real time

hadeelqasaimeh · Joined: 05 Jan 2006 Posts: 105

hi all

i wonder if i can use timers to count one day or one month?

thank you

Ttelmah · Guest

Without extra software, no. However it is totally simple, to have a hardware timer that counts in (say), seconds, and just have an interrupt routine that itself decrements a larger counter.

Best Wishes

mskala · Joined: 06 Mar 2007 Posts: 100 Location: Massachusetts, USA

Having an interrupt routine connected to any timer overflow works fine.

Using even a decent oscillator that's rated for 50ppm, though, you could be off by 2 minutes per month, plus any rounding errors if your overflow is does not evenly go into 1 second, or whatever count time.

Of course rounding errors can be corrected easily by software, too.