Hmmm... Bluetooth might be a good one, have a bluetooth dongle in each room that syncs to your phone.. bluetooth has a very short range.
Another idea if your the only one in the home you could use a laser tripwire at the entrance of each room (ir light rather than a laser)
Another idea if your the only one in the home you could use a laser tripwire at the entrance of each room (ir light rather than a laser)