SerialCallResponse_rv1

String mySt;
char myChar = 0;

void setup() {
  // start serial port at 9600 bps:
  Serial.begin(9600);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only
  }

  establishContact();  // send a byte to establish contact until receiver responds
}

void loop() {
  if (Serial.available() > 0) {
    myChar = Serial.read();
    mySt +=myChar;
  }
  if ((mySt.length() >0)&(!Serial.available())) {
    Serial.print(mySt);
    mySt="";
  }
}
void establishContact() {
  while (Serial.available() <= 0) {
    Serial.println("Send me something");
    delay(3000);
  }
}