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
await QueuedTask.Run(() =>
{
  //open the device
  DeviceLocationService.Instance.Open(newSrc, props);
});

bool isConnected = DeviceLocationService.Instance.IsDeviceConnected();

var src = DeviceLocationService.Instance.GetSource();

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();
  });

}
var dlProps = DeviceLocationService.Instance.GetProperties();
var accuracy = dlProps.AccuracyThreshold;

await QueuedTask.Run(() =>
{
  var dlProps = DeviceLocationService.Instance.GetProperties();
  //Change the accuracy threshold
  dlProps.AccuracyThreshold = 22.5; // meters

  DeviceLocationService.Instance.UpdateProperties(dlProps);
});