I have a room with 30 objects which may or not be present, and I want to be able to detect which objects are in the room.
My first idea was to attach a RFID tag to each one of these objects and have a sensor detecting them, but then I have frequency collision problems and since the room is quite large, I also cannot activate tags which are further away. Or I may be missing something...
I would also want to have objects not carrying an active radio transmitter, i.e., no batteries wandering around, just RFID tags or resonant metal pieces.
I could use cameras but image processing would require an Arduino on steroids.
This is for a hobby project since I need an excuse to use my Arduino again :P
How would you solve such challenge?