private async void ListAvailablePorts()
{
bool done = false;
try
{
string aqs = SerialDevice.GetDeviceSelector();
var dis = await DeviceInformation.FindAllAsync(aqs);
listofDevices.Clear();
if (numDevices != 0)
{
for (int i = 0; i < numDevices; i++)
{
if ((dis[i].Name.Contains("USB")) || (dis[i].Id.Contains("FTDI")))
this.listofDevices.Add(dis[i]);
}
//User selects the USB Serial device from the list
            DeviceListSource.Source = this.listofDevices;
comPortInput.IsEnabled = true;
ConnectDevices.SelectedIndex = -1;
//Actual code (see GitHub repository) here contains code to automatically connect
// ..if device Id (disi.Id is listed in the Json Configuration data.
// .. or if only one device connect to it.
        }
}
catch (Exception ex)
{
}
}

public async Task<bool> ConnectSerial(DeviceInformation entry)
{
bool ret = false;
try
{
serialPort = await SerialDevice.FromIdAsync(entry.Id);
if (serialPort == null)
{;
return false;
}
// Configure serial settings
        serialPort.WriteTimeout = TimeSpan.FromMilliseconds(1000);
serialPort.ReadTimeout = TimeSpan.FromMilliseconds(1000);
serialPort.BaudRate = MainPage.cBAUD;
serialPort.Parity = SerialParity.None;
serialPort.StopBits = SerialStopBitCount.One;
serialPort.DataBits = 8;
// Create cancellation token object to close I/O operations when closing the device
        ReadCancellationTokenSource = new CancellationTokenSource();
ret = true;
}
catch (Exception ex)
{
}
return ret;
}

public async void SendCh(char  ch)
{
string msg = "" + ch;
....
// Create the DataWriter object and attach to OutputStream
    dataWriteObject = new DataWriter(serialPort.OutputStream);
//Launch the WriteAsync task to perform the write
    await WriteAsync(msg);
...
}
private async Task WriteAsync(string msg)
{
Task<UInt32> storeAsyncTask;
if (msg.Length != 0)
{
// Load the text from the sendText input text box to the dataWriter object
        dataWriteObject.WriteString(msg);
// Launch an async task to complete the write operation
        storeAsyncTask = dataWriteObject.StoreAsync().AsTask();
UInt32 bytesWritten = await storeAsyncTask;
}
else
{
}
}

private async void Listen()
{
ReadCancellationTokenSource = new CancellationTokenSource();
try
{
if (serialPort != null)
{
dataReaderObject = new DataReader(serialPort.InputStream);
// keep reading the serial input
            while (true)
{
await ReadAsync(ReadCancellationTokenSource.Token);
}
}
}
catch (Exception ex)
{
}
finally
{
// Cleanup once complete
    }
}

private async Task ReadAsync(CancellationToken cancellationToken)
{
Task<UInt32> loadAsyncTask;
uint ReadBufferLength = 1024;
// If task cancellation was requested, comply
    cancellationToken.ThrowIfCancellationRequested();
// Set InputStreamOptions to complete the asynchronous read operation when one or more bytes is available
    dataReaderObject.InputStreamOptions = InputStreamOptions.Partial;
// Create a task object to wait for data on the serialPort.InputStream
    loadAsyncTask = dataReaderObject.LoadAsync(ReadBufferLength).AsTask(cancellationToken);
// Launch the task and wait
    UInt32 bytesRead = await loadAsyncTask;
if (bytesRead > 0)
{
try
{
byte bytes  = new byte[bytesRead];
dataReaderObject.ReadBytes(bytes);
string currenbtRecvdText = Encoding.UTF8.GetString(bytes);
...
...
}
catch (Exception ex)
{
}
}
}

setup()
{
Serial.begin(9600);
while (!Serial)
{
}
Serial.print((char)StartedSignal);
}

void loopUSBSerial() {
thisByte = Serial.peek();
if (thisByte != -1)
{
thisByte = Serial.read();
//Each char is interpretted as byte representing a keypress
//The byte is the id of button pressed + ' ' (so are printable
    switch (thisByte)
{
}
}