PC to Thermostat Interface Idea
 

Theres a strange but mostly useful idea i've had that involves making a digital thermostat interface with a PC through USB or even serial. Ideally the thermostat would be able to interface with the PC and display temperatures on the PC and even send an e-mail alert if the temperature reaches a certain degree. The snag in all of this planning is that i know little to nothing about making things of this nature. A good friend of mine however does. My question now is this: Is this something thats even possible to do, and if so, does anyone have any ideas for making it?

Newer motherboards have at least two thermal sensors on board. One directily under the CPU, and one somewhere else on the motherboard. Fan speeds and various system voltages are also usualy available.

Dump of data from my system:

If you're using windows, check out motherboard monitor to read these sensors.

As to actualy making one of these, the cheap and easy way to do it is to use the joystick port, because it can be hooked directly to a thermisistor.

There are companies that sell USB interface devices for your computer. For about $50 you can get an interface with up to 8 digital I/O ports and sample code for C++ and VB.

You can place a thermal sensor on one of the channels and some relays on the others.
Short answer is yes, it is possible.

Did people forget there's a computer forum?

Thermal sensors spit out analog data, though, and that has to be digitized for the computer to deal with it.

woops, mis-type.

I meant 4 analog and 4 digital I/O. I'll see if I can find a link.

as i re-read this, i realize i was fairly vague... ideally this is an external unit for use in a server rack that will report to one of the servers in each of the 6 racks and e-mail one of us if that rack gets too hot. I have seen the $50 units, i was just wondering if there was a cheaper or better solution. And a link to them would be very much appeciated scorpion.

Well, you could hook a thermisistor up to the x axis pins on a joystick port, then calibrate it, and use the x position the joystick is giving to calculate the tempature.

I said this in a previous post, but i thought I'd make it more clear.

If this was more of a computer question I would agree, however working with a Thermister analog / digital information is more of an electronic question. The hard part of what he is asking is the circuit design, then the computer.

Yes, this is possible on many different fronts, just the question is, how indepth do you want to go with designing electric circuits and then programming the interface protocol to communicate with it and then the application to communicate to your device. If you don't think you are up to all of that then the $50 solution sounds the best to me.