433Mhz Pi GPIO monitor

#!/usr/bin/env python2.7
# demo of "BOTH" bi-directional edge detection
# script by Alex Eames http://RasPi.tv
# http://raspi.tv/?p=6791

import RPi.GPIO as GPIO
from time import sleep     # this lets us have a time delay (see line 12)
from datetime import datetime


portToUse = 27
lastTime = datetime.now()

GPIO.setmode(GPIO.BCM)     # set up BCM GPIO numbering
GPIO.setup(portToUse, GPIO.IN)    # set GPIO as input (button)

# Define a threaded callback function to run in another thread when events are detected
def my_callback(channel):
    global lastTime
    nowTime = datetime.now()
    delta = nowTime - lastTime
    lastTime = nowTime

    if GPIO.input(portToUse):     # if port == 1
        print "%d ms Rising on %d " % (delta.microseconds, portToUse)
    else:                  # if port != 1
        print "%d ms Falling on %d " % (delta.microseconds, portToUse)

# when a changing edge is detected on port 27, regardless of whatever
# else is happening in the program, the function my_callback will be run
GPIO.add_event_detect(portToUse, GPIO.BOTH, callback=my_callback)

print "Program will finish after 30 seconds or if you press CTRL+C\n"
print "Make sure you have a button connected, pulled down through 10k resistor"
print "to GND and wired so that when pressed it connects"
print "GPIO port 27 (pin 22) to GND (pin 6) through a ~1k resistor\n"

print "Also put a 100 nF capacitor across your switch for hardware debouncing"
print "This is necessary to see the effect we're looking for"
raw_input("Press Enter when ready\n>")

try:
    print "When pressed, you'll see: Rising Edge detected on %d" % portToUse
    print "When released, you'll see: Falling Edge detected on %d"  % portToUse
    sleep(30)         # wait 30 seconds
    print "Time's up. Finished!"

finally:                   # this block will run no matter how the try block exits
    GPIO.cleanup()         # clean up after yourself