On 1 Dec 2007 at 15:52, Dharmesh Joshi wrote:
From: "Dharmesh Joshi" <[EMAIL PROTECTED]>
To: <avr-chat@nongnu.org>
Date sent: Sat, 1 Dec 2007 15:52:04 -0000
Subject: [avr-chat] Re:
> Hi Guys
>
> The AVR has in built timers, are there any samples code or website showing
> how to use them. I am very interested in using them as a calendar, and
> passing there varaible to my program and also changing the calander when
> nessary.
>
If you want time and calender functions, then you should use a RTC (Real Time
Clock).
Some of the AVRs do have the functionality to enable one to add a "watch
crystal" which is a
32.768kHz crystal which is often used to provide the clock for RTC functions.
It is simpler to use a dedicated RTC device.
Below is a routine for calculating the weekday from a specific date:
/********************************************************************\
* Calculate Day of the week
* 0 -> SUN
* 6 -> SAT
\********************************************************************/
unsigned char GregorianWeekDay(unsigned short year, unsigned char month,
unsigned char
day)
{
int a,y,m,d;
a = (14 - month) / 12;
y = year - a;
m = month + 12*a - 2;
d = (day + y + y/4 - y/100 + y/400 + (31*m)/12) % 7;
return((unsigned char)d);
}
Regards
Anton Erasmus
--
A J Erasmus
_______________________________________________
AVR-chat mailing list
AVR-chat@nongnu.org
http://lists.nongnu.org/mailman/listinfo/avr-chat
