Uploading and Receiving Data from Cloud using ESP8266

Step1:

Create an Account in www.cloudmqtt.com





Step2
Create an instance which will be used in the program to publish data to the cloud.









Step3:
Select the Instance name (test_1) and use the details of the same in the code.






Include the details in the code:


Step4:
Inorder to send a message to the CloudMQTT, include the line
 client.publish("topic_name", "Message");





The message sent will appear in the WEBSOCKET UI of the specified Instance.




Step5:
To send data from CloudMQTT ,include the line 
client.subscribe("Topic_name");



The same Topic_name should be used in the WEBSOCKET UI as specified in the code while sending the message

Step6:
The following code prints the received data from the cloud in the Serial Monitor:






Step7:
The final code establishing connecting between ESP8266 and Cloud MQTT is given below:

# include <ESP8266WiFi.h>

#include <PubSubClient.h>

 const char* ssid = "Your WiFi Username";

const char* password = "Wifi Password";

const char* mqttServer = "m10.cloudmqtt.com"; // Details from the instance created

const int mqttPort = 18015;

const char* mqttUser = "dswvkhpd";

const char* mqttPassword = "rqVQavi1Y-p9";

WiFiClient espClient;

PubSubClient client(espClient);

void setup()

{

Serial.begin(115200);

WiFi.begin(ssid, password);

while (WiFi.status() != WL_CONNECTED) // Connecting ESP8266 to WiFi

 {

    delay(500);

    Serial.println("Connecting to WiFi..");

   

 }

 Serial.println("Connected to the WiFi network");

 client.setServer(mqttServer, mqttPort);

 client.setCallback(callback);

 while (!client.connected()) // Connecting to CloudMqtt

 {

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

    if (client.connect("ESP8266Client", mqttUser, mqttPassword ))

   {

   Serial.println("connected"); 

    }

    else

    {

      Serial.print("failed with state ");

      Serial.print(client.state());

      delay(2000);

    }

 }

  client.publish("test1", "Hello from RDL_IOT"); // Sending message to Topic "test1"

  client.subscribe("test"); //Receives message sent to the topic "test"

}

void callback(char* topic, byte* payload, unsigned int length) // This function is used to         //print the incoming data sent to the topic "test"

{

  uint8_t s;

  Serial.print("Message arrived in topic: ");

  Serial.println(topic);

  Serial.print("Message:");

  for (int i = 0; i < length; i++)

  {

    s= payload[i];

    Serial.write(s); 

  }

}

void loop()

{

  client.loop();

}

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