text: #include <ESP8266WiFi.h>
  #include <PubSubClient.h>
  
  
  const char *ssid = "JioFi2_AB7347"; 
  const char *password = "tchcrpcf3x"; 
  const char *mqtt_server = "raushanraja.dev"; 
  const char *device_id = "esp8266";
  
  
  
  // Update these with values suitable for your network.
  
  WiFiClient espClient;
  PubSubClient client(espClient);
  unsigned long lastMsg = 0;
  #define MSG_BUFFER_SIZE	(50)
  char msg[MSG_BUFFER_SIZE];
  String reply="";
  int value = 0;
  
  void setup_wifi() {
  
    delay(10);
    // We start by connecting to a WiFi network
    Serial.println();
    Serial.print("Connecting to ");
    Serial.println(ssid);
  
    WiFi.begin(ssid, password);
  
    while (WiFi.status() != WL_CONNECTED) {
      delay(500);
      Serial.print(".");
    }
  
    randomSeed(micros());
  
    Serial.println("");
    Serial.println("WiFi connected");
    Serial.println("IP address: ");
    Serial.println(WiFi.localIP());
  }
  
  void callback(char* topic, byte* payload, unsigned int length) {
    Serial.print("Message arrived [");
    Serial.print(topic);
    Serial.print("] ");
    for (int i = 0; i < length; i++) {
      Serial.print((char)payload[i]);
    }
    Serial.println();
  
    // Switch on the LED if an 1 was received as first character
    if ((char)payload[0] == '1') {
      digitalWrite(LED_BUILTIN, LOW);   // Turn the LED on (Note that LOW is the voltage level
      client.publish("test/reply", "LED ON");
  
      // but actually the LED is on; this is because
      // it is active low on the ESP-01)
    } else  if ((char)payload[0] == '0') {
      digitalWrite(LED_BUILTIN, HIGH);  // Turn the LED off by making the voltage HIGH
      client.publish("test/reply", "LED OFF");
  
    }
  
  }
  
  void reconnect() {
    // Loop until we're reconnected
    while (!client.connected()) {
      Serial.print("Attempting MQTT connection...");
      // Create a random client ID
      String clientId = "ESP8266Client-";
      clientId += String(random(0xffff), HEX);
      // Attempt to connect
      if (client.connect(clientId.c_str(),"username","password")) {   // Change username and password
        Serial.println("connected");
        // Once connected, publish an announcement...
        //   client.publish("test/iot", "hello world");
        client.publish("test/reply", "LED OFF");
        // ... and resubscribe
        client.subscribe("test/iot");
      } else {
        Serial.print("failed, rc=");
        Serial.print(client.state());
        Serial.println(" try again in 5 seconds");
        // Wait 5 seconds before retrying
        delay(5000);
      }
    }
  }
  
  void setup() {
    pinMode(LED_BUILTIN, OUTPUT);     // Initialize the LED_BUILTIN pin as an output
    Serial.begin(9600);
    setup_wifi();
    client.setServer(mqtt_server, 1883);
    client.setCallback(callback);
    digitalWrite(LED_BUILTIN,1);
  }
  
  void loop() {
  
    if (!client.connected()) {
      reconnect();
    }
    client.loop();
  
    unsigned long now = millis();
    if (now - lastMsg > 2000) {
      lastMsg = now;
      ++value;
      // snprintf (msg, MSG_BUFFER_SIZE, "hello world #%ld", value);
      // Serial.print("Publish message: ");
      // Serial.println(msg);
      // client.publish("test/reply", "msg");
    }
  }
  