I'd like to put together a project for sensing the temperature of the room. I'll bet it can be done with a few inexpensive components and a bit of VB code, but I'm not sure where to start.

Here is the basic concept...

- I have a server room here at work.

- The server room has its own air conditioning unit.

- The air conditioning unit sometimes will not come back on after a power outage. The servers are on UPS's, but the air conditioner uses too much juice to put on a UPS.

- I simply need to enter the server room and press one of the buttons on the control panel to make the AC start working again.

- I have had trouble with getting the building owners to fix the AC so that it works properly. They have sent techs in, several times, to fix the problem. They have not been able to do so. And moreso, they are unable to reproduce the problem when they deliberately cut power to the AC unit.

- I have resigned myself to the fact that it's not going to get fixed, and that it's not going to get replaced either, without a serious amount of corporate red tape.

- I want to add a cheap circuit to the parallel port or serial port of one of the 24/7 computers that live in that room. The circuit would sense the ambient temperature in the room.

- I want to be able to write a VB program that will run on the computer 24/7, and give me the temperature reading. When the temperature rises above a designated threshold, it will send an email to a designated set of addresses.

Writing the VB code to send the email isn't a problem, just the part that reads the temp value will depend on whatever D-I-Y circuit is created. I've got no idea how something like that would be done.

There's a lot of temp sensors to be found in Google, but they are either very expensive integrated-web-server boxes, or they are designed to interface with an X-10 system. Either way, they're more money than I want to spend. I'm sure it could be done for ten bucks in Radio Shack parts which I'd happily pay out of my own pocket if it could make me sleep better.

Does anyone know of an existing D-I-Y project which can do this?