Activated Devices with Voice

#include <SoftwareSerial.h>
SoftwareSerial esp8266(3, 2); //RX pin = 3, TX pin = 2
int state = 5; //define initial (5 = stand-by)
#define DEBUG true //show messages between ESP8266 and Arduino in serial port

void setup() {
  esp8266.begin(9600);
  Serial.begin(9600);
  pinMode (10, OUTPUT); // LED attached here

  sendData("AT+RST\r\n", 2000, DEBUG); //reset module
  delay(1000);
  sendData("AT+CWMODE=1\r\n", 1000, DEBUG); //set station mode
  delay(1000);
  sendData("AT+CWJAP=\"WIFI_SSID\",\"WIFI_PASSWORD\"\r\n", 2000, DEBUG); //connect wi-fi network (replace WIFI_SSID by your Wi-Fi router SSID and WIFI_PASSWORD by its password
  sendData("AT+CIPMUX=1\r\n", 1000, DEBUG); //allow multiple connections
  delay(1000);
  sendData("AT+CIPSERVER=1,PORTNUMBER\r\n", 1000, DEBUG); // start web server on port PORTNUMBER
  delay(1000);
  sendData("AT+CIPSTO=30\r\n", 1000, DEBUG); // SET TIMEOUT TO 30
  delay(500);
}

void loop() {

  if (esp8266.available())  //verify incoming data
  {
    String msg;
    String i;
    if (esp8266.find("+IPD,")) //if there is a message
    {
      i = esp8266.readStringUntil(',');
      msg = esp8266.readString(); //read whole message
      if (msg.indexOf("on LED") >= 0) digitalWrite(10, HIGH);
      else if (msg.indexOf("off LED") >= 0) digitalWrite(10, LOW);
      String closeCommand = "AT+CIPCLOSE=";
      closeCommand += i; // append connection id
      closeCommand += "\r\n";
      sendData(closeCommand, 1000, DEBUG); // close connection
    }
  }
}

//*******************
//Auxiliary functions
//*******************
String sendData(String command, const int timeout, boolean debug)
{
  String response = "";
  esp8266.print(command);
  long int time = millis();
  while ( (time + timeout) > millis())
  {
    while (esp8266.available())
    {
      char c = esp8266.read();
      response += c;
    }
  }
  if (debug)
  {
    Serial.print(response);
  }
  return response;
}