# 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 Adafruit_GPIO.Platform as Platform
OUT = 0
IN = 1
HIGH = True
LOW = False
RISING = 1
FALLING = 2
BOTH = 3
PUD_OFF = 0
PUD_DOWN = 1
PUD_UP = 2
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, pull_up_down=PUD_OFF):
"""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
# Basic implementation of multiple pin methods just loops through pins and
# processes each one individually. This is not optimal, but derived classes can
# provide a more optimal implementation that deals with groups of pins
# simultaneously.
# See MCP230xx or PCF8574 classes for examples of optimized implementations.
def output_pins(self, pins):
"""Set multiple pins high or low at once. Pins should be a dict of pin
name to pin value (HIGH/True for 1, LOW/False for 0). All provided pins
will be set to the given values.
"""
# General implementation just loops through pins and writes them out
# manually. This is not optimized, but subclasses can choose to implement
# a more optimal batch output implementation. See the MCP230xx class for
# example of optimized implementation.
for pin, value in iter(pins.items()):
self.output(pin, value)
def setup_pins(self, pins):
"""Setup multiple pins as inputs or outputs at once. Pins should be a
dict of pin name to pin type (IN or OUT).
"""
# General implementation that can be optimized by derived classes.
for pin, value in iter(pins.items()):
self.setup(pin, value)
def input_pins(self, pins):
"""Read multiple pins specified in the given list and return list of pin values
GPIO.HIGH/True if the pin is pulled high, or GPIO.LOW/False if pulled low.
"""
# General implementation that can be optimized by derived classes.
return [self.input(pin) for pin in pins]
def add_event_detect(self, pin, edge):
"""Enable edge detection events for a particular GPIO channel. Pin
should be type IN. Edge must be RISING, FALLING or BOTH.
"""
raise NotImplementedError
def remove_event_detect(self, pin):
"""Remove edge detection for a particular GPIO channel. Pin should be
type IN.
"""
raise NotImplementedError
def add_event_callback(self, pin, callback):
"""Add a callback for an event already defined using add_event_detect().
Pin should be type IN.
"""
raise NotImplementedError
def event_detected(self, pin):
"""Returns True if an edge has occured on a given GPIO. You need to
enable edge detection using add_event_detect() first. Pin should be
type IN.
"""
raise NotImplementedError
def wait_for_edge(self, pin, edge):
"""Wait for an edge. Pin should be type IN. Edge must be RISING,
FALLING or BOTH."""
raise NotImplementedError
def cleanup(self, pin=None):
"""Clean up GPIO event detection for specific pin, or all pins if none
is specified.
"""
raise NotImplementedError
# helper functions useful to derived classes
def _validate_pin(self, pin):
# Raise an exception if pin is outside the range of allowed values.
if pin < 0 or pin >= self.NUM_GPIO:
raise ValueError('Invalid GPIO value, must be between 0 and {0}.'.format(self.NUM_GPIO))
def _bit2(self, src, bit, val):
bit = 1 << bit
return (src | bit) if val else (src & ~bit)
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)
# Setup board pin mode.
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)
# Define mapping of Adafruit GPIO library constants to RPi.GPIO constants.
self._dir_mapping = { OUT: rpi_gpio.OUT,
IN: rpi_gpio.IN }
self._pud_mapping = { PUD_OFF: rpi_gpio.PUD_OFF,
PUD_DOWN: rpi_gpio.PUD_DOWN,
PUD_UP: rpi_gpio.PUD_UP }
self._edge_mapping = { RISING: rpi_gpio.RISING,
FALLING: rpi_gpio.FALLING,
BOTH: rpi_gpio.BOTH }
def setup(self, pin, mode, pull_up_down=PUD_OFF):
"""Set the input or output mode for a specified pin. Mode should be
either OUTPUT or INPUT.
"""
self.rpi_gpio.setup(pin, self._dir_mapping[mode],
pull_up_down=self._pud_mapping[pull_up_down])
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)
def input_pins(self, pins):
"""Read multiple pins specified in the given list and return list of pin values
GPIO.HIGH/True if the pin is pulled high, or GPIO.LOW/False if pulled low.
