Code for ESP8266 "smart" door bell

telegram_doorbell.ino

#ifdef ARDUINO_ARCH_ESP8266
#include <ESP8266WiFi.h>
#endif
#ifdef ARDUINO_ARCH_ESP32
#include <WiFi.h>
#endif

#include <esp8266-google-home-notifier.h>
#include <ESP8266HTTPClient.h>

const char* ssid = "WiFi_network";
const char* password = "WiFi_pass";

const int buttonPin = 15;    // D8 is "15" 

/*
  D0/GPIO16 can not be used as input as it's connected to the RESET: pulling it low causes a reset of the processor (which is why you see the LED blink).
  The ADC has a voltage divider attached to it, so its range is 0-3.3V rather than the 0-1.06V the ESP8266 normally has. This divider may mess up an analog signal that itself is also based on a voltage divider!
  D4/GPIO2 is connected to the internal LED (which is lit when the pin is LOW).
  D9/GPIO3 is TX (Serial).
  D10/GPIO1 is RX (Serial).
*/

const int ledPin = 2;  // D4 is "2"
const int resetPin = 16;  // D0 is "16"

GoogleHomeNotifier ghn;
const char displayName[] = "Name of your Google Home speaker" // for example, "Bedroom speaker";

void resetFunc () {
  Serial.println("Self-resetting...");
  WiFi.forceSleepBegin();
  delay(100);  
  ESP.restart(); // To restart the ESP8266, we need to call the restart method on the ESP extern variable, which is an object of class EspClass
  delay(1000);  
  digitalWrite(0, HIGH);
  digitalWrite(resetPin, LOW);
  ESP.reset(); // If above didn't help... 
}

void setup () {
  pinMode(buttonPin, INPUT);
  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, LOW);

  Serial.begin(115200);
  Serial.println("");

  WiFi.begin(ssid, password);
  WiFi.hostname("esp8266_doorbell");

  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting..");
  }

  Serial.print("Connected to [");
  Serial.print(ssid);
  Serial.println("] access point.");
  // power();
}

void loop() {
  if (digitalRead(buttonPin) == HIGH) {
    Serial.println("Ding!");
    digitalWrite(ledPin, LOW);
    bell();
  }
  digitalWrite(ledPin, HIGH);

  if (WiFi.status() != WL_CONNECTED) {
    Serial.println("No WiFi connection!");
    resetFunc();
  } else {
    // Serial.println("Connected.");
  }
}

void bell() {
  digitalWrite(ledPin, LOW);

  if (WiFi.status() == WL_CONNECTED) { //Check WiFi connection status
    HTTPClient http;  //Declare an object of class HTTPClient
    http.begin("http://example.com/doorbell-rings/do/something");  //Specify request destination
    int httpCode = http.GET(); //Send the request
    Serial.println(httpCode);
    if (httpCode > 0) { //Check the returning code
      String payload = http.getString();   //Get the request response payload
      Serial.println(payload);                     //Print the response payload
    } else {
      Serial.println("No WiFi connection!");
      resetFunc();
    }
    http.end();   //Close connection
    googlehome();
  } else {
    Serial.println("No WiFi connection!");
    resetFunc();    
  }
  
  Serial.println("Idling to prevent multiple messages being sent repeatedly.");
  delay(30000);    //Send a next request only after half a minute has passed.
}

void googlehome() {

  Serial.println("connecting to Google Home...");
  if (ghn.device(displayName, "en") != true) {
    Serial.println(ghn.getLastError());
    return;
  }
  Serial.print("found Google Home(");
  Serial.print(ghn.getIPAddress());
  Serial.print(":");
  Serial.print(ghn.getPort());
  Serial.println(")");
  
  if (ghn.notify("Hey! Someone is ringing the door bell!") != true) {
    Serial.println(ghn.getLastError());
    return;
  }
  Serial.println("Done.");
  
}