Simple Raspberry Pi-based CCTV app. Requires Pi camera, Dropbox account

cctv.py

#!/usr/bin/python

from picamera import PiCamera
from time import sleep
from subprocess import call
import os
import sys

# CONSTANTS
KEEP_FILES = 10
WARM_TIME = 3
SOURCE_BASE = "~/stills/"
SCRIPT_BASE = "~/dropbox-uploader/dropbox_uploader.sh -q "

# NOTE dropbox_uploader.sh available from https://github.com/andreafabrizi/Dropbox-Uploader

# GLOBAL VARIABLES
cctv = PiCamera()
imageCount = 1

# FUNCTIONS
def takepic(destinationPath):
    global WARM_TIME

    cctv.start_preview()
    sleep(WARM_TIME)
    cctv.capture(destinationPath)
    cctv.stop_preview()


# PROGRAM START
print('Starting PiCamera...')
cctv.resolution = (1024, 768)
cctv.led = False

# Picture right way up when Pi in landscape, power cable below
cctv.rotation = 90

# TODO read in current image count from /still

while True:
    # Get the name of the next photo to take and
    # its save path in the filesystem
    imageName = "img{:04d}.jpg".format(imageCount)
    piPath = SOURCE_BASE + imageName

    # Take the image and save at the specified path
    takepic(piPath)

    # Check if we have more than 'KEEP_FILES' photos
    if imageCount > KEEP_FILES:
        # Delete the oldest image
        fileName = "img{:04d}.jpg".format(imageCount - KEEP_FILES)
        filePath = SOURCE_BASE + fileName
        if os.path.exists(filePath):
            # There is an image to delete, so delete it from the filesystem...
            print('Deleting: ' + filePath)
            os.remove(filePath)

            # ...and from Dropbox
            shellCommand = SCRIPT_BASE + "delete " + fileName
            call([shellCommand], shell=True)
        else:
            print("[ERROR] Cannot find " + fileName + " for deletion")

    # Upload the latest photo
    shellCommand = SCRIPT_BASE + "upload " + piPath + " " + imageName
    print("Uploading: " + piPath)
    call([shellCommand], shell=True)

    # Increment the count and cycle at 10,000 images
    imageCount = imageCount + 1
    if imageCount == 9999:
        imageCount = 1

    # Sleep between images
    sleep(60 - WARM_TIME)