ArduinoSketch.ino

/*
 MQTT Arduino Publisher Sketch
*/

#include <SPI.h>
#include <Ethernet.h>
#include <PubSubClient.h>
#include <dht.h>
#define DHT11_PIN 8 
#define TOPIC "LK/Shazin/Home/Hall/ThermoStat"

// Update these with values suitable for your network.
byte mac[]    = {  0xDE, 0xED, 0xBA, 0xFE, 0xFE, 0xED };
byte server[] = { 192, 168, 1, 4 };
byte ip[]     = { 192, 168, 1, 10 };
byte gserver[] = { 64, 233, 187, 99 }; // Google

dht DHT;

void callback(char* topic, byte* payload, unsigned int length) {
  // handle message arrived
}

EthernetClient ethClient;
PubSubClient client(server, 1883, callback, ethClient);

void setup()
{
  Serial.begin(9600);
  Ethernet.begin(mac, ip);
  Serial.println("Ethernet Registered");
  if (client.connect("arduinoClient")) {
    client.publish(TOPIC,0);
    Serial.println("Topic Registered");
  }
}

void loop()
{
  int chk = DHT.read11(DHT11_PIN);
  switch (chk)
  {
    case DHTLIB_OK:  
        Serial.print("OK,\t"); 
        break;
    case DHTLIB_ERROR_CHECKSUM: 
        Serial.print("Checksum error,\t"); 
        break;
    case DHTLIB_ERROR_TIMEOUT: 
        Serial.print("Time out error,\t"); 
        break;
    case DHTLIB_ERROR_CONNECT:
        Serial.print("Connect error,\t");
        break;
    case DHTLIB_ERROR_ACK_L:
        Serial.print("Ack Low error,\t");
        break;
    case DHTLIB_ERROR_ACK_H:
        Serial.print("Ack High error,\t");
        break;
    default: 
        Serial.print("Unknown error,\t"); 
        break;
  }

  Serial.print(DHT.humidity, 1);
  Serial.print(",\t");
  Serial.println(DHT.temperature, 1);

  int temp = (int) DHT.temperature;
  int humi = (int) DHT.humidity;
  String str = "{\"temperature\":"+String(temp)+",\"humidity\":"+String(humi)+"}";
  char c[str.length()+1];
  // Convert to a String
  str.toCharArray(c, str.length()+1);
  // Publish to topic
  client.publish(TOPIC, c);
  Serial.print("sent ");
  Serial.println(c);
  client.loop();
  delay(100);
}