Eng4444 please understand that folks don't sit next to their terminals all day long waiting to answer your questions. I might glance at it once a day if I'm at my desk - sometimes more, or I might not for several days at a time... Time may be of the essence for you but I also have other priorities in my life...

If you are calculating Energy = Power . Time, then you are about to open up a whole heap of time calculation problems if you are going to read the time and date, because as you move through midnight into the next day, or increment through into the next month, you have to take into account a whole new set of figures...

Example... What is the elapsed time between 14:37:31 on 25/02/06 and 17:11:09 on 26/05/06? That's a whole heap of code to do that. You have to work out how much time elapsed until midnight on one day, and how much time elapsed since midnight on the next. Then a month goes by... and you have to take account how many days have elaspsed. And was this year a Leap Year? If you get it wrong you're a day out... So unless you convert everything to Linear Time (there was a long thread on Julian Date calculation some time ago) you have a headache with a PIC full of lots of code doing no more than calculating an elapsed period.

The DS1307 however provides you with an easier solution that saves you having to do these Time and Date calculations... just count Seconds. Set up the DS1307 to output a Second Pulse to your PIC, and your program sits there doing whatever you want it to do and just simply incrementing a counter every time a Second ticks by.

Melanie