Hi GT, I may have caused slight confusion.  I would like to programme a weekly reboot of the Pis and a daily/36hr reboot of cgminer.  My set-up is away from home and I can't SSH into it with my USB broadband dongle.  Therefore, refreshing the devices at those intervals was my plan of running stable   I've tried /etc/rc.local and crontab -e scripts but it seems I have permission/path issues that I haven't bottomed out yet as nothing happens after a sudo reboot.