I live in a house with many doors and windows and I plan - as an easy project - to be able to detect and see which door/window is open using simple leds. What I do not want to do is to have 2 or 3 wires for each sensor hanging on the wall or be on the floor... so I am searching for a way to connect simple wireless window/door contacts (rf 433mhz usually) sold very cheap on ebay. Also I do not want to have 1 receiver for each transmitter because it seems foolish, power & space consuming..
XBee is a very expensive way to do this. Bluetooth could be another option. What's your opinion ?