Ouch. Commercial range typically goes to 0C Industrial to -40C Military to -55C Space is usually heated up (or cooled down!) to military and the micros are custom manufactured and tested. Sounds like you're aiming for Antarctica - lowest temperature recorded on earth (about -129F, -89C). There are lots of people who have equipment operating down there. In the case I was speaking of the heater was completely mechanical, and was meant primarily to warm up the batteries for a remotely operated telescope. It used a fossil fuel of some sort - I didn't ask any particular questions about lighting the burner. Sounds like no one on this list has any good insight for you - you may have to check with others who have gone before you and see what they do. Given that Antarctica is manned 24/7/365 now, I expect that equipment reliability is not a solved problem due to temperature and other factors. You may not yet be able to build a device that can work unattended for years without a lot more money than it's probably worth. -Adam On 1/11/08, alan smith wrote: > sorry...C like about -78C to be exact. Even if they exist...$$$$$$$$ so I dont think they want to do that > > "M. Adam Davis" wrote: C or F > > ;-D > > How far below -40? Such chips exist, but you ought to consider > specifying a lower bound. > > I can test and then send you a tube of -41 to 85C chips, if that'll > fit the bill. > > When I worked with people embedded Rabbit core modules for use in > antarctica they used heaters to bring it up to -40, then started the > micro. Don't ask me what they used to control the heaters. :-) > > -Adam > > On Jan 10, 2008 6:58 PM, alan smith wrote: > > Anyone know of a micro that is rated below 40 degrees? > > > > Might be a moot issue if the support chips won't operate that low either I suppose. > > > > > > --------------------------------- > > Looking for last minute shopping deals? Find them fast with Yahoo! Search. > > -- > > http://www.piclist.com PIC/SX FAQ & list archive > > View/change your membership options at > > http://mailman.mit.edu/mailman/listinfo/piclist > > > > > > -- > - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - > - - - - - - - - - - - - - - - - - - - - - - - - - > Moving in southeast Michigan? Buy my house: http://ubasics.com/house/ > > Interested in electronics? Check out the projects at http://ubasics.com > > Building your own house? Check out http://ubasics.com/home/ > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > > > > --------------------------------- > Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Moving in southeast Michigan? Buy my house: http://ubasics.com/house/ Interested in electronics? Check out the projects at http://ubasics.com Building your own house? Check out http://ubasics.com/home/ -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist