Raspberry Pi3 Shutdown button with LED indicator

README.md

Installation

1. Put shutdown_button.py to /usr/local/bin/
2. Put shutdown_button.service to /etc/systemd/system/
3. Enable service systemctl enable shutdown_button.service
4. Start service systemctl start shutdown_button.service
5. Enjoy!

Misc

shutdown_button.py

#!/usr/bin/python3
# -*- coding: utf-8 -*-
# example gpiozero code that could be used to have a reboot
#  and a shutdown function on one GPIO button
# scruss - 2017-10
from gpiozero import Button, LED
from signal import pause, signal, SIGINT
from sys import exit
from subprocess import check_call

use_button=3 # lowest button on PiTFT+
use_led=17
held_for=0.0

def signal_handler(sig, frame):
        led.off()
        exit(0)

def rls():
        global held_for
        if (held_for > 1.0):
                led.off()
                check_call(['/sbin/poweroff'])
        else:
                held_for = 0.0

def hld():
        # callback for when button is held
        #  is called every hold_time seconds
        global held_for
        # need to use max() as held_time resets to zero on last callback
        held_for = max(held_for, button.held_time + button.hold_time)

led = LED(use_led)
led.on()
button=Button(use_button, hold_time=1.0, hold_repeat=True)
button.when_held = hld
button.when_released = rls

signal(SIGINT, signal_handler)
pause() # wait forever

shutdown_button.service

[Unit]
Description=GPIO shutdown button
After=network.target

[Service]
Type=simple
Restart=always
RestartSec=1
User=root
ExecStart=/usr/bin/python3 /usr/local/bin/shutdown_button.py

[Install]
WantedBy=multi-user.target