OK Think I have a profile I created to do this for you. Just one drawback, you need SecureSettings and the pro version of it, which in the UK is 95 pence. This is needed to reboot into recovery itself.
Let me just finalise testing.
Edit > OK so this zip contains a folder called clockworkmod. This must replace your existing clockworkmod on your (INTERNAL) sdcard (when unzipped)
Within there you have /backup/auto_backup where your nandroid goes, and 1x archive location currently also set to /backup/auto_archive
What happens is the profile triggers at 4am saturday (when you're asleep). It runs a bash script I wrote.
The script, deletes whatever is in auto_archive and puts auto_backup in archive (this way when you fill up auto_backup in a minute, you always have 1 new and 1 old backup)
Then, the script puts a file that tells recovery what to do. It copies a file to /cache/recovery/extendedcommand which tells recovery what to do when it boots up.
Then heres the slightly annoying bit. The profile then tells securesettings (pro - which you have to pay for) to reboot into recovery.
Recovery reads extended command and does backup, completes and boots back into android.
OK so I didnt figure out how to get the extendedcommand to tell recovery to backup to extSdCard so it backs up to internal.
You CAN change the location of auto_archive from within the nandroid.sh file in the backups folder if you wish. However, the problem here is currently, moving from backup to archive on the internal sd is instant. Changing to external would take a while to move the 3GB or whatever your backup is.
Of course then you have that backup twice too.
Sionvce I bought secure settings pro just to do this, I will probably keep this task too. However, since I have foldersync app syncing my sd card to my NAS anyway, I probably dont need the autobackup.
Anyway zip attached. Enjoy
