Sonoff Basic with button

/*****

 All the resources for this project:
 https://rntlab.com/
 This is the code to flash sonoff basic. Search for sonoffxxX
 and replace xx with next higher number.
 As of 6/11/2019 there are 01X , 02X ,03X, 04X, 05X, 06X, 10X, A1, A2,  in operation.
 The X designates the device that sends the state message.
 The XA designates the device that sends a state message and has manual control
*****/

// Loading the ESP8266WiFi library and the PubSubClient library
#include <ESP8266WiFi.h>
#include <PubSubClient.h>

// Change the credentials below, so your ESP8266 connects to your router
const char* ssid = "xxxxx";
const char* password = "xxxxxxx";

// Change the variable to your Raspberry Pi IP address, so it connects to your MQTT broker
const char* mqtt_server = "192.168.1.xxx";

// Initializes the espClient
WiFiClient espClient;
PubSubClient client(espClient);

// GPIOs of your ESP8266 on your sonoffxxX
int gpio13Led = 13;
int gpio12Relay = 12;
int buttonPin = 0;

// Variables will change:
int ledState = HIGH;         // the current state of the output pin
int buttonState;             // the current reading from the input pin
int lastButtonState = LOW;   // the previous reading from the input pin

// the following variables are unsigned longs because the time, measured in
// milliseconds, will quickly become a bigger number than can be stored in an int.
unsigned long lastDebounceTime = 0;  // the last time the output pin was toggled
unsigned long debounceDelay = 50;    // the debounce time; increase if the output flickers


// Don't change the function below. This functions connects your ESP8266 to your router
void setup_wifi() {
  delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.print("WiFi connected - ESP IP address: ");
  Serial.println(WiFi.localIP());
}

// This functions is executed when some device publishes a message
// to a topic that your ESP8266 is subscribed to
// Change the function below to add logic to your program,
// so when a device publishes a message to a topic that
// your ESP8266 is subscribed you can actually do something
void callback(String topic, byte* message, unsigned int length) {
  Serial.print("Message arrived on topic: ");
  Serial.print(topic);
  Serial.print(". Message: ");
  String messageTemp;

  for (int i = 0; i < length; i++) {
    Serial.print((char)message[i]);
    messageTemp += (char)message[i];
  }
  Serial.println();

  // Feel free to add more if statements to control more GPIOs with MQTT

  // If a message is received on the topic home/office/sonoffxxX,
  // you check if the message is either 1 or 0.
  // Turns the ESP GPIO according to the message

  if(topic=="home/office/sonoff02X"){
      Serial.print("Changing sonoff02X to ");
      if(messageTemp == "on");
      else if (ledState == HIGH); {
        digitalWrite(gpio13Led, LOW); //turns LED ON
        digitalWrite(gpio12Relay, HIGH); //energizes relay
        Serial.print("On");
        client.publish("home/office/sonoff02X/state","on"); //sends "ON" message to NR
      }
  }
      else if(messageTemp == "off"){
        digitalWrite(gpio13Led, HIGH);  //turns LED OFF
        digitalWrite(gpio12Relay, LOW);  //deenergizes relay
        Serial.print("Off");
       client.publish("home/office/sonoff02X/state","off");//sends "OFF" message to NR
      }

  Serial.println();
}

// This functions reconnects your ESP8266 to your MQTT broker
// Change the function below if you want to subscribe to more topics with your ESP8266
void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Attempt to connect
    /*
     YOU MIGHT NEED TO CHANGE THIS LINE, IF YOU'RE HAVING
     PROBLEMS WITH MQTT MULTIPLE CONNECTIONS
     To change the ESP device ID, you will have
     to give a new name to the ESP8266.
     Here's how it looks:
       if (client.connect("ESP8266Client")) {
     You can do it like this:
       if (client.connect("ESP1_Office")) {
     Then, for the other ESP:
       if (client.connect("ESP2_Garage")) {
      That should solve your MQTT multiple connections problem
    */
    if (client.connect("sonoff02X")) {
      Serial.println("connected");
      // Subscribe or resubscribe to a topic
      // You can subscribe to more topics (to control more sonoffxxXs)
      client.subscribe("home/office/sonoff02X");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}

// The setup function sets your ESP GPIOs to Outputs,
// starts the serial communication at a baud rate of 115200
// Sets your mqtt broker and sets the callback function
// The callback function is what receives messages
// and actually controls the LEDs
void setup() {
  // preparing GPIOs

   pinMode(buttonPin, INPUT);
   pinMode(gpio13Led, OUTPUT);
   digitalWrite(gpio13Led, HIGH);

   pinMode(gpio12Relay, OUTPUT);
   digitalWrite(gpio12Relay, HIGH);

  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}



// For this project, you don't need to change anything in the loop function.
// Basically it ensures that you ESP is connected to your broker
void loop() {
  // read the state of the switch into a local variable:
  int reading = digitalRead(buttonPin);

  // check to see if you just pressed the button
  // (i.e. the input went from LOW to HIGH), and you've waited long enough
  // since the last press to ignore any noise:

  // If the switch changed, due to noise or pressing:
  if (reading != lastButtonState) {
    // reset the debouncing timer
    lastDebounceTime = millis();
  }

  if ((millis() - lastDebounceTime) > debounceDelay) {
    // whatever the reading is at, it's been there for longer than the debounce
    // delay, so take it as the actual current state:

    // if the button state has changed:
    if (reading != buttonState) {
      buttonState = reading;

      // only toggle the LED if the new button state is HIGH
      if (buttonState == HIGH) {
        ledState = !ledState;
      }
    }
  }

  // set the LED:
  digitalWrite(gpio13Led, ledState);

  // save the reading. Next time through the loop, it'll be the lastButtonState:
  lastButtonState = reading;




  if (!client.connected()) {
    reconnect();
  }
  if(!client.loop())
    client.connect("sonoff02X");
  }