String voice;
void setup() {
Serial.begin(9600);
pinMode(6, OUTPUT);
pinMode(5, OUTPUT);
}

void loop() {
while(Serial.available()){
  delay(3);
  char c = Serial.read();
  voice+=c;}

if(voice.length() >0){
  Serial.println(voice);
  if(voice == "turn on light")
  {digitalWrite(5, HIGH);}
  else if(voice == "turn off light")
  {digitalWrite(5, LOW);}
  else if(voice == "turn on fan")
  {digitalWrite(6, HIGH);}
  else if(voice == "turn off fan")
  {digitalWrite(6, LOW);}
  else if(voice == "turn on all")
  {digitalWrite(6, HIGH);
  digitalWrite(5, HIGH);}
  else if(voice == "turn off all")
  {digitalWrite(6, LOW);
  digitalWrite(5, LOW);}
  voice = "";}
}