DIY Thermal Probes

Hello, all. This doesn't have much to do with OC, but hopefully y'all can point me in the right direction here.

I'm in attempt to design & build a system which would utilize temperature probes to transmit data into a computer program of some sort. I don't know much about it at all, but I was thinking going through the serial port wouldn't be a bad idea.

The end idea is to have 2-5 probes connected into a single computer, writing a data table up. This isn't for me, and it's non-profit, so cheap would be good. I can solder, see, and (sort of) program.

Does anyone know of anything like this? A resource, or someone who's done it before?

TIA, guys,
lex

I havent done it before but maybe you could contact a company called "Gemini" who produce a set of products called "TingTags" these a thermal probes that connect to the computer via RS-232 (Serial) they *might* but possibly not be able to provide you with schematics, they provide data logging software with their products, you would need to code this yourself possibly unless you could tell MBM what your sensor is so this could log it

I appreciate the response, CCW, but with a deal of googleing I've come up with this:

http://www.geocities.com/CapeCanaveral/Launchpad/3632/pc_therm.htm

Seems good to me! Though I think I'm going to need plenty of help on it...

Anyway, thanks

I havn't tried it yet (parts on order), but there is an inexpensive Radio Shack multimeter with serial output and corresponding software for your PC. When you add a thermocouple module to this meter, you can connect k type thermocouples. This allows you to record temperature variations over time on your PC. I haven't played with the software enough to know the "ins and outs," but for about $100 US you would have a functional setup.

mbm gives out temps that arnt 100% accurate..they did testings of asus and abit mobos..with like .something ambient temps..and same cooling and everything and there were 12°C temps in each of the mbm's temps that it displayed..so i dont think mbm would be a good idea to check temps.

You could also use the gameport to measure temps. Not 100% accurate, but good enough. And there is no chips to get, no difficult soldering.

After all, a normal analog joystick is just two 100k pot.meters. And substitute that for a 100k thermistor, done! Can handle up to 4 sensors, software allready available. Google for gptemp or gameport+temp and you should find all you need.

I think the gameport sounds like a good solution, since you're not too experienced and on a tight budget.
If you feel a bit more adventurous, but still want to go cheap, I suggest using a microcontroller such as a PIC or a HC08. You need to have an idea about electronics and assembly languages, but by no means do you have to be an expert. For example the Motorola HC908JK8 microprocessor has 10 built-in ad converters (meaning up to ten probes) and built-in serial interface. Rom and ram is also built-in on the same chip, so it's almost ridicously easy to use. (For programming the rom, or actually flash, you use some development utilities that, you guessed it, are also on the chip.)
The components you'll need is apart from the temperature probes and the controller a level-shifter for the serial interface. RS232 uses -12V/+12V, whereas the HC08 (and just about all other microcontrollers) uses 0V/5V. There are ready-made IC's that can do this, for example the MAX 232.
All components needed will cost you about a fiver and all tools needed are free. (Is that within your budget?). You can program it using C or assembly. Without giving it too much thought the things you need are 2 16 pin chips (the cpu and the level-shifter), 6-7 capacitors, a couple of resistors and a pair of diodes. And of course yor temperature probes, which could be as simple as just an NTC thermistor.

I would say that apart from using the gameport, a HC08 is probably the cheapest and easiest solution for you. (Besides, telling someone that you built a computer is much more impressive than telling someone that you connected two thermistors to the gameport...)

Should you decide to give it a try, I'll be happy to help you getting started.

(Judging from some of my other postings, you can tell I really like these little fellows...)