"""
# maybe rpi has a mass read... it would be more efficient to use it if it exists
return [self.rpi_gpio.input(pin) for pin in pins]
def add_event_detect(self, pin, edge, callback=None, bouncetime=-1):
"""Enable edge detection events for a particular GPIO channel. Pin
should be type IN. Edge must be RISING, FALLING or BOTH. Callback is a
function for the event. Bouncetime is switch bounce timeout in ms for
callback
"""
kwargs = {}
if callback:
kwargs['callback']=callback
if bouncetime > 0:
kwargs['bouncetime']=bouncetime
self.rpi_gpio.add_event_detect(pin, self._edge_mapping[edge], **kwargs)
def remove_event_detect(self, pin):
"""Remove edge detection for a particular GPIO channel. Pin should be
type IN.
"""
self.rpi_gpio.remove_event_detect(pin)
def add_event_callback(self, pin, callback):
"""Add a callback for an event already defined using add_event_detect().
Pin should be type IN.
"""
self.rpi_gpio.add_event_callback(pin, callback)
def event_detected(self, pin):
"""Returns True if an edge has occured on a given GPIO. You need to
enable edge detection using add_event_detect() first. Pin should be
type IN.
"""
return self.rpi_gpio.event_detected(pin)
def wait_for_edge(self, pin, edge):
"""Wait for an edge. Pin should be type IN. Edge must be RISING,
FALLING or BOTH.
"""
self.rpi_gpio.wait_for_edge(pin, self._edge_mapping[edge])
def cleanup(self, pin=None):
"""Clean up GPIO event detection for specific pin, or all pins if none
is specified.
"""
if pin is None:
self.rpi_gpio.cleanup()
else:
self.rpi_gpio.cleanup(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
# Define mapping of Adafruit GPIO library constants to RPi.GPIO constants.
self._dir_mapping = { OUT: bbio_gpio.OUT,
IN: bbio_gpio.IN }
self._pud_mapping = { PUD_OFF: bbio_gpio.PUD_OFF,
PUD_DOWN: bbio_gpio.PUD_DOWN,
PUD_UP: bbio_gpio.PUD_UP }
self._edge_mapping = { RISING: bbio_gpio.RISING,
FALLING: bbio_gpio.FALLING,
BOTH: bbio_gpio.BOTH }
def setup(self, pin, mode, pull_up_down=PUD_OFF):
"""Set the input or output mode for a specified pin. Mode should be
either OUTPUT or INPUT.
"""
self.bbio_gpio.setup(pin, self._dir_mapping[mode],
pull_up_down=self._pud_mapping[pull_up_down])
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 input_pins(self, pins):
"""Read multiple pins specified in the given list and return list of pin values
GPIO.HIGH/True if the pin is pulled high, or GPIO.LOW/False if pulled low.
"""
# maybe bbb has a mass read... it would be more efficient to use it if it exists
return [self.bbio_gpio.input(pin) for pin in pins]
def add_event_detect(self, pin, edge, callback=None, bouncetime=-1):
"""Enable edge detection events for a particular GPIO channel. Pin
should be type IN. Edge must be RISING, FALLING or BOTH. Callback is a
function for the event. Bouncetime is switch bounce timeout in ms for
callback
"""
kwargs = {}
if callback:
kwargs['callback']=callback
if bouncetime > 0:
kwargs['bouncetime']=bouncetime
self.bbio_gpio.add_event_detect(pin, self._edge_mapping[edge], **kwargs)
def remove_event_detect(self, pin):
"""Remove edge detection for a particular GPIO channel. Pin should be
type IN.
"""
self.bbio_gpio.remove_event_detect(pin)
def add_event_callback(self, pin, callback, bouncetime=-1):
"""Add a callback for an event already defined using add_event_detect().
Pin should be type IN. Bouncetime is switch bounce timeout in ms for
callback
"""
kwargs = {}
if bouncetime > 0:
kwargs['bouncetime']=bouncetime
self.bbio_gpio.add_event_callback(pin, callback, **kwargs)
def event_detected(self, pin):
"""Returns True if an edge has occured on a given GPIO. You need to
enable edge detection using add_event_detect() first. Pin should be
type IN.
