First of all I would like to thank the guys at Arduino for doing a great job with their website. It is very informative. I haven't used any of the micro controllers yet and I want to point out that I am a newbie when it comes to hobby electronics. I am in 4th year at university and I am doing some research for my final project. My question is how can I implement a watchdog timer using the Arduino platform and which hardware version is the most versatile. I need it for taking in some inputs from a vehicle and Hall effect and GPS sensor and sending it through a GSM modem. Any other tips are more than welcome. Thank you guys!