char val; // Data received from the serial port
long int inByte;

void setup()
{
  //initialize serial communications at a 9600 baud rate
  Serial.begin(9600);
  establishContact();  // send a byte to establish contact until receiver responds
}

void loop()
{
  if (Serial.available() > 0) { // If data is available to read,
    // get incoming byte:
    inByte = Serial.read();

    if (inByte == 'w') {
      //Do Stuff
      delay(100);
    }
    if(inByte == 'a'){
      //Do Stuff
    }
    else {
      Serial.println("Awaiting commands"); //send back a hello world
      delay(10);
    }
  }
}
void establishContact() {
  while (Serial.available() <= 0) {
    Serial.println("A");   // send a capital A
    delay(300);
  }
}