esp32MQTTAdafruit.ino

/***************************************************
Complete IoT Project with DHT22, Relay and ESP32 Huzzah Board

DHT Sensor connected to PIn 27
Relay Connected to Pin 12
 ****************************************************/

#include <WiFi.h>
#include "Adafruit_MQTT.h"
#include "Adafruit_MQTT_Client.h"

/************************* WiFi Access Point *********************************/

#define WLAN_SSID       "Robotics Lab"  // replace it with your Wifi Name
#define WLAN_PASS       "Robotics@321"  // Replace it with your wifi password

/************************* Adafruit.io Setup *********************************/

#define AIO_SERVER      "io.adafruit.com"
#define AIO_SERVERPORT  1883                   // use 8883 for SSL
#define AIO_USERNAME    "amitrana3348"  // Change this to your username
#define AIO_KEY         "3e359482c74e59509c3f50ab76e3a80958f55033"  // Change this to your key

#include "DHT.h"
#define DHTPIN 27 // dht connection
#define DHTTYPE DHT22   // DHT 22  connected to pin 27
DHT dht(DHTPIN, DHTTYPE);

int rel = 12;


/************ Global State (you don't need to change this!) ******************/

WiFiClient client;
// Setup the MQTT client class by passing in the WiFi client and MQTT server and login details.
Adafruit_MQTT_Client mqtt(&client, AIO_SERVER, AIO_SERVERPORT, AIO_USERNAME, AIO_KEY);

/****************************** Feeds ***************************************/

Adafruit_MQTT_Publish temperature = Adafruit_MQTT_Publish(&mqtt, AIO_USERNAME "/feeds/temperature");
Adafruit_MQTT_Publish humidity = Adafruit_MQTT_Publish(&mqtt, AIO_USERNAME "/feeds/humidity");
Adafruit_MQTT_Subscribe relay = Adafruit_MQTT_Subscribe(&mqtt, AIO_USERNAME "/feeds/relay");
Adafruit_MQTT_Subscribe led = Adafruit_MQTT_Subscribe(&mqtt, AIO_USERNAME "/feeds/led");

/*************************** Sketch Code ************************************/

// Bug workaround for Arduino 1.6.6, it seems to need a function declaration
// for some reason (only affects ESP8266, likely an arduino-builder bug).
void MQTT_connect();

void setup() 
{
  Serial.begin(9600);
  delay(10);
  pinMode(rel,OUTPUT); digitalWrite(rel,LOW);
  pinMode(LED_BUILTIN,OUTPUT); digitalWrite(LED_BUILTIN,LOW);
  Serial.println(F("Adafruit MQTT demo"));

  // Connect to WiFi access point.
  Serial.println(); Serial.println();
  Serial.print("Connecting to ");
  Serial.println(WLAN_SSID);

  WiFi.begin(WLAN_SSID, WLAN_PASS);
  while (WiFi.status() != WL_CONNECTED) 
  {
    delay(500);
    Serial.print(".");
  }
  Serial.println();

  Serial.println("WiFi connected");
  Serial.println("IP address: "); Serial.println(WiFi.localIP());

  // Setup MQTT subscription for onoff feed.
  mqtt.subscribe(&relay);
  mqtt.subscribe(&led);
  dht.begin();
}


void loop() 
{
  // Ensure the connection to the MQTT server is alive (this will make the first
  // connection and automatically reconnect when disconnected).  See the MQTT_connect
  // function definition further below.
  MQTT_connect();

  // this is our 'wait for incoming subscription packets' busy subloop
  // try to spend your time here

  Adafruit_MQTT_Subscribe *subscription;
  while ((subscription = mqtt.readSubscription(5000))) 
  {
    if (subscription == &led) 
    {
      Serial.print(F("Got: "));
      Serial.println((char *)led.lastread);
      if(strcmp((char *)led.lastread, "ON") == 0) 
      {
        digitalWrite(LED_BUILTIN,HIGH);
        Serial.println("LED Turned ON");
      }
      if(strcmp((char *)led.lastread, "OFF") == 0)
      {
        digitalWrite(LED_BUILTIN,LOW);
        Serial.println("LED Turned OFF");
      }
    }
    
    if (subscription == &relay) 
    {
      Serial.print(F("Got: "));
      Serial.println((char *)relay.lastread);
      if(strcmp((char *)relay.lastread, "ON") == 0) 
      {
        digitalWrite(rel,HIGH);
        Serial.println("Relay Turned ON");
      }
      if(strcmp((char *)relay.lastread, "OFF") == 0)
      {
        digitalWrite(rel,LOW);
        Serial.println("Relay Turned OFF");
      }
    }
  }

  // Now we can publish stuff!
  float h = dht.readHumidity(); 
  float t = dht.readTemperature();
 
  Serial.print(F("\nSending Temperature value "));
  Serial.print(t);
  Serial.print("...");
  if (! temperature.publish(t)) 
  {
    Serial.println(F("Failed"));
  } 
  else 
  {
    Serial.println(F("OK!"));
  }
  delay(1500);
  Serial.print(F("\nSending Humidity value "));
  Serial.print(h);
  Serial.print("...");
  if (! humidity.publish(h)) 
  {
    Serial.println(F("Failed"));
  } 
  else 
  {
    Serial.println(F("OK!"));
  }
  Serial.println("*******************************************************************************************");
  
  delay(1500);

  // ping the server to keep the mqtt connection alive
  // NOT required if you are publishing once every KEEPALIVE seconds
  /*
  if(! mqtt.ping()) {
    mqtt.disconnect();
  }
  */
}

// Function to connect and reconnect as necessary to the MQTT server.
// Should be called in the loop function and it will take care if connecting.
void MQTT_connect() 
{
  unsigned char 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!");
}