A home security system. Logs when windows are opened or closed to the syslog, and gives you an indicator panel so you can see at a glance whether a you've left something open before walking out of the house!

security.py

import piface.pfio
import time
import sys
import syslog

class SecurityIndicator:
        """ A switch and LED link: Displays light when switch is closed """

        def __init__(self, pin_pair, label):
                self.pin_pair = pin_pair
                self.label = label
                self.laststatus = ""
                self.poll()

        def poll(self):
                if piface.pfio.digital_read(self.pin_pair) == 1:
                        if self.laststatus != 'closed':
                                piface.pfio.digital_write(self.pin_pair, 1)
                                self.log(self.label + ' is CLOSED')
                                self.laststatus = 'closed'
                else:
                        if self.laststatus != 'open':
                                piface.pfio.digital_write(self.pin_pair, 0)
                                self.log(self.label + ' is OPEN')
                                self.laststatus = 'open'

        def log(self, message):
                # Echo message
                print(message + ' at ' + time.strftime("%a, %d %b %Y %H:%M:%S +0000", time.gmtime()))

                # And for good measure, log entry to auth log
                syslog.syslog(syslog.LOG_AUTH | syslog.LOG_INFO, message)

def main(argv):
        piface.pfio.init()

        # Initialise our indicator switches
        indicators = ['Front Door', 'Study window', 'Study door', 'Bedroom Window', 'Back door', 'Living room window', 'Kitchen window', 'Bathroom window']
        indicator_obj = [];
        cnt = 0
        for switch in indicators:
                indicator_obj.append(SecurityIndicator(cnt, switch))
                cnt = cnt + 1

        # Loop and check indicators
        while True:
                for indicator in indicator_obj:
                        indicator.poll()

                time.sleep(0.05)

if __name__ == "__main__":
    sys.exit(main(sys.argv))