bot.ino

/*
  Rui Santos
  Complete project details at https://RandomNerdTutorials.com/telegram-control-esp32-esp8266-nodemcu-outputs/
  
  Project created using Brian Lough's Universal Telegram Bot Library: https://github.com/witnessmenow/Universal-Arduino-Telegram-Bot
  Example based on the Universal Arduino Telegram Bot Library: https://github.com/witnessmenow/Universal-Arduino-Telegram-Bot/blob/master/examples/ESP8266/FlashLED/FlashLED.ino
*/
#include <WiFi.h>
#include <WiFiClientSecure.h>
#include <UniversalTelegramBot.h>   // Universal Telegram Bot Library written by Brian Lough: https://github.com/witnessmenow/Universal-Arduino-Telegram-Bot
#include <ArduinoJson.h>

// Replace with your network credentials
const char* ssid = "wifi";
const char* password = "pass";

// Initialize Telegram BOT
#define BOTtoken "xxxxxxxxxx:xxxxxxxxxxxxxxxxxxxxxxxxx-xxx-xxxxx"  // your Bot Token (Get from Botfather)

// Use @myidbot to find out the chat ID of an individual or a group
// Also note that you need to click "start" on a bot before it can
// message you
#define CHAT_ID "xxxxxxxxx"

WiFiClientSecure client;
UniversalTelegramBot bot(BOTtoken, client);

// Checks for new messages every 1 second.
int botRequestDelay = 1000;
unsigned long lastTimeBotRan;

const int ledPin = 32;
bool ledState = LOW;

void setup() {
  Serial.begin(115200);

  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, ledState);
  
  // Connect to Wi-Fi
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  client.setCACert(TELEGRAM_CERTIFICATE_ROOT); // Add root certificate for api.telegram.org

  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi..");
  }
  // Print ESP32 Local IP Address
  Serial.println(WiFi.localIP());

  Serial.print("Retrieving time: ");
  configTime(0, 0, "pool.ntp.org"); // get UTC time via NTP
  time_t now = time(nullptr);
  while (now < 24 * 3600)
  {
    Serial.print(".");
    delay(100);
    now = time(nullptr);
  }
  Serial.println("\n");
  Serial.println(now);

  bot.sendMessage(CHAT_ID, "Welcome! type /start to start", "");
}

void loop() {
  handleTelegramBot();
}

// Handle Telegram bot logic
void handleTelegramBot() {
  if (millis() > lastTimeBotRan + botRequestDelay)  {
      int numNewMessages = bot.getUpdates(bot.last_message_received + 1);
      Serial.println("BOT: got " + String(numNewMessages) + " messages");

      while(numNewMessages) {
        Serial.println("BOT: got response");
        handleNewMessages(numNewMessages);
        numNewMessages = bot.getUpdates(bot.last_message_received + 1);
      }
      lastTimeBotRan = millis();
    }
}

// Handle what happens when you receive new messages
void handleNewMessages(int numNewMessages) {
  Serial.println("handleNewMessages");
  Serial.println(String(numNewMessages));

  for (int i=0; i<numNewMessages; i++) {
    // Chat id of the requester
    String chat_id = String(bot.messages[i].chat_id);
    if (chat_id != CHAT_ID){
      bot.sendMessage(chat_id, "Unauthorized user", "");
      continue;
    }
    
    // Print the received message
    String text = bot.messages[i].text;
    Serial.println(text);

    String from_name = bot.messages[i].from_name;

    if (text == "/start") {
      String welcome = "Welcome, " + from_name + ".\n";
      welcome += "Use the following commands to control your outputs.\n\n";
      welcome += "/led_on to turn GPIO ON \n";
      welcome += "/led_off to turn GPIO OFF \n";
      welcome += "/state to request current GPIO state \n";
      bot.sendMessage(chat_id, welcome, "");
    }

    if (text == "/led_on") {
      bot.sendMessage(chat_id, "LED state set to ON", "");
      ledState = HIGH;
      digitalWrite(ledPin, ledState);
    }
    
    if (text == "/led_off") {
      bot.sendMessage(chat_id, "LED state set to OFF", "");
      ledState = LOW;
      digitalWrite(ledPin, ledState);
    }
    
    if (text == "/state") {
      if (digitalRead(ledPin)){
        bot.sendMessage(chat_id, "LED is ON", "");
      }
      else{
        bot.sendMessage(chat_id, "LED is OFF", "");
      }
    }
  }
}