I've started work on a dog GPS prototype, but don't have anything to show yet. The idea is to transmit the dog GPS location to OpenHAB, and have OpenHAB evaluate the coordinates. If the coordinates are outside the yard, then play an audio alarm inside the house to let the people know the dog has wondered off.
I'd also like to do some physical computing by using an arrow mounted on a 360 servo to point to the direction of the dog. This "dog pointer" would let you know the direction the dog went when the alarm goes off, just just give you more awareness of where the dog is. The portable hand-held unit won't be part of the Forget-Me-Not competition, because I won't get to it before the end of the design challenge. But I'll do a blog post on it when it's complete anyways.
I got the dog collar box. The box itself is $20, so adding in the electronics it'll be about $48. It's breaking my self-imposed $20 limit for home automation field devices, but I guess this will have to be an exception. The box has room for 4xAA batteries, enough to power the GPS unit, microcontroller, and wireless transceiver for over 10 hours I think.
So far, I have a bread board prototype of the GPS module and transmitter working. Have to work on miniaturizing it.
It occurred to me that I could use the EnOcean sensor to do somewhat the same thing. Use the temperature sensor transmission as an indicator that the unit is within range, and if I stop getting transmissions, it means the unit is out of range. I'm limited by the transmission distance of the EnOcean sensor rather than being able to customize alarming based on GPS location, but it might be a quick and dirty way of getting the alarming function.