How can I sense the movement of my two cats throughout my house, easily and cheaply?
I want to be able to detect where my two cats are within my house using an Arduino and some sensors. Accuracy doesn't need to be 100%, as long as I know which room they are in or which side of a room, that will do.
I thought of using RFID tags and readers, but I would need one reader per room or area and they are very expensive. XBEE triangulation is a possibility, but this also sounds expensive and not sure of teh size of the devices the cats need to carry,
I then thought maybe an IR lamp on the collar and a sensor in the room, but this requires a lot of power meaning a bulky pack on the collar, which I don't want.
Final idea is maybe one cat has an IR reflective patch on the collar and the other a UV reflective patch and an IR and UV sensor in each room that sends out a flash of IR and UV every 10 seconds or so. But not sure if this is safe and if it can be done.
So..... I'm looking for ideas from the community.
It must not cost a lot. The cats mustn't need to carry anything bulky. The devices need to be wireless.
Any ideas please?