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



int ledPin = 13;            // LED connected to digital pin 13
int sleepPin = 12;          // active LOW, ground this pin momentary to sleep
int interruptPin = 10;      // LED to show the action of a interrupt
int wakePin = 2;            // active LOW, ground this pin momentary to wake up
int sleepStatus = 0;        // variable to store a request for sleep


ISR(TIMER1_OVF_vect)
{
 Serial.println("------------timer1 overflow------------");
}

void setup()
{
  Serial.begin(9600);
  pinMode(ledPin, OUTPUT);         // sets the digital pin as output
  pinMode(interruptPin, OUTPUT);   //
  pinMode(sleepPin, INPUT_PULLUP);        // sets the digital pin as input
  pinMode(wakePin, INPUT_PULLUP);
  attachInterrupt(0, wakeUpNow, LOW); // use interrupt 0 (pin 2) and run function
   /* Normal timer operation.*/
  TCCR1A = 0x00;
  TCNT1=0x0000;
  TCCR1B = 0x05;
  TIMSK1=0x01;
}



void sleepNow()         // here we put the arduino to sleep
{

  set_sleep_mode(SLEEP_MODE_PWR_DOWN);   // sleep mode is set here
  sleep_enable();              // enables the sleep bit in the mcucr register
  power_timer1_enable();
  attachInterrupt(0, wakeUpNow, LOW); // use interrupt 0 (pin 2) and run function
  // wakeUpNow when pin 2 gets LOW
  sleep_mode();                // here the device is actually put to sleep!!

  sleep_disable();             // first thing after waking from sleep:
  // disable sleep...
  detachInterrupt(0);          // disables interrupt 0 on pin 2 so the
  // wakeUpNow code will not be executed
  // during normal running time.
  delay(1000);                 // wat 2 sec. so humans can notice the
  // interrupt.
  // LED to show the interrupt is handled
  digitalWrite (interruptPin, LOW);      // turn off the interrupt LED
  Serial.println("----------desligou o led------");

}



void wakeUpNow()        // here the interrupt is handled after wakeup
{
  //execute code here after wake-up before returning to the loop() function
  // timers and code using timers (serial.print and more...) will not work here.
  digitalWrite(interruptPin, HIGH);
  Serial.println("----------ligou o led-------");
}




void loop()
{
  digitalWrite(ledPin, HIGH);            // sets the LED on
  delay(1000);                           // waits for a second
  digitalWrite(ledPin, LOW);             // sets the LED off
  delay(1000);                           // waits for a second
  sleepStatus = digitalRead(sleepPin);   // read sleep pin here. only active
  //when blink led is off.
  if (sleepStatus == LOW) {            // start to put the device in sleep
    sleepNow();                      // sleep function called here
  }
}