#include <util/delay.h>
#include <avr/sleep.h>
#include <avr/power.h>
#include <avr/wdt.h>

#define POWER_PIN 3

volatile int f_wdt = 1;
int counter = 0;

void setup(void) {
watchdogOn();

DDRB |= 3 << POWER_PIN;

ADCSRA &= ~(1<<ADEN);
ACSR = (1<<ACD);
}

void loop(void) {
goToSleep(); 

counter++;

if (counter == 150) { //20 минут

   PORTB |= 3 << POWER_PIN;
    _delay_ms(500);
     
   PORTB &= ~(3 << POWER_PIN);
      
       counter = 0;
}

}

void goToSleep()   
{

set_sleep_mode(SLEEP_MODE_PWR_DOWN);
sleep_enable();
sleep_mode();


sleep_disable();
                     
}

void watchdogOn() {
  
  WDTCR |= (1<<WDP3 )|(0<<WDP2 )|(0<<WDP1)|(1<<WDP0); // 8s
  WDTCR |= (1<<WDTIE);
  sei(); // Enable global interrupts
  
}

ISR(WDT_vect)

{
f_wdt = 1;
}