Arduino Nano - Sleep/Wake - Same Button

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1

Hi

I want to make Arduino Nano go to deep sleep using interrupt, Pin 2. And then wake up with same pin.

Schematic => A jumper wire connected to pin D2.
Here is the code:

#include <avr/sleep.h>
#define interruptPin 2 

unsigned long wakeUpMillis = 0;
bool IntAttached = true; // Interrupt is attached 

void setup() 
{
  Serial.begin(115200);//Start Serial Comunication
  pinMode(LED_BUILTIN,OUTPUT);
  pinMode(interruptPin,INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(interruptPin), goToSleep, LOW);
}

void loop() 
{
  digitalWrite(LED_BUILTIN,HIGH);
  delay(500);
  digitalWrite(LED_BUILTIN,LOW);
  delay(500);
  
  if (!IntAttached && millis() - wakeUpMillis > 2000)
  {
    noInterrupts();
    attachInterrupt(digitalPinToInterrupt(interruptPin), goToSleep, LOW);
    interrupts();
    IntAttached = true;
  }
}

void goToSleep()
{
  sleep_enable();//Enabling sleep mode
  noInterrupts();
  attachInterrupt(digitalPinToInterrupt(interruptPin), wakeUp, LOW);
  set_sleep_mode(SLEEP_MODE_PWR_DOWN);
  Serial.println("Going to sleep..... zzzZZZZ");
  delay(2000);
  interrupts();
  sleep_cpu();//activating sleep mode
  // Now the µController is asleep........zzzZZZZZZ
  //
  //
  // will resume from here
  //  
  //
  Serial.println("just woke up!"); 
}

void wakeUp()
{
  noInterrupts();
  detachInterrupt(digitalPinToInterrupt(2));
  interrupts();
  IntAttached = false; // Interrupt is detached.

  Serial.println("Interrupt Fired");
  sleep_disable();
  wakeUpMillis = millis();
}

The problem is that the Nano goes to sleep and wakes up immediately when D2 is LOWered.

2

" Nano goes to sleep and wakes up immediately when D2 is LoWered." That means the switch attached to pin2 is now working as a momentary switch. But you want it to work as a toggle switch, right? There are many examples for toggle switches. Usually If you apply the same concept in your code, it will give your desired result.

3

No, it is a momentary switch.
One push ---- Go to sleep
Next push --- Wake up

I have also tried to Attach the interrupt on FALLING but no results.

4

You may think you're disabling interrupts, but in reality this doesn't happen in your sketch. I think it's actually the internal watchdog on the microcontroller that re-enables them; you'd have to chekc the datasheet on this. Good thing too, because for instance your Serial.println wouldn't work if interrupts were truly disabled.

Also I think you're better off using an interrupt only for wakeup and not to go to sleep, so I'd give the fundamental logic of your code a serious thought.

Finally, consider debouncing. It's a thing!

And the other end of the wire goes to GND, I assume? Even a simple schematic can have bugs in it, it shows :wink:

5

I have tried digitalRead (with debounce) to Go to Sleep and interrupt for Wake up. But still not working.

6

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