message: BLE: clear the Serial1 buffer during startup
diff: int BLE::begin(void)
  {
  +
  + //clear the incoming serial buffer
  + while (_serialPort->available()) _serialPort->read(); //clear the serial buffer associated with the BT unit
  +
  //force into command mode (not needed if already in command mode...but historical Tympan units were preloaded to Data mode instead)
  //myTympan.forceBTtoDataMode(false);
  _serialPort->print("$"); delay(400); _serialPort->print("$$$");
  @@ -37,6 +41,7 @@ int BLE::begin(void)
  void BLE::setupBLE(int BT_firmware)
  {
  +
  int ret_val;
  ret_val = set_BC127_firmware_ver(BT_firmware);
  if (ret_val != BT_firmware) {
  