Jacky, it's sort of unclear what you're asking here; Are you a beginner or do you have experience with PICs and/or Electronics? I'm guessing that you want to be able to read a thermistor to an accuracy of 1/10 degree C, over a 0-100 degrees C range, and you're a beginner to PICs at least? For this list, I'll pick the 16F84, first off - This's not the Stamp list OK, then for 0-100C at 0.1 degree you want a reading of at least 0-1000 from your A/D conversion and some processing, which means you want a 9+ bit A/D reading (assuming the thermistor was linear, which it assuredly is NOT, so you're going to have to do some extra work, and you may be able to get by with 9 bits but don't count on it - I'd bet more like 12-14 bit A/D. Others are more expert here, I'll jsut say that it's do-able but not a one day project ); How do you plan to handle wiring the thermistor up to your PIC? How will you get around the self-heating problem with the thermistor? Will you switch in different precision resistors to scale the temperature readings, for better accuracy? (Probably a good plan. HexFET to ground from each, all common at the thermistor & PIC pin, other side of the thermistor to it's own precision voltage source perhaps, or to a cap with a series resistor to at least isolate spikes off the thermistor readings.) How will you handle calibration of your precision voltage source (voltage divider to a PIC pin(s))? Helps to test your A/D code Next: How will you handle calibration of your thermistor to that level of accuracy? How much money do you expect to spend, say a couple hundred dollars or so, to get that accuracy? Or is the 0.1 degree C spec a nicety, and if so, what accuracy do you really need? Finally, you have a temperature, now what do you do with it - Serial link to a PC? Log it to an SEEPRom? You probably know, we list members don't There are, fortunately, a lot of good projects to look at to help if you're a beginner (start at http://www.piclist.com/, http://www.dontronics.com/piclinks.html has a bunch of good links, so does http://www.new-elect.com/links.htm. You might look at the Stamp links if a total beginner; there may be a "read thermistor" bit of Stamp code out there, too, I've never bought a Stamp (they're fairly expensive compared to the 16C622's I first bought when getting into PICs.) Bet you'll have to work on it to get 0.1C accuracy, of course. I'l suggest you start by searching on piclist.com and the piclist archives (look on piclist.com), for "sigma delta" (a good way to do A/D, if a little unclear at first, it grows on you) and for thermistor, those two search terms should get you more information. There also are some temperature sensor chips out there, typically only 1 degree C accuracy though. Also, you will want to be able to program the 'F84 once you have your code; There are a good number of different programmers out there. Mark Jacky Joulin wrote: > Hello, > I research soft (and hard ) for read termistor temperature 0 to 100 0C > Termistor CTN 10K at 250C > Risolution 1/10 0C > Hard for PIC 16F84 or Stamp BS2 or ??? > > tank for your help > > Weslay@Aol.com -- I re-ship for small US & overseas businesses, world-wide. (For private individuals at cost; ask.)