Deep_sleep_awake_timer.ino

/*
Deep Sleep with External Wake Up
=====================================
This code displays how to use deep sleep with
an external trigger as a wake up source and how
to store data in RTC memory to use it over reboots

This code is under Public Domain License.

Hardware Connections
======================
Push Button to GPIO 33 pulled down with a 10K Ohm  <<----------------------------------------------------------
resistor

NOTE:
======
Only RTC IO can be used as a source for external wake
source. They are pins: 0,2,4,12-15,25-27,32-39.   <<-----------------------------------------------------------

Author:
Pranav Cherukupalli <cherukupallip@gmail.com>

 Reference article:  https://randomnerdtutorials.com/esp32-external-wake-up-deep-sleep/
*/

#include <WiFi.h>
#include "driver/adc.h"
#include <esp_wifi.h>
#include <esp_bt.h>

#define BUTTON_PIN_BITMASK 0x200000000 // 2^33 in hex   --See reference article.

float currentMillis, startMillis, elapsed;

// How many minutes the ESP should be awake
#define AWAKE_TIME 1 //Minutes

const unsigned long period = (AWAKE_TIME * 60L * 1000L); //the value is a number of milliseconds in 15 Minutes.
//const unsigned long period = 60000; //the value is a number of milliseconds in 5 seconds

#define SLEEP_LED  26  //LED is off in deep sleep

RTC_DATA_ATTR int bootCount = 0;

void print_wakeup_reason() {
  esp_sleep_wakeup_cause_t wakeup_reason;

  wakeup_reason = esp_sleep_get_wakeup_cause();

  switch (wakeup_reason)
  {
    case ESP_SLEEP_WAKEUP_EXT0 : Serial.println("Wakeup caused by external signal using RTC_IO"); break;
    case ESP_SLEEP_WAKEUP_EXT1 : Serial.println("Wakeup caused by external signal using RTC_CNTL"); break;
    case ESP_SLEEP_WAKEUP_TIMER : Serial.println("Wakeup caused by timer"); break;
    case ESP_SLEEP_WAKEUP_TOUCHPAD : Serial.println("Wakeup caused by touchpad"); break;
    case ESP_SLEEP_WAKEUP_ULP : Serial.println("Wakeup caused by ULP program"); break;
    default : Serial.printf("Wakeup was not caused by deep sleep: %d\n\n", wakeup_reason); break;
  }
}

 
  void setup(){
  
  Serial.begin(115200);
  while(!Serial){};
  
  startMillis = millis();  //initial start time

  //Print the wakeup reason for ESP32
  print_wakeup_reason();

  //Increment boot number and print it every reboot
  ++bootCount;
  Serial.println("Boot number: " + String(bootCount));
  
  /*
  First we configure the wake up source
  We set our ESP32 to wake up for an external trigger.
  There are two types for ESP32, ext0 and ext1 .
  ext0 uses RTC_IO to wakeup thus requires RTC peripherals
  to be on while ext1 uses RTC Controller so doesnt need
  peripherals to be powered on.
  Note that using internal pullups/pulldowns also requires
  RTC peripherals to be turned on.
  */
  esp_sleep_enable_ext0_wakeup(GPIO_NUM_33,1); //1 = High, 0 = Low
  
  pinMode(SLEEP_LED,OUTPUT);
  
  digitalWrite(SLEEP_LED,HIGH);  //SLEEP_LED will be Off in deep sleep

}

void loop(){

  currentMillis = millis();  //get the current "time" (actually the number of milliseconds since the program started)
  
  if (currentMillis - startMillis >= period)  //test whether the period has elapsed
  {

    elapsed = currentMillis - startMillis;
    Serial.print(" Minutes:  ");
    Serial.print(((elapsed/1000)/60), 1);
    Serial.println("  Awake time");
    Serial.println(""); 

    Serial.println("Going to Deep Sleep");

    gotoDeepSleep();
  }

}

void gotoDeepSleep()
{

  //Serial.println("Going to sleep...");
  WiFi.disconnect(true);
  WiFi.mode(WIFI_OFF);
  btStop();

  adc_power_off();  //turn off adc
  esp_wifi_stop();  //turn off wifi
  esp_bt_controller_disable();  //turn off bluetooth

  // Goto deep sleep
  esp_deep_sleep_start();

}