/*
  Code for controlling Appliances and Monitoring sensor's data over MQTT
  This code is written for NodeMCU board with 4 Relays & DHT11 Sensor

  I demonstrated this code by using Mosquitto MQTT broker on my Raspberry Pi board. Watch out the full
  tutorial video on my channel to understand this code and the project as well

  YouTube Channel :- https://www.youtube.com/techiesms


          techiesms
  explore | learn | share
*/

#include <WiFi.h>
#include <PubSubClient.h>
#include <DHT.h>

//Relays for switching appliances
#define Relay1            D6
#define Relay2            D2
#define Relay3            D1
#define Relay4            D5

//DHT11 for reading temperature and humidity value
#define DHTPIN            D7

// Uncomment whatever type you're using!
#define DHTTYPE DHT11     // DHT 11
//#define DHTTYPE DHT22   // DHT 22, AM2302, AM2321
//#define DHTTYPE DHT21   // DHT 21, AM2301

DHT dht(DHTPIN, DHTTYPE);

// Update these with values suitable for your network.

const char* ssid = "SSID";
const char* password = "PASS";
const char* mqtt_server = "XXX.XXX.XXX.XXX";  // Local IP address of Raspberry Pi

const char* username = "MQTT_USERNAME";
const char* pass = "MQTT_PASSWORD";

#define sub1 "device2/relay1"
#define sub2 "device2/relay2"
#define sub3 "device2/relay3"
#define sub4 "device2/relay4"


char str_hum_data[10];
char str_temp_data[10];



WiFiClient espClient;
PubSubClient client(espClient);
unsigned long lastMsg = 0;
#define MSG_BUFFER_SIZE  (50)
char msg[MSG_BUFFER_SIZE];
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.mode(WIFI_STA);
  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("] ");

  if (strstr(topic, sub1))
  {
    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(Relay1, HIGH);   // Turn the LED on (Note that LOW is the voltage level
      // but actually the LED is on; this is because
      // it is active low on the ESP-01)
    } else {
      digitalWrite(Relay1, LOW);  // Turn the LED off by making the voltage HIGH
    }
  }

  else if ( strstr(topic, sub2))
  {
    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(Relay2, HIGH);   // Turn the LED on (Note that LOW is the voltage level
      // but actually the LED is on; this is because
      // it is active low on the ESP-01)
    } else {
      digitalWrite(Relay2, LOW);  // Turn the LED off by making the voltage HIGH
    }
  }
  else if ( strstr(topic, sub3))
  {
    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(Relay3, HIGH);   // Turn the LED on (Note that LOW is the voltage level
      // but actually the LED is on; this is because
      // it is active low on the ESP-01)
    } else {
      digitalWrite(Relay3, LOW);  // Turn the LED off by making the voltage HIGH
    }
  }
  else if ( strstr(topic, sub4))
  {
    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(Relay4, HIGH);   // Turn the LED on (Note that LOW is the voltage level
      // but actually the LED is on; this is because
      // it is active low on the ESP-01)
    } else {
      digitalWrite(Relay4, LOW);  // Turn the LED off by making the voltage HIGH
    }
  }

  else
  {
    Serial.println("unsubscribed topic");
  }



}

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, pass) ) {
      Serial.println("connected");
      // Once connected, publish an announcement...
      // ... and resubscribe
      client.subscribe(sub1);
      client.subscribe(sub2);
      client.subscribe(sub3);
      client.subscribe(sub4);
    } 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(Relay1, OUTPUT);
  pinMode(Relay2, OUTPUT);
  pinMode(Relay3, OUTPUT);
  pinMode(Relay4, OUTPUT);
  Serial.begin(115200);
  dht.begin();
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}

void loop() {

  if (!client.connected()) {
    reconnect();
  }
  client.loop();

  unsigned long now = millis();
  if (now - lastMsg > 2000) {
    float hum_data = dht.readHumidity();
    Serial.println(hum_data);
    /* 4 is mininum width, 2 is precision; float value is copied onto str_sensor*/
    dtostrf(hum_data, 4, 2, str_hum_data);
    float temp_data = dht.readTemperature(); // or dht.readTemperature(true) for Fahrenheit
    dtostrf(temp_data, 4, 2, str_temp_data);
    lastMsg = now;
    Serial.print("Publish message: ");
    Serial.print("Temperature - "); Serial.println(str_temp_data);
    client.publish("device2/temp", str_temp_data);
    Serial.print("Humidity - "); Serial.println(str_hum_data);
    client.publish("device2/hum", str_hum_data);
  }
}