char c;
String stringa;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(10, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  if(Serial.available()){
    stringa="";
    do{
      if(Serial.available()){
      c=Serial.read();
      if(c != '\n')
      stringa+=c;}
    }while(c != '\n');
    if(stringa=="accenditi")
    digitalWrite(10, HIGH);
    else if(stringa=="spegniti")
    digitalWrite(10, LOW);
  }
}