"""
return self.bbio_gpio.event_detected(pin)
def wait_for_edge(self, pin, edge):
"""Wait for an edge. Pin should be type IN. Edge must be RISING,
FALLING or BOTH.
"""
self.bbio_gpio.wait_for_edge(pin, self._edge_mapping[edge])
def cleanup(self, pin=None):
"""Clean up GPIO event detection for specific pin, or all pins if none
is specified.
"""
if pin is None:
self.bbio_gpio.cleanup()
else:
self.bbio_gpio.cleanup(pin)
class AdafruitMinnowAdapter(BaseGPIO):
"""GPIO implementation for the Minnowboard + MAX using the mraa library"""
def __init__(self,mraa_gpio):
self.mraa_gpio = mraa_gpio
# Define mapping of Adafruit GPIO library constants to mraa constants
self._dir_mapping = { OUT: self.mraa_gpio.DIR_OUT,
IN: self.mraa_gpio.DIR_IN }
self._pud_mapping = { PUD_OFF: self.mraa_gpio.MODE_STRONG,
PUD_UP: self.mraa_gpio.MODE_HIZ,
PUD_DOWN: self.mraa_gpio.MODE_PULLDOWN }
self._edge_mapping = { RISING: self.mraa_gpio.EDGE_RISING,
FALLING: self.mraa_gpio.EDGE_FALLING,
BOTH: self.mraa_gpio.EDGE_BOTH }
def setup(self,pin,mode):
"""Set the input or output mode for a specified pin. Mode should be
either DIR_IN or DIR_OUT.
"""
self.mraa_gpio.Gpio.dir(self.mraa_gpio.Gpio(pin),self._dir_mapping[mode])
def output(self,pin,value):
"""Set the specified pin the provided high/low value. Value should be
either 1 (ON or HIGH), or 0 (OFF or LOW) or a boolean.
"""
self.mraa_gpio.Gpio.write(self.mraa_gpio.Gpio(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.mraa_gpio.Gpio.read(self.mraa_gpio.Gpio(pin))
def add_event_detect(self, pin, edge, callback=None, bouncetime=-1):
"""Enable edge detection events for a particular GPIO channel. Pin
should be type IN. Edge must be RISING, FALLING or BOTH. Callback is a
function for the event. Bouncetime is switch bounce timeout in ms for
callback
"""
kwargs = {}
if callback:
kwargs['callback']=callback
if bouncetime > 0:
kwargs['bouncetime']=bouncetime
self.mraa_gpio.Gpio.isr(self.mraa_gpio.Gpio(pin), self._edge_mapping[edge], **kwargs)
def remove_event_detect(self, pin):
"""Remove edge detection for a particular GPIO channel. Pin should be
type IN.
"""
self.mraa_gpio.Gpio.isrExit(self.mraa_gpio.Gpio(pin))
def wait_for_edge(self, pin, edge):
"""Wait for an edge. Pin should be type IN. Edge must be RISING,
FALLING or BOTH.
"""
self.bbio_gpio.wait_for_edge(self.mraa_gpio.Gpio(pin), self._edge_mapping[edge])
def get_platform_gpio(**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.
"""
plat = Platform.platform_detect()
if plat == Platform.RASPBERRY_PI:
import RPi.GPIO
return RPiGPIOAdapter(RPi.GPIO, **keywords)
elif plat == Platform.BEAGLEBONE_BLACK:
import Adafruit_BBIO.GPIO
return AdafruitBBIOAdapter(Adafruit_BBIO.GPIO, **keywords)
elif plat == Platform.MINNOWBOARD:
import mraa
return AdafruitMinnowAdapter(mraa, **keywords)
elif plat == Platform.JETSON_NANO:
import Jetson.GPIO
return RPiGPIOAdapter(Jetson.GPIO, **keywords)
elif plat == Platform.UNKNOWN:
raise RuntimeError('Could not determine platform.')
