Thank you to everyone!
PaulS
Yes, I now whats an integer....This must be only 0 without comma. A lot of hours trying possible solutions, my brain isnt too accurate...
Good idea to put lastWriteTime, Ill try possible solutions
dannable:
I take your advice, and pylon´s too and I will buy a DS3231.
An engine room is between 25-55 degrees, and the idea is taking temperatures inside the engine room and in the inputs and outpus of air intractions and extractions....This is only the beggining of the project, I will do other measurements of other parameters.....I will post future doubts about that, Im sure that it will be any...
pylon:
I want the best precission I´ll can get.
I think that my arduinos have a crystal oscillator: I have a Mega 1280 and a Mega 2560.
As I said before, I´ll take your advices and I will buy a DS 3231.
But now my doubt is: Where do you buy your components?? I usually buy in dealextreme and eforchina and Im a few days seeking a website to buy components, ICs...where do you recommend me to buy it??
Thanks a lot for your replies