Telegram: ESP32 Motion Detection with Notifications (Arduino IDE)

This tutorial shows how to send notifications to your Telegram account when the ESP32 detects motion. As long as you have access to the internet in your smartphone, you’ll be notified no matter where you are. The ESP board will be programmed using Arduino IDE.

ESP32 PIR Motion Sensor Telegram Send Message Notification Arduino

Project Overview

This tutorial shows how to get notifications in your Telegram account when the ESP32 detects motion.

ESP32 with PIR Motion Sensor Send Message Notification to Telegram using Arduino IDE

Here’s an overview on how the project works:

  • You’ll create a Telegram bot for your ESP32.
  • The ESP32 is connected to a PIR motion sensor.
  • When the sensor detects motion, the ESP32 sends a warning message to your telegram account.
  • You’ll be notified in your telegram account whenever motion is detected.

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

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 will interact with the Telegram bot to send messages to your telegram account. Whenever motion is detected, you’ll receive a notification in your smartphone (as long as you have access to the internet).

Creating a Telegram Bot

Go to Google Play or App Store, download and install Telegram.

Install and Download Telegram

Open Telegram and follow the next steps to create a Telegram Bot. First, search for “botfather” and click the BotFather as shown below.

botfather

The following window should open and you’ll be prompted to click the start button.

Telegram Start BotFather to Create a new Bot

Type /newbot and follow the instructions to create your bot. Give it a name and username.

Telegram BotFather Create a New Bot

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 can interact with the bot.

Telegram BotFather Get Bot Token

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

Telegram Get Chat ID with IDBot

Start a conversation 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.

Telegram Get Chat ID with IDBot getid

Preparing Arduino IDE

We’ll program the ESP32 board using Arduino IDE, so make sure you have them installed in your Arduino IDE.

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.

  1. Click here to download the Universal Arduino Telegram Bot library.
  2. Go to Sketch > Include Library > Add.ZIP Library...
  3. Add the library you’ve just downloaded.

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.

  1. Go to Skech > Include Library > Manage Libraries.
  2. Search for “ArduinoJson”.
  3. Install the library.

We’re using ArduinoJson library version 6.5.12.

Install in Arduino IDE the ArduinoJSON library

Parts Required

For this project, you need the following parts:

Schematic Diagram

For this project you need to wire a PIR motion sensor to your ESP32 board. Follow the next schematic diagram.

ESP32 PIR Motion Sensor Wiring Diagram

In this example, we’re wiring the PIR motion sensor data pin to GPIO 27. You can use any other suitable GPIO. Read ESP32 GPIO Guide.

Telegram Motion Detection with Notifications – ESP32 Sketch

The following code uses your Telegram bot to send a warning message to your telegram account whenever motion is detected. To make this sketch work for you, you need to insert your network credentials (SSID and password), the Telegram Bot token and your Telegram user ID.

/*
  Rui Santos
  Complete project details at https://RandomNerdTutorials.com/telegram-esp32-motion-detection-arduino/
  
  Project created using Brian Lough's Universal Telegram Bot Library: https://github.com/witnessmenow/Universal-Arduino-Telegram-Bot
*/

#include <WiFi.h>
#include <WiFiClientSecure.h>
#include <UniversalTelegramBot.h>
#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"

WiFiClientSecure client;
UniversalTelegramBot bot(BOTtoken, client);

const int motionSensor = 27; // PIR Motion Sensor
bool motionDetected = false;

// Indicates when motion is detected
void IRAM_ATTR detectsMovement() {
  //Serial.println("MOTION DETECTED!!!");
  motionDetected = true;
}

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

  // PIR Motion Sensor mode INPUT_PULLUP
  pinMode(motionSensor, INPUT_PULLUP);
  // Set motionSensor pin as interrupt, assign interrupt function and set RISING mode
  attachInterrupt(digitalPinToInterrupt(motionSensor), detectsMovement, RISING);

  // Attempt to connect to Wifi network:
  Serial.print("Connecting Wifi: ");
  Serial.println(ssid);

  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    Serial.print(".");
    delay(500);
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());

  bot.sendMessage(CHAT_ID, "Bot started up", "");
}

void loop() {
  if(motionDetected){
    bot.sendMessage(CHAT_ID, "Motion detected!!", "");
    Serial.println("Motion Detected");
    motionDetected = false;
  }
}

View raw code

How the Code Works

This sections explain how the code works. Continue reading or skip to the Demonstration section.

Start by importing the required libraries.

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

Network Credentials

Insert your network credentials in the following variables.

const char* ssid = "REPLACE_WITH_YOUR_SSID";
const char* password = "REPLACE_WITH_YOUR_PASSWORD";

Telegram Bot Token

Insert your Telegram Bot token you’ve got from Botfather on the BOTtoken variable.

#define BOTtoken "XXXXXXXXXX:XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"  // your Bot Token (Get from Botfather)

Telegram User ID

Insert your chat ID. The one you’ve got from the IDBot.

#define CHAT_ID "XXXXXXXXXX"

Create a new WiFi client with WiFiClientSecure.

WiFiClientSecure client;

Create a bot with the token and client defined earlier.

