serial read string led blink

read_string_led.io

String readString;
String secret = "led";
String on = "on";
String off = "off";
int led = 13;


void setup() {
  Serial.begin(9600);
  Serial.println("Insert the password to blink the led!!");
}

void loop() {

  while (Serial.available()) {
    delay(2);  //delay to allow byte to arrive in input buffer
    char c = Serial.read();
    readString += c;
    readString.trim();
  }

  if (readString.length() >0) {
    Serial.println(readString);


    if(secret == readString)  {
      Serial.println("Unl0ck3d!!");
      digitalWrite(led, HIGH);
      delay(1000);
      digitalWrite(led, LOW);
    }

    if(on == readString)  {
      Serial.println("L3d 0n!!");
      digitalWrite(led, HIGH);
      delay(1000);
    }

    if(off == readString)  {
      Serial.println("L3d 0ff!!");
      digitalWrite(led, LOW);
      delay(1000);
    }
    
    readString="";
  }
}