PlatformIO_MailboxNotifierDeepSleepWiFi/src/main.cpp

#include <Arduino.h>
#include <WiFi.h>
#include <WiFiClientSecure.h>
#include <ArduinoJson.h>

#define ONBOARD_LED  2
#define uS_TO_mS_FACTOR 1000
#define BUTTON_PIN_BITMASK 0x200000000 // 2^33 in hex

RTC_RODATA_ATTR int bootCount=0;

// Wifi network credentials
const char* ssid = "JoNelsDarlings";
const char* password = "Paris2016";
esp_sleep_wakeup_cause_t wakeup_reason;

void print_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",wakeup_reason); break;
  }
}

void connect_wifi(){
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  
  while (WiFi.status() != WL_CONNECTED) {
    Serial.print(".");
    digitalWrite(ONBOARD_LED,HIGH);
    delay(100);
    digitalWrite(ONBOARD_LED,LOW);
    delay(400);
  }

  Serial.println("");
  Serial.println("WiFi connected");
  digitalWrite(ONBOARD_LED,HIGH);
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
}

void send_notification(){
  Serial.println("Sending Notification.");
  WiFiClientSecure client;
  client.setInsecure(); // NOT RECOMMENDED
  const char* host="deadswitch.kawomi.com";
  const int port=443;
  if (!client.connect(host,port)) {
    Serial.println("connection failed");

    //blink the led to indicate the failed connection.....
    for (int i=0;i<=5;i++) {
        Serial.print("!");
        digitalWrite(ONBOARD_LED,HIGH);
        delay(1000*i);
        digitalWrite(ONBOARD_LED,LOW);
        delay(100);
    }
    return;
  }

  String url = "/api/v1?topic=mailbox.livorno.address&secs=0&email=joerg.tretter@gmail.com";
  Serial.print("Requesting URL: ");
  Serial.println(url);
  client.print(String("POST ") + url + " HTTP/1.1\r\n" +
                  "Host: " + host + "\r\n" +
                  "Content-Type: application/x-www-form-urlencoded\r\n" +
                  "Content-Length: 14\r\n\r\n" +
                  "platform=esp32\r\n");

}

void setup() {
  bootCount++;
  Serial.begin(9600);
  pinMode(ONBOARD_LED,OUTPUT);

  delay(2000); // just a bit of time to start logging..
  Serial.printf("Boot #: %d\n",bootCount);
  print_wakeup_reason();

  /* if (bootCount % 2 == 0){
    digitalWrite(ONBOARD_LED,HIGH);
    delay(100);
  } else {
    digitalWrite(ONBOARD_LED,LOW);
  } */

  wakeup_reason = esp_sleep_get_wakeup_cause();

  if(wakeup_reason==ESP_SLEEP_WAKEUP_EXT0){  
    connect_wifi();
    send_notification();
  } else {
    Serial.println("Regular boot, going into deep sleep.");
  }


  //esp_sleep_enable_timer_wakeup(30000*uS_TO_mS_FACTOR);
  esp_sleep_enable_ext0_wakeup(GPIO_NUM_33,1); //1 = High, 0 = Low
  
  Serial.println("Going to sleep now");
  delay(1000);
  esp_deep_sleep_start();
}

void loop() {
  /* When dealing with deep sleep, it looks like the esp will go back into setup... */
  
/*  delay(1000);
  digitalWrite(ONBOARD_LED,HIGH);
  delay(100);
  digitalWrite(ONBOARD_LED,LOW); */
}