I come from an Arduino myself, and moved over to Fez a couple months ago thanks to the great GHI support. So if you ask me, go for the Fez boards.
You don’t need a Fez/Arduino for every sensor. The remote sensors are made with just an XBee module and a sensor (evt a breakout board) and power supply. Only the remote end (XBee connected to Fez) needs to be programmed.
So the remote sensor will be constructed with an XBee module, temp sensor and power supply. The receiving part can be done Various ways:
[li]XBee module, XBee adapter, temp sensor --> Fez, XBee expansion --> pc (Fez and pc needs programming)[/li]
[li]XBee module, XBee adapter, temp sensor --> pc, XBee explorer (pc needs programming)[/li]
[li]XBee module, XBee adapter, temp sensor --> Fez, XBee expansion --> Network --> pc (Fez and pc needs programming)[/li]
(see attached image)
In all cases you have to set some settings on the sending XBee modules like how often does it need to report the temperature.
No, just limited by space ;D
on fez side you need: http://www.tinyclr.com/hardware/12/fez-cobra/#/grid/item/21/
Remote sensors: http://www.sparkfun.com/products/8276 or http://www.sparkfun.com/products/9132
If you go XBee --> pc then you need: http://www.sparkfun.com/products/8687