size_t UpdaterClass::writeStream(Stream &data) {
    size_t written = 0;
    size_t toRead = 0;
    if(hasError() || !isRunning())
        return 0;

    if(!_verifyHeader(data.peek())) {
#ifdef DEBUG_UPDATER
        printError(DEBUG_UPDATER);
#endif
        _reset();
        return 0;
    }
    unsigned long timeout = millis();
    if (_progress_callback) {
        _progress_callback(0, _size);
    }
    if(_ledPin != -1) {
        pinMode(_ledPin, OUTPUT);
    }

    while(remaining()) {
        if(_ledPin != -1) {
            digitalWrite(_ledPin, _ledOn); // Switch LED on
        }
        size_t bytesToRead = _bufferSize - _bufferLen;
        if(bytesToRead > remaining()) {
            bytesToRead = remaining();
        }
        toRead = data.readBytes(_buffer + _bufferLen,  bytesToRead);
        if(toRead == 0) { //Timeout
          if (millis() - timeout > 60000) {
            _currentAddress = (_startAddress + _size);
            _setError(UPDATE_ERROR_STREAM);
            _reset();
            return written;
          }
          delay(100);
        } else {
          timeout = millis();
        }
        if(_ledPin != -1) {
            digitalWrite(_ledPin, !_ledOn); // Switch LED off
        }
        _bufferLen += toRead;
        if((_bufferLen == remaining() || _bufferLen == _bufferSize) && !_writeBuffer())
            return written;
        written += toRead;
        if(_progress_callback) {
            _progress_callback(progress(), _size);
        }
        yield();
    }
    if(_progress_callback) {
        _progress_callback(progress(), _size);
    }
    return written;
}