Hi guys, i release a new version of the code with some fixes and enhancement. New features:

• Watchdog: the system will reboot if it's stuck for more than 8 seconds (note: you have to be sure you have the last bootloader for arduino mega, older ones have a bug that causes endless reboot. You can easily flash it using another arduino and following these instructions: http://www.gammon.com.au/forum/?id=11635)
• Restore state: the system will remember its state in case of rebooting or shutting off.
• Safe mode: the system will enter in a "safe mode" in case of any failure (it will stop rebooting after 5 reboots, to avoid undesidered false alarms)
• Log php script: included in the source code, it may be put on a webserver to log you accesses
• Some memory fixes and small stuff

If you are going to use a W5100 ethernet (I finally got a working one) you have to connect pin 10 to the SS pin. Since in this project the pin 10 is used for GSM modem shield, you have to change it (maybe to pin 53, like in the scheme). You may easily do it with a small modification to the library, follow this link:

https://github.com/kiwisincebirth/Arduino/tree/master/Ethernet