Hi ALL, need all the help and suggestions I can get. Looking for a device I can make or buy, I thought maybe oscillator circuit.Need to transmit and recieve 60 miles away.
You need an interface that detects the door has opened, and instructs the mobile phone to send a text message. Mobile phones usually have an interface port on them that you can connect to, in order to make them do things like this. The interface needs a micro-controller that needs programming in order to do all the work, and supply the message to the phone.
It's not terribly trivial, and depends entirely on the specific phone, Nokia ones seem to be most popular for this. There have been projects in various electronics magazines about doing it.
This is not going to be inexpensive. I've seen cellular modules available at Sparkfun and they're ~$100 IIRC. That's not to mention the monthly cell service fee you'll have to buy from a cellular carrier.
But that's really putting the cart before the horse. You can't do anything without some sort of renewable power source. I'm guessing we're talking about solar or wind power stored in batteries at this point, but you tell us. Is it windy out there? Is it sunny?
If you're worried about vandals entering the cabin, consider the possibility that they'll steal/destroy/disable your $500 (or whatever) sensor.