ESP8266 based IOT Temperature Monitor using Adafruit Broker : IOT Part 21

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//Program to 

/*

File Name- PC_to_ESP8266_communication_with_adafruit_broker.ino

Output pin of ESP-01

GPIO2-DHT11 sensor

*/

//Include libraries

#include                         //Include library for ESP8266 configuration   

#include "Adafruit_MQTT.h"                      //Include library for MQTT 

#include "Adafruit_MQTT_Client.h"

#include "DHT.h"                                //Include library for Temperature and humidity sensor configuration

// DHT11 or DHT22 pin and Type declaration

#define DHTPIN 2                                //DHT11 ouptput connected to ESP-01 GPIO02

#define DHTTYPE DHT11                           //DHT TYPE-DHT 11 or 22

DHT dht(DHTPIN, DHTTYPE, 15);                   //Create the instance for DHT sensor

// WiFi parameters

#define WLAN_SSID       "Replace it with the SSID of the Wi-Fi Network"                 //SSID of Home's WiFi network

#define WLAN_PASS       "Replace it with the password of the Wi-Fi Network"             //Password of Home's WiFi network

// Adafruit IO Broker Initialization

#define AIO_SERVER      "io.adafruit.com"      //Broker domain Name

#define AIO_SERVERPORT  1883                   //The port at which broker is listening

#define AIO_USERNAME    "priya22"              //The username which we have initializaed during account creation at io.adafruit.com

#define AIO_KEY         "acd65714ad7f4217a6b1c1c4815fcfa4"  //The private ley which will be alloted after creating account

//Create an ESP8266 WiFiClient class to connect to the MQTT server.

WiFiClient espclient;

// Setup the MQTT client class by passing in the WiFi client and MQTT server and login details.

Adafruit_MQTT_Client mqtt(&espclient, AIO_SERVER, AIO_SERVERPORT, AIO_USERNAME, AIO_KEY);

//Create the topic to be registered on MQTT broker

//Notice MQTT paths for AIO follow the form: /feeds/

Adafruit_MQTT_Publish temp = Adafruit_MQTT_Publish(&mqtt, AIO_USERNAME "/feeds/temp");

Adafruit_MQTT_Publish humidity = Adafruit_MQTT_Publish(&mqtt, AIO_USERNAME "/feeds/humidity");

//Function declaration

void MQTT_connect();

void setup() {

  Serial.begin(115200);                   //Start the serial communication for debugging 

  delay(10);

  dht.begin();                           //DHT sensor initialization

  //Connect to WiFi access point.

  Serial.println(); Serial.println();

  Serial.print("Connecting to ");

  Serial.println(WLAN_SSID);

  WiFi.begin(WLAN_SSID, WLAN_PASS);

  // Wait until the connection has been confirmed before continuing

  while (WiFi.status() != WL_CONNECTED) {

    delay(500);

      Serial.print(".");

    }

  Serial.println();

  Serial.println("WiFi connected");

    Serial.println("IP address: "); 

  Serial.println(WiFi.localIP());

}

void loop() {

  MQTT_connect();

  float temperature_data = 32.0; //dht.readTemperature();     //Read the current temperature

  float humidity_data = 51.0; //dht.readHumidity();           //Read the current humidity

 

  // Now we can publish stuff!

  Serial.print(F("nSending temperature value "));

  Serial.print(temperature_data);

  Serial.print("...");

  //Publish the temperature to the Adafruit broker

  if (! temp.publish(temperature_data)) 

  {

    Serial.println(F("Failed"));

    } else 

    {

      Serial.println(F("OK!"));

      }

    Serial.print(F("nSending Humidity value "));

    Serial.print(humidity_data);

    Serial.print("...");

    //Publish the humidity to the Adafruit broker

    if (! humidity.publish(humidity_data)) 

    {

      Serial.println(F("Failed"));

      } else 

    {

      Serial.println(F("OK!"));

      }

      delay(10000);

}

/*

Function Name- MQTT_connect()

Function to connect and reconnect as necessary to the MQTT server.

It should be called in the loop function and it will take care if connecting.

*/

 void MQTT_connect() {

  int8_t ret;

  //Stop if already connected.

  if (mqtt.connected()) {

    return;

  }

  Serial.print("Connecting to MQTT... ");

  uint8_t retries = 3;

    while ((ret = mqtt.connect()) != 0) {     // connect will return 0 for connected

       Serial.println(mqtt.connectErrorString(ret));

       Serial.println("Retrying MQTT connection in 5 seconds...");

       mqtt.disconnect();

       delay(5000);               // wait 5 seconds

       retries--;

       if (retries == 0) {

         // basically die and wait for WDT to reset me

         while (1);

       }

  }

  Serial.println("MQTT Connected!");

}

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