I 've been wanting to do this for as long as I had a computer (more than 10 years). It always seemed such an amazing idea to monitor room and outside temperatures from my computer, log them, calculate averages, make graphs etc. Until recently this was only possible combining DIY electronics which is not option for me since I solder worst than Yoko Ono sings. Also the DIY solutions where LPT, not compatible with most laptops, and provided only raw numeric outputs, not a nice program to log, do graphs etc.

All other options where high end lab equipment, with enormous cost, and requiring dedicated lab computers. So the project got postponed indefinitely until 2 weeks ago, that I found this listing on ebay, a devive called USB Thermometer, or more correctly USB HID TEMPer for $5.88.

Its manufactured by a Chinese company called RDing, and seems they have been developing similar devices for a while, but not many of them reached Europe or United States.

They have a wide range (wich can be found here but with much higher prices than the ones found on ebay) of USB thermometers and hygrometers, with different measuring ranges and features. Most of them require drivers since they create virtual COM ports to communicate with the temperature reading/logging programs.

But the one we 'll be talking about requires no drivers, since it uses USB HID (the same protocol used by USB mice and keyboards to communicate with computers) to communicate with the computer. It just requires a compatible temperature reading program.

The package arrived in 10 days, containing the USB thermometer itself, a 0.8m USB extension and a mini CDR with temperature reading programs. The included programs are ugly, slow, and not really functional, so I immediately started looking for a documentation of the API and functions so I could develop a program myself, until i stumbled into UTAC.

UTAC is a great free 3rd party program, that does monitoring, logging, and many other things the original app doesn't.

Except from the obvious monitoring and logging, it provides: Graphs, Webserver with graphs, XML webserver (Super useful for integrating into other apps and services), FTP upload, email notifications and more. It's easy to configure, and compatible with Win7 x64.

It's way better than the bundled software, and seems like the only reasonable choice for now.

Screenshots the program itself, and the web interface:

So in a bombshell, all you need is the USB thermometer that costs $5.88, a USB extension probably longer than the included (I use a 5m extension), and the free UTAC program.

Total cost: less than 10€

Result: Endless possibilities and lots of nerdy fun.