How to wake from power down mode via both WDT and interrupt?

Projects Programming
1

Hello all!
I get trouble combining two examples of sleep/wake. I need let Atmega wakes every 4 seconds when sleeping and blink a LED, and go sleep again; and also make possible wake for some time (e.g. 45 sec). After that time it should go sleep again, and blink LED every 4 sec. In the waked mode LED should be on continuously.

Examples used as source were taken from

My sketch:

#define LEDPIN A0;

#include <avr/sleep.h>
#include <avr/power.h>
#include <avr/wdt.h>
int seconds=0;
volatile boolean f_wdt=true,
                 bActive=true;

void pin2Interrupt(void){
  detachInterrupt(0);
  digitalWrite(LEDPIN,HIGH);
  bActive=true;
}

ISR(WDT_vect){
  if(!bActive && !f_wdt) f_wdt=true;
}

void enterSleep(void){
  if(bActive){
    attachInterrupt(0, pin2Interrupt, LOW);
    digitalWrite(LEDPIN,LOW);
    bActive=false;
  }
  set_sleep_mode(SLEEP_MODE_PWR_DOWN);
  sleep_enable();
  sleep_mode();
  sleep_disable(); /* First thing to do is disable sleep. */
  power_all_enable(); // ???  - from WDT wakeup example, no such in Interrupt wakeup example
}

void setup(){
  pinMode(LEDPIN,OUTPUT);
  /* Clear the reset flag. */
  MCUSR &= ~(1<<WDRF);
  /* In order to change WDE or the prescaler, we need to
   * set WDCE (This will allow updates for 4 clock cycles).*/
  WDTCSR |= (1<<WDCE) | (1<<WDE);
  /* set new watchdog timeout prescaler value */
  WDTCSR = 1<<WDP3; /* 4.0 seconds */
  /* Enable the WDT interrupt (note no reset). */
  WDTCSR |= _BV(WDIE);
}

void loop(){
  if(f_wdt && !bActive){
    /* blink LED */
    digitalWrite(LEDPIN,HIGH);
    delay(50);
    digitalWrite(LEDPIN,LOW);
    f_wdt = false;
    enterSleep();
  }
  if(bActive){
    delay(1000);
    seconds++;
    if(seconds == 45){
      seconds = 0;
      enterSleep();
    }
  }
}

Now this wake MCU every 4 seconds and blinks LED, but won't wake up when I press button on D2 (Int0).

2

Now this wake MCU every 4 seconds and blinks LED, but won't wake up when I press button on D2 (Int0).

You don't think that it's important to mention HOW the switch is wired? I do.

3

PaulS, to ground, i. e. when I press button, there is LOW level on D2.

4

to ground, i. e. when I press button, there is LOW level on D2.

Look at your switch. Count the number of legs it has. Look at what you posted here. Count the number of connections described. Do they match? Hint: No.

What is the value of the signal to the pin when the switch is not pressed?