############################################
# As published in www.internetdelascosas.cl
# Feel free to use and modify
# PIR is connected as follows
# Vdd P9.4
# Gnd P9.1
# Out P9.15
# ref : http://www.gigamegablog.com/2012/03/16/beaglebone-coding-101-buttons-and-pwm/
############################################

import os
from time import sleep

os.system("echo 48 > /sys/class/gpio/export")

while(True):

        f = open("/sys/class/gpio/gpio48/value","r") # reading P9.15
        datos  = f.read()
        vect   = datos.split('\x00')
        switch = int(vect[0])                 # convert to int type
        if switch == 0:
                print( "Not sensing presence")
                sleep(1)
        else:
                print ( "Sensing presence")
                sleep(1)
        f.close

# To disable pin use
# os.system("echo 48 > /sys/class/gpio/unexport")