UniversalTelegramBot bot(BOTtoken, client);

Motion Sensor

Define the GPIO that the motion sensor is connected to.

const int motionSensor = 27; // PIR Motion Sensor

The motionDetected boolean variable is used to indicate whether motion was detected or not. It is set to false by default.

bool motionDetected = false;

detectsMovement()

The detectsmovement() function is a callback function that will be executed when motion is detected. In this case, it simply changes the state of the motionDetected variable to true.

void IRAM_ATTR detectsMovement() {
  //Serial.println("MOTION DETECTED!!!");
  motionDetected = true;
}

setup()

In the setup(), initialize the Serial Monitor.

Serial.begin(115200);

PIR Motion Sensor Interrupt

Set the PIR motion sensor as an interrupt and set the detectsMovement() as the callback function (when motion is detected, that function will be executed):

// PIR Motion Sensor mode INPUT_PULLUP
pinMode(motionSensor, INPUT_PULLUP);
// Set motionSensor pin as interrupt, assign interrupt function and set RISING mode
attachInterrupt(digitalPinToInterrupt(motionSensor), detectsMovement, RISING);

Note: Recommended reading: ESP32 with PIR Motion Sensor using Interrupts and Timers

Init Wi-Fi

Initialize Wi-Fi and connect the ESP32 to your local network with the SSID and password defined earlier.

WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
  delay(1000);
  Serial.println("Connecting to WiFi..");
}

Finally, send a message to indicate that the Bot has started up:

bot.sendMessage(CHAT_ID, "Bot started up", "");

loop()

In the loop(), check the state of the motionDetected variable.

void loop() {
  if(motionDetected){

If it’s true, it means that motion was detected. So, send a message to your Telegram account indicating that motion was detected.

bot.sendMessage(CHAT_ID, "Motion detected!!", "");

Sending a message to the bot is very simply. You just need to use the sendMessage() method on the bot object and pass as arguments the recipient’s chat ID, the message, and the parse mode.

bool sendMessage(String chat_id, String text, String parse_mode = "")

Finally, after sending the message, set the motionDetected variable to false, so it can detect motion again.

motionDetected = false;

That’s pretty much how the code works.

Demonstration

Important: go to your Telegram account and search for your bot. You need to click “start” on a bot before it can message you.

Upload the code to your ESP32 board. Don’t forget to go to Tools > Board and select the board you’re using. Go to Tools > Port and select the COM port your board is connected to.

After uploading the code, press the ESP32 on-board EN/RST button so that it starts running the code. Then, you can open the Serial Monitor to check what’s happening in the background.

When your board first boots, it will send a message to your Telegram account: “Bot started up”. Then, move your hand in front of the PIR motion sensor and check that you’ve received the motion detected notification.

ESP32 ESP8266 Motion Detected Telegram Notification

At the same time, this is what you should get on the Serial Monitor.

ESP32 ESP8266 Telegram Motion Detected Serial Monitor Demonstration

Wrapping Up

In this tutorial you’ve learned how to create a Telegram Bot to interact with the ESP32 board. When motion is detected, a message is sent.

With this bot, you can also use your Telegram account to send messages to the ESP32 to control its outputs or request sensor readings, for example.

The great thing about using Telegram to control your ESP boards, is that as long as you have an internet connection (and your boards too), you can control and monitor them from anywhere in the world.

More projects with Telegram:

We hope you’ve found this project interesting. Learn more about the ESP32 with our resources:

Thanks for reading.


Learn how to program and build projects with the ESP32 and ESP8266 using MicroPython firmware DOWNLOAD »

Learn how to program and build projects with the ESP32 and ESP8266 using MicroPython firmware DOWNLOAD »


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16 thoughts on “Telegram: ESP32 Motion Detection with Notifications (Arduino IDE)”

  1. Hi, is this project locally or motion detected can be discovered even if my smartphone and esp32 aren’t connected to the same network (WiFi)

    Reply
    • Hi.
      The smartphone and ESP32 don’t need to be on the same network.
      You’ll be notified no matter where you are.
      Regards,
      Sara

      Reply
  2. Very good projects.
    I hope you will look into ESP32-CAM, and send a picture when motion is detected to Telegram.

    Reply
  3. Hi Sara, great tutorial, as ever! If the telegram account is set up on a smart phone is there an easy way to get the very long BotToken onto the PC for adding into the ESP32 code? Or, can the Telegram account be set up from a PC?

    Reply
  4. Hi
    I have the code uploaded to an ESP32 board, and it all seems to work. The board connects to my wifi and receives a valid IP address. I currently have a switch connected in place of the motion detector output on D27 and when the switch is operated, the “motion detected” message comes up in the serial monitor window. However, I don’t get any notification come up on the phone. I created the Bot and got an ID as instructed in the tutorial. Also the Bot token string. I put these into the sketch in the appropriate places. I can find my account ok in Telegram and I was able to start the Bot ok (I think). I have the desktop app installed as well, and I can send a message from the desktop to the phone. So what is going wrong with the ESP board sending a message to the phone. Any thoughts ?

    Reply
    • OK. Ignore that ! Got it. You have to be very VERY careful of the token string. I had mistaken an upper case “O” for a zero … Now that I have put that right, it is sending messages without a problem 🙂

      Reply
  5. Hello,

    I followed your tutorial. I use the ESP32-WROOM-32D hardware.
    I experienced a small issue – compiler errors with the JSON library.
    I installed version 5 instead of version 6 and code runs like a charm.
    Congrats with your work. I am a fan of RNT.
    Keep up the good work!

    Reply

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