public PressureTempAltitudeUpdater(I2CBus bus, int sigFigs = 4, int delay = 30000)
        {
            _bmpSensor    = new Bmp180(bus);
            _dataArray    = new byte[_dataCount + _metaDataCount + _timeDataCount];
            _dataArray[0] = (byte)PacketType.StartByte; // start bit = 0xff
            _dataArray[1] = (byte)PacketType.BmpDump;

            _delay     = delay;
            _precision = (int)Math.Pow(10, sigFigs - 1);

            _workItem = new WorkItem(BmpUpdater, ref _dataArray, true, true, true);

            _bmpSensor.Init();
        }