pi-shutdown.py

#!/usr/bin/python

# MIT License
#
# Copyright (c) 2019 Donato Rimenti
# Copyright (c) 2019 George Ilyes
#
# 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
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# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

# shutdown/reboot(/power on) Raspberry Pi with pushbutton

import RPi.GPIO as GPIO
from subprocess import call
from datetime import datetime
import time
from signal import pause

# pushbutton connected to this GPIO pin, using pin 5 also has the benefit of
# waking / powering up Raspberry Pi when button is pressed
shutdownPin = 5

# if button pressed for at least this long then shut down. if less then reboot.
shutdownMinSeconds = 3

# button debounce time in seconds
debounceSeconds = 0.01

# whether the button is normally open or closed
normallyOpen = False

GPIO.setmode(GPIO.BOARD)
GPIO.setup(shutdownPin, GPIO.IN, pull_up_down=GPIO.PUD_UP)

buttonPressedTime = None


def buttonStateChanged(pin):
    global buttonPressedTime

    incomingSignal = GPIO.input(pin)

    # inverts the signal if the button is normally closed
    if not (normallyOpen):
        incomingSignal = not incomingSignal

    if not (incomingSignal):
        # button is down
        if buttonPressedTime is None:
            buttonPressedTime = datetime.now()
    else:
        # button is up
        if buttonPressedTime is not None:
            elapsed = (datetime.now() - buttonPressedTime).total_seconds()
            buttonPressedTime = None
            if elapsed >= shutdownMinSeconds:
                # button pressed for more than specified time, shutdown
                call(['shutdown', '-h', 'now'], shell=False)
            elif elapsed >= debounceSeconds:
                # button pressed for a shorter time, reboot
                call(['shutdown', '-r', 'now'], shell=False)


# subscribe to button presses
GPIO.add_event_detect(shutdownPin, GPIO.BOTH, callback=buttonStateChanged)

# wait forever
pause()