Testa_Sleep.ino

#include <watchdogHandler.h>
#include <avr/power.h>
#include <avr/wdt.h>
#include <avr/sleep.h>

volatile unsigned long secondsSinceStartup = 0;
volatile unsigned long secondsLastUpdate = 0;
const unsigned long secondsUpdateFrequency = 60 * 30;
//-----------------------------------------------------
void setup(void)
{
  //  Disable the watchdog timer first thing, in case it is misconfigured
  wdt_disable();
  Serial.begin(115200);
  Serial.println("Hello!");
  //  Just cool our jets for a sec here
  delay(2000);
  //  Run ISR(WDT_vect) every second:
  setup_watchdog(WDTO_1S);

  // Valid delays:
  //   WDTO_15MS
  //  WDTO_30MS
  //  WDTO_60MS
  //  WDTO_120MS
  //  WDTO_250MS
  //  WDTO_500MS
  //  WDTO_1S
  //  WDTO_2S
  //  WDTO_4S
  //  WDTO_8S
}
//-----------------------------------------------------
void loop(void) {
  //  Has it been enough time to update?
  if ( secondsSinceStartup - secondsLastUpdate > secondsUpdateFrequency) {
    Serial.print("It's been this many seconds: ");
    Serial.println(secondsSinceStartup);
    Serial.print("and millis() says: ");
    Serial.println(millis());
  }
  //  Go to sleep forever... or until the watchdog timer fires!
  sleeping();
}
// This function will get called every time the watchdog handler fires
//-----------------------------------------------------
ISR(WDT_vect)
{
  //  Anything you use in here needs to be declared with "volatile" keyword
  //  Track the passage of time.
  secondsSinceStartup++;
}
//-----------------------------------------------------
void sleeping()
{
  //  The precise sequence of these instructions is important for the ATMEGA238
  //  SLEEP_MODE_PWR_DOWN: Disable every clock domain and timer except for the watchdog timer.
  //  Only way to wake up the device is the WDT and the external interrupt pins.
  //  The millis() timers will be disabled during sleep, which is why we track seconds in the
  //  watchdog timer routine.
  //  You could shut down your external sensors & hardware here
  set_sleep_mode(SLEEP_MODE_PWR_DOWN);
  sleep_enable();
  sei();
  sleep_cpu();
  sleep_disable();
  waking();
}
//-----------------------------------------------------
void waking()
{
  digitalWrite(13, !digitalRead(13));
}