Telegram Bot (MRLbot experimentations)

Experimentation's with a TelegramBot polling an ESP32.

These Bots can be found or created via the Telegram App Messaging service...

(in our case I have called it "MRLbot" )

MRLbot & ESP32 Marriage possibilities :-

Send Text Messages remotely (both ways)
Send Pictures .... (both ways, using Spiffs or SD card)
Send Controls and Status messages (both ways)
Control GPIO pins both Input&output

Creation of a Bot is achieved Via an entity/user called "Botfather" who you can find by searching persons in the search bar of the Telegram App (its simple to set up and process/guidance is well documented).

Once the TelegramBot is created the ESP32 needs the Telegram Library (I recommend Brian Lough's)

During the Bot registration process you will be sent a BOTtoken which is unique to your Bot and should be kept safe .... unless you would want multiple persons to use it !!!

Here is some code for controlling 3 Led's and sending Hall_Effect Sensor values back

// An example of bot that receives commands and turns on and off RGB LED
// Also sends back Hall_Effect Sensor Values of ESP32
#include <WiFi.h>
#include <WiFiClientSecure.h>
#include <UniversalTelegramBot.h>

// Initialize Wifi connection to the router
char ssid[] = "YOUR WIFI NETWORK"; // your network SSID (name)
char password[] = "YOUR NETWORK PASSWORD"; // your network key

// Initialize Telegram BOT
#define BOTtoken "THIS IS OBTAINED WHEN YOU REGISTER YOUR BOT - DO NOT SHARE PUBLICLY" // your Bot Token (Get from Botfather)

WiFiClientSecure client;
UniversalTelegramBot bot(BOTtoken, client);

int Bot_mtbs = 1000; //mean time between scan messages
long Bot_lasttime; //last time messages' scan has been done
bool Start = false;

const int RedledPin = 18;
const int GreenledPin = 19;
const int BlueledPin = 21;
int val=0;

int RedledStatus = 0;
int GreenledStatus = 0;
int BlueledStatus = 0;

void handleNewMessages(int numNewMessages) {
Serial.println("handleNewMessages");
Serial.println(String(numNewMessages));

for (int i=0; i<numNewMessages; i++) {
String chat_id = String(bot.messages[i].chat_id);
String text = bot.messages[i].text;

String from_name = bot.messages[i].from_name;
if (from_name == "") from_name = "Guest";

    if (text == "/Redledon") {digitalWrite(RedledPin, HIGH); RedledStatus = 1;   bot.sendMessage(chat_id, "Red Led is ON", ""); }
    if (text == "/Redledoff"){ RedledStatus = 0; digitalWrite(RedledPin, LOW);       bot.sendMessage(chat_id, "Red Led is OFF", ""); }
    if (text == "/Redstatus"){ if(RedledStatus){ bot.sendMessage(chat_id, "Red Led is ON", ""); } else { bot.sendMessage(chat_id, "Red Led is OFF", ""); } }
    if (text == "/Greenledon") {digitalWrite(GreenledPin, HIGH); GreenledStatus = 1;   bot.sendMessage(chat_id, "Green Led is ON", ""); }
    if (text == "/Greenledoff"){ GreenledStatus = 0; digitalWrite(GreenledPin, LOW);       bot.sendMessage(chat_id, "Green Led is OFF", ""); }
    if (text == "/Greenstatus"){ if(GreenledStatus){ bot.sendMessage(chat_id, "Green Led is ON", ""); } else { bot.sendMessage(chat_id, "Green Led is OFF", ""); } }
    if (text == "/Blueledon") {digitalWrite(BlueledPin, HIGH); BlueledStatus = 1;   bot.sendMessage(chat_id, "Blue Led is ON", ""); }
    if (text == "/Blueledoff"){ BlueledStatus = 0; digitalWrite(BlueledPin, LOW);       bot.sendMessage(chat_id, "Blue Led is OFF", ""); }
    if (text == "/Bluestatus"){ if(BlueledStatus){ bot.sendMessage(chat_id, "Green Led is ON", ""); } else { bot.sendMessage(chat_id, "Blue Led is OFF", ""); } }

    if (text == "/start") {
      String welcome = "Welcome to Universal Arduino Telegram Bot library.\n";
      welcome += "This is Flash Led Bot example.\n\n";
      welcome += "/Redledon    :switch Red Led ON\n";
      welcome += "/Redledoff   :switch Red Led OFF\n";
      welcome += "/Redstatus   :status Red LED\n";
      welcome += "/Greenledon :switch Green Led ON\n";
      welcome += "/Greenledoff :switch Green Led OFF\n";
      welcome += "/Greenstatus :status Green LED\n";
      welcome += "/Blueledon   :switch Blue Led ON\n";
      welcome += "/Blueledoff :switch Blue Led OFF\n";
      welcome += "/Bluestatus :status Blue LED\n";

      bot.sendMessage(chat_id, welcome, "Markdown");
    }
}
}

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

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

// Set WiFi to station mode and disconnect from an AP if it was Previously
// connected
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());

pinMode(RedledPin, OUTPUT); delay(10); digitalWrite(RedledPin, LOW);
pinMode(GreenledPin, OUTPUT); delay(10); digitalWrite(GreenledPin, LOW);
pinMode(BlueledPin, OUTPUT); delay(10); digitalWrite(BlueledPin, LOW);
}

void loop() {
if (millis() > Bot_lasttime + Bot_mtbs) {
    int numNewMessages = bot.getUpdates(bot.last_message_received + 1);
    int val = hallRead(); Serial.println(val);
    String chat_id = String(bot.messages[0].chat_id);
if (val>10){bot.sendMessage(chat_id, String(val), ""); RedledStatus = 0;GreenledStatus = 0;BlueledStatus = 0;digitalWrite(RedledPin, LOW); digitalWrite(GreenledPin, LOW); digitalWrite(BlueledPin, LOW);}
    while(numNewMessages) {
      Serial.println("got response");
      handleNewMessages(numNewMessages);

numNewMessages = bot.getUpdates(bot.last_message_received + 1);
}

Bot_lasttime = millis();
}
}

Once uploaded the ESP32 will poll the Telegram server at intervals (in our case every second (Circa))

Then on your Phone/PC or Tablet via the Telegram App you can bring up the MRLbot and interact with it.

I have extended the Command list to be able to control a RGB led.

Typing "/start" brings up the list of commands

A while back I was using the ESP32's inbuilt Magnetic Hall Effect Sensor... this can be read and also the analoge values sent back to your Telegram Chat.

(Could easily be used as a simple intruder alert (Magnet on door) ;-)

Another neat parameter is the ability to include some json formating for custom keyboard buttons :-

In this example you can store a list of URL pictures on your ESP and recall them via the Telegram App

String test_photo_url = "http://myrobotlab.org/sites/default/files/logo.png";

if (text == "/get_test_photo") { bot.sendPhoto(chat_id, test_photo_url, ""); }

I am awaiting some more ESP32_Cams to be able to send Polled camera picture back to my Chat.,, Stay Tuned.

(N.B. Telegram gives you a LOT of control over what happens to your messages, tons more control than others that will remain nameless).