wvmarle:
For the daily counter: if you have high production numbers (depending on what you produce this number could range from one car to a million matches) you can't save every time to EEPROM, while you should do just that to keep track of the numbers and to be prepared for power outage at any moment. It's rated 100,000 writes - real life numbers are probably a couple million writes, but that's it, then your EEPROM is done for.
That reminds me of something I read here:
If that is so, then you should theoretically be able to count all the way to 1,600,000 (if my math is right) using only a single 4-byte page of EEPROM. You can extend this by using additional 4-byte pages, each of which would increase the maximum possible count by 3,200,000.
However, to do that would require that you have some means of writing to the EEPROM without it being part of an erase/write cycle. The basic idea is that, once you set a page to (in binary) 11111111 11111111 11111111 11111111, then you would be able to individually set each of those 1s to 0, and by using the 0s as tally marks you could count up to 32 before needing another erase. (An EEPROM page erase sets every bit in the page to 1, not to 0 as you might expect. That's why I start from all 1 bits.)
Does the compiler provide a way of doing this?