Kindle digital photo frame part 2

Now that I can SSH into the Kindle I need to figure out the functions that I need. I want the Kindle to cycle through me and my gf's photos every 3 hours. Apart from that, I want to be able to upload photos of cute cats or love messages onto the internet, and those will show up, ONLY ONCE, on the Kindle.

For cycling photos, I need to:

1. Wake up the Kindle from sleeping
2. Put it to sleep again.

(1) is easy to find. The command, lipc-set-prop com.lab126.powerd wakeUp 1, will wake up the Kindle. (http://www.mobileread.com/. forums/archive/index.php/t-160328.html) Fortunately, cron works even when the Kindle is sleeping, so cycling photos is definitely possible.

(2) took me a while to find. The command is, /usr/bin/powerd_test -p . (http://www.mobileread.com/forums/showthread.php?t=220810) It works for waking up the Kindle as well, so now I can simply cycle my photos by running this command twice!

For displaying my uploaded pictures, I need to:

1. Setup a server backend for uploading images
2. Periodically downloading them into the Kindle
3. Display the images occasionally, deleting them after they've been displayed.

For (1), I can simply use OpenShift and CakePHP to setup a backend for uploading and storing images. I've familiarized myself with that setup thanks to a previous competition, so no worries here.

(2), I can simply write a script for downloading the images from my backend and add it to crontab. I can even turn on wireless using cron, no issues here.

(3), I had no idea to detect which image is being displayed on screen. Thankfully, I found this page https://github.com/yifanlu/OpenBlanket/blob/master/screensaver.c, line 363 of the code shows that the last screensaver displayed is stored at "/var/local/blanket/screensaver/last_ss". I can use this while waking up the Kindle, to delete the images shown before.

Stay tuned to the next part!