You can buy sensors for things like that, but they'll tend to be expensive for what you get, eg: http://www.tequipment.net/AmprobeTR300.html http://www.tequipm

You can buy sensors for things like that, but they'll tend to be expensive for what you get, eg: http://www.tequipment.net/AmprobeTR300.html http://www.tequipment.net/AmprobeTR300.html If you like to hack around with micro-controllers then you can build something that does all that more for about the same price, but have a lot more flexibility. Google for things like "1-wire humidity sensor". The Dallas Semi 1-wire bus is widely supported with most micro controllers, and fairly easy to implement.