for the current platform.  The
+	returned GPIO object is an instance of BaseGPIO.
+	"""
+	if plat is None:
+		raise RuntimeError('Could not determine platform type.')
+
+	# TODO: Is there a better way to check if running on BBB or Pi?  Relying on
+	# the architecture name is brittle because new boards running armv6 or armv7
+	# might come along and conflict with this simple identification scheme.
+
+	# Handle Raspberry Pi
+	# Platform output on Raspbian testing/jessie ~May 2014:
+	# Linux-3.10.25+-armv6l-with-debian-7.4
+	if plat.lower().find('armv6l-with-debian') > -1:
+		import RPi.GPIO
+		return RPiGPIOAdapter(RPi.GPIO, **keywords)
+
+	# Handle Beaglebone Black
+	# Platform output on Debian ~May 2014:
+	# Linux-3.8.13-bone47-armv7l-with-debian-7.4
+	if plat.lower().find('armv7l-with-debian') > -1:
+		import Adafruit_BBIO.GPIO
+		return AdafruitBBIOAdapter(Adafruit_BBIO.GPIO, **keywords)
+
+	# Couldn't determine platform, raise error.
+	raise RuntimeError('Unsupported platform: {0}'.format(plat))