#!/usr/bin/python

# PiPower
# Copyright 2017 (c) Mark van Renswoude
#
# Yet another power supply for the Raspberry Pi.
# Designed to run on an ATTiny85 with a self-locking button.

import RPi.GPIO as GPIO
import time
import os

GPIO.setmode(GPIO.BCM)
GPIO.setup(15, GPIO.OUT)
GPIO.setup(18, GPIO.IN, pull_up_down=GPIO.PUD_DOWN)

hasShutdown = False


def shutdownSignal(channel):
  print "PiPower: shutting down"
  os.system('shutdown -h now')
  hasShutdown = true


GPIO.add_event_detect(18, GPIO.RISING, callback=shutdownSignal, bouncetime=300)
GPIO.output(15, GPIO.HIGH)


try:
  print "PiPower: waiting for signal"

  while not hasShutdown:
    time.sleep(1)

  print "PiPower: exiting"
  GPIO.cleanup()
except KeyboardInterrupt:
  GPIO.cleanup()