        stop_beep_ms = millis() + arg;
        btSerial.println("OK");
        break;
-       
+
      case 'K': // read knob pos
        char resp[5];
        snprintf(resp, 5, "%04d", knob_pos);
        btSerial.println(resp);
        break;
-       
+
      case 'P': // ping!
        btSerial.println("OK");
        break;
-       
+
       default:
         Serial.println("Got garbage command!");
         Serial.println(cmd_buf);
-   }  
+   }
    memset(cmd_buf, 0, cmd_buf_len);
 }


void setup()
{
  pinMode(PANEL_PIN, OUTPUT);  
  pinMode(RED_PIN, OUTPUT);  
  pinMode(GREEN_PIN, OUTPUT);  
  pinMode(BLUE_PIN, OUTPUT);  
  pinMode(SPEAKER_PIN, OUTPUT);
  digitalWrite(PANEL_PIN, LOW);
  digitalWrite(RED_PIN, LOW);
  digitalWrite(GREEN_PIN, LOW);
  digitalWrite(BLUE_PIN, LOW); 
  Serial.begin(115200);
  btSerial.begin(9600);
}

/*
 * The Space Probe firmware is a very thin stub program, which speaks a
 * simple serial command/response protocol.
 *
 * All numbers <X> are transmitted as 4-digit decimal integers, regardless of scale.
