Tweeting Letterbox. Blog post: http://jamesmedd.tumblr.com/post/35270913619/raspberry-pi-tweeting-letterbox

tweeting_letterbox.py

# Tweeting Letterbox
# by James Medd
# November 2012 (original version)
# http://jamesmedd.co.uk/

#!/usr/bin/python 

import picamera
import RPi.GPIO as GPIO
import sys
import time
from twython import Twython

#OAuth details go here
CONSUMER_KEY = ""
CONSUMER_SECRET = ""
ACCESS_TOKEN = ""
ACCESS_TOKEN_SECRET = ""

#initialise Camera
camera = picamera.PiCamera()

#set input GPIO pin
GPIO.setmode(GPIO.BOARD)
GPIO.setup(11, GPIO.IN)

twit = Twython(CONSUMER_KEY, CONSUMER_SECRET, ACCESS_TOKEN, ACCESS_TOKEN_SECRET)

#timestamp, capture, and tweet an image
def capture_tweet():	
	timestamp = time.strftime("%d%m%Y-%H%M%S")
	camera.capture(timestamp + ".jpg") #save image to disk
	image = open(timestamp + ".jpg", 'rb')
	timestamp = "@Username " + timestamp
	twit.update_status_with_media(status=timestamp, media=image)
	print "Tweeted image at " + timestamp #make a record in the Python output

#try/except for tidy starting/stopping of script
try:
	print "Tweeting Letterbox initialised. Exit using Ctrl + c."
	#loop to check PIR state/trigger a tweet (exit using Ctrl+C)
	while True:
		ir_val = GPIO.input(11)
		if not ir_val:
			time.sleep(0.5) #wait before checking again if nothing detected
		elif ir_val:
			capture_tweet() #capture and tweet image if triggered
			while ir_val:
				ir_val = GPIO.input(11)
				time.sleep(0.5) #wait for sensor to reset/movement to stop before checking again
		else:
			print "Error"
except KeyboardInterrupt:
	print "\nExiting.",
	sys.exit()

Updated this morning, after discovering that 'time.strftime()' provided a timestamp with the kind of padding I wanted out of the box, eliminating the need for my messy, 'datetime'-based function.

Brilliant idea, hadn't thought of monitoring the post! Excellent to monitor when parcels I am waiting for are received!

Just wondered if you have any idea how I can resolve this issue though:

UnicodeDecodeError: 'ascii' codec can't decode byte 0xff in position 221: ordinal not in range(128)

Any advice appreciated as Google has failed me on this one :)

@anddav87: I've not come across that issue before, and I'm not sure I can troubleshoot it for you. Sorry!

Updated again this morning in line with a version I'm hoping will appear in MagPi soon. Includes a tidier start/stop using try/except.

Added an update to use the Raspberry Pi Camera module instead of a webcam. Also updated Twython-related code in line with their documentation guidelines etc.