issue with avr watchdog

[movie_freak]

using avr watchdog

Hi,

I've tried something like this:

Code:
void WATCH_DOG_INIT(void)
{
         watch_dog_F =1;
      // Start timed equence
      WDTCR |= (1<<WDCE) | (1<<WDE);
      // Set new prescaler(time-out)
      WDTCR = (1<<WDE) | (1<<WDP2) | (1<<WDP1)|(1<<WDP0) |(0<<WDCE);

}


void RSET_WATCH_DOG(void)
{
  wdt_reset();            // reset watch dog
  watch_dog_counter = 10;
}


ISR()          // 1ms isr
{
  if(watch_dog_F ==1)
  {
     watch_dog_mili--;
     if(watch_dog_mili==0)
       {
       watch_dog_mili=1500;
      if(watch_dog_counter > 0)
       {
            watch_dog_counter--;
            wdt_reset();
       }
      
       }

   }   
}


int main(void)
 {
      WATCH_DOG_INIT();
       
      while(1)
       {
       
            /* Some work done over here */

           RSET_WATCH_DOG();
       }

     

 }

What i am trying to do:
initial values of watch_dog_mili =1500; watch_dog_F =0;watch_dog_counter=10;

set the watchdog timeout to ~ 2secs
calling wdt_reset every 1500ms in interrupt
In the mean time calling RST_WATCH_DOG() in main to check the software hang in every 10*1500 =15secs..

In my code there are no routines which take more than 10secs..still the watchdog resets the controller as soon as it is initialized..

So need help in this regard

Surya

 

[movie_freak]

avr watchdog

Hi guys,

Now my watchdog is working fine..

The change I made is

Code:
void WATCH_DOG_INIT()
{
      wdt_enable(WDTO_2S);
   watch_dog_F =1;   

}

instead of

Code:
void WATCH_DOG_INIT(void)
{
         watch_dog_F =1;
      // Start timed equence
      WDTCR |= (1<<WDCE) | (1<<WDE);
      // Set new prescaler(time-out)
      WDTCR = (1<<WDE) | (1<<WDP2) | (1<<WDP1)|(1<<WDP0) |(0<<WDCE);

}

So i believe that i've done the initialization wrong..
Can any one tell me the mistake that i have done in the latter case??


Many Thanks,
Surya