AVR-Chat

Please can you also share the code snippets where you are initializing PORTD
and also the ones where you are declaring the variables being used in the
ISR?

Ranjit


On Sat, May 8, 2010 at 10:54 AM, Andrew <ajellisuk@yahoo.co.uk> wrote:

>
>
> Hi,
>
> I have a project using an Atmega16 where the timer should be interrupting
> once a second, but my sconds variable in not being incremented. If I use
> this line:
>
> PORTD = ~PORTD;
>
> The leds connected to that port flash, if I write my seconds variable to
> that port only bianry one is indicated, whcih suggests to me that the timer
> is not running or the firmware is being reset.
>
> Could someone shed some light on this for me please? I have disabled the
> watch dog timer too My code is below:
>
> Andrew
>
> const uint16_t interval = 4000000/65536;//Work out interval from CPU
> frequency
>
> void Init_Timer1()
> {
> // Set up counter. Fclk = 4Mz
> TCCR1B = 1 << WGM12 | 1 << CS12; // Fclk / 256, clear on match
> OCR1A = interval; // Timer ticks at 4000000/(256*interval) (1s)
> TIMSK |= (1 << OCIE1A | 1 << TOIE1);
> asm("sei");
> }
>
> ISR(TIMER1_COMPA_vect)
> {
> wdt_reset();
> power_save_timer++;
> seconds = seconds+1;
> PORTD = seconds << 2;// Used to verify timer is running
>
> if (seconds>59)
> {
> seconds=0;
> minutes++;
> }
>
> if(minutes>59)
> {
> minutes=0;
> hours++;
> }
>
> if(hours>23) hours=0;
> }
>
>  
>


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