void loop() {
        if (Serial.available()) {
            digitalWrite(13, HIGH);
        }
        else {
            digitalWrite(13, LOW);
        }
        
	// put your main code here, to run repeatedly: 
	while (Serial.available()) {
		delay(3);  //delay to allow buffer to fill 
		if (Serial.available() > 0) {
			char c = Serial.read();  //gets one byte from serial buffer
			readString += c; //makes the string readString
		}
	}
	
	// handle commands, if any detected
	// if not, repeat what was sent
	if (readString != "" && Serial.available() <= 0) {
		if (readString == "/hello") { // handle the '/hello'
			Serial.println("Hi there, Master!");
		}
		else { // repeat what was said
			Serial.println(readString);
			readString = "";
		}
    }
}