public double AccuracyThreshold {get; set;}

{
    var newSrc = new SerialPortDeviceLocationSource();
    //Specify the COM port the device is connected to
    newSrc.ComPort = "Com3";
    newSrc.BaudRate = 4800;
    newSrc.AntennaHeight = 3;  // meters
                               //fill in other properties as needed

    var props = new DeviceLocationProperties();
    props.AccuracyThreshold = 10;   // meters

    // jump to the background thread
    //Note: Run within a QueuedTask
    //open the device
    DeviceLocationService.Instance.Open(newSrc, props);
}

{
    // Check if a device is connected
    bool isConnected = DeviceLocationService.Instance.IsDeviceConnected();
    if (!isConnected)
        return; // no device connected
                // Get the current device location source
    var src = DeviceLocationService.Instance.GetSource();
    // Check if the source is a SerialPortDeviceLocationSource
    //Set values for the SerialPortDeviceLocationSource
    if (src is SerialPortDeviceLocationSource serialPortSrc)
    {
        var port = serialPortSrc.ComPort;
        var antennaHeight = serialPortSrc.AntennaHeight;
        var dataBits = serialPortSrc.DataBits;
        var baudRate = serialPortSrc.BaudRate;
        var parity = serialPortSrc.Parity;
        var stopBits = serialPortSrc.StopBits;

        // retrieving spatial reference needs the MCT
        var sr = await QueuedTask.Run(() =>
        {
            return serialPortSrc.GetSpatialReference();
        });

    }
    //Get current device location properties being used.
    var dlProps = DeviceLocationService.Instance.GetProperties();
    var accuracy = dlProps.AccuracyThreshold;
}

{
    //Note: Run within QueuedTask
    // Get the current device location properties
    var dlProps = DeviceLocationService.Instance.GetProperties();
    //Change the accuracy threshold
    dlProps.AccuracyThreshold = 22.5; // meters
                                      // Update the properties on the device location source
    DeviceLocationService.Instance.UpdateProperties(dlProps);
}