mraa/examples/python/gpio_advanced.py

#!/usr/bin/env python

# Author: Brendan Le Foll <brendan.le.foll@intel.com>
# Copyright (c) 2014 Intel Corporation.
#
# 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
#
# Example Usage: Triggers ISR upon GPIO state change

import mraa
import time
import sys

class Counter:
    count = 0

c = Counter()

# inside a python interrupt you cannot use 'basic' types so you'll need to use
# objects
def isr_routine(gpio):
    print("pin " + repr(gpio.getPin(True)) + " = " + repr(gpio.read()))
    c.count += 1

# GPIO
pin = 6;

try:
    # initialise GPIO
    x = mraa.Gpio(pin)

    print("Starting ISR for pin " + repr(pin))

    # set direction and edge types for interrupt
    x.dir(mraa.DIR_IN)
    x.isr(mraa.EDGE_BOTH, isr_routine, x)

    # wait until ENTER is pressed
    var = raw_input("Press ENTER to stop")
    x.isrExit()
except ValueError as e:
    print(e)