Telegram Bot: Control ESP32/ESP8266 GPIO Outputs from Anywhere

This guide shows how to control the ESP32 or ESP8266 NodeMCU GPIOs from anywhere in the world using Telegram. As an example, we’ll control an LED, but you can control any other output. You just need to send a message to your Telegram Bot to set your outputs HIGH or LOW. The ESP boards will be programmed using Arduino IDE.
Project Overview
In this tutorial we’ll build a simple project that allows you to control ESP32 or ESP8266 NodeMCU GPIOs using Telegram. You can also
control a relay module
You’ll create a Telegram bot for your ESP32/ESP8266 board;
You can start a chat with the bot;
When you send the message
/led_on
to the bot, the ESP board receives the message and turns GPIO 2 on;
Similarly, when you send the message
/led_off
, it turns GPIO 2 off;
Additionally, you can also send the message
/state
to request the current GPIO state. When the ESP receives that message, the bot responds with the current GPIO state;
You can send the
/start
message to receive a welcome message with the commands to control the board.
This is a simple project, but shows how you can use Telegram in your IoT and Home Automation projects. The idea is to apply the concepts learned in your own projects.
Introducing Telegram
Messenger is a cloud-based instant messaging and voice over IP service. You can easily install it in your smartphone (Android and iPhone) or computer (PC, Mac and Linux). It is free and without any ads. Telegram allows you to create bots that you can interact with.
“
Bots are third-party applications that run inside Telegram. Users can interact with bots by sending them messages, commands and inline requests. You control your bots using HTTPS requests to Telegram Bot API
“.
The ESP32/ESP8266 will interact with the Telegram bot to receive and handle the messages, and send responses. In this tutorial you’ll learn how to use Telegram to send messages to your bot to control the ESP outputs from anywhere (you just need Telegram and access to the internet).
Creating a Telegram Bot
Go to Google Play or App Store, download and install
Open Telegram and follow the next steps to create a Telegram Bot. First, search for “
botfather
” and click the BotFather as shown below. Or open this link
in your smartphone.
The following window should open and you’ll be prompted to click the
start
button.
Type
/newbot
and follow the instructions to create your bot. Give it a name and username.
If your bot is successfully created, you’ll receive a message with a link to access the bot and the
bot token
. Save the bot token because you’ll need it so that the ESP32/ESP8266 can interact with the bot.
Get Your Telegram User ID
Anyone that knows your bot username can interact with it. To make sure that we ignore messages that are not from our Telegram account (or any authorized users), you can get your Telegram User ID. Then, when your telegram bot receives a message, the ESP can check whether the sender ID corresponds to your User ID and handle the message or ignore it.
In your Telegram account, search for “IDBot” or open this link
in your smartphone.
Start a chat with that bot and type
/getid
. You will get a reply back with your user ID. Save that
user ID
, because you’ll need it later in this tutorial.
Preparing Arduino IDE
We’ll program the
ESP32
and
ESP8266
boards using Arduino IDE, so make sure you have them installed in your Arduino IDE.
Installing the ESP32 Board in Arduino IDE (Windows, Mac OS X, Linux)
Installing ESP8266 Board in Arduino IDE (Windows, Mac OS X, Linux)
Universal Telegram Bot Library
To interact with the Telegram bot, we’ll use the
Universal Telegram Bot Library
created by Brian Lough that provides an easy interface for the Telegram Bot API.
Follow the next steps to install the latest release of the library.
Click here to download the Universal Arduino Telegram Bot library
Go to
Sketch
>
Include Library
>
Add.ZIP Library..
Add the library you’ve just downloaded.
And that’s it. The library is installed.
Important:
don’t install the library through the Arduino Library Manager because it might install a deprecated version.
For all the details about the library, take a look at the Universal Arduino Telegram Bot Library
GitHub
page.
ArduinoJson Library
You also have to install the
ArduinoJson
library. Follow the next steps to install the library.
Go to
Skech
>
Include Library
>
Manage Libraries
Search for “ArduinoJson”.
Install the library.
We’re using ArduinoJson library version 6.15.2.
Parts Required
For this example we’ll control the ESP on-board LEDs:
ESP32 board
(read
Best ESP32 dev boards
)
Alternative –
ESP8266
board (read
Best ESP8266 dev boards
)
Control Outputs using
The following code allows you to control your ESP32 or ESP8266 NodeMCU GPIOs by sending messages to a Telegram Bot. To make it work for you, you need to insert your network credentials (SSID and password), the Telegram Bot Token and your Telegram User ID.
/*

Project created using Brian Lough's Universal Telegram Bot Library: https://github.com/witnessmenow/Universal-Arduino-
Example based on the Universal Arduino Telegram Bot Library: https://github.com/witnessmenow/Universal-Arduino-
*/

#ifdef ESP32
#include <WiFi.h>
#else
#include <ESP8266WiFi.h>
#endif
#include <WiFiClientSecure.h>
#include <UniversalTelegramBot.h> // Universal Telegram Bot Library written by Brian Lough: https://github.com/witnessmenow/Universal-Arduino-
#include <ArduinoJson.h>

// Replace with your network credentials
const char* ssid = "REPLACE_WITH_YOUR_SSID";
const char* password = "REPLACE_WITH_YOUR_PASSWORD";

// Initialize Telegram BOT
#define BOTtoken "XXXXXXXXXX:XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX" // 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 "XXXXXXXXXX"

#ifdef ESP8266
X509List cert(TELEGRAM_CERTIFICATE_ROOT);
#endif

WiFiClientSecure client;
UniversalTelegramBot bot(BOTtoken, client);

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

const int ledPin = 2;
bool ledState = LOW;

// 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", "");
}
}
}
}

void setup() {
Seria