Raspberry Pi and Windows IOT and SerialPort with Visual Studio

Question

I started example SerialSample, and it works well, but I have a question:

How do I send something to the com port without the use of a button, i.e. directly with the code, for example at application startup or after the occurrence of an event?

Additionally: How to choose a serial on board without a button only when the application is started?

Example from microsoft: SerialSample

Answer 1

I found the solution: - write to serial:

           using (var dataWriter = new DataWriter(serialPort.OutputStream))
            {
                dataWriter.WriteString("what u want to send ");
                await dataWriter.StoreAsync();
                //await dataWriter.FlushAsync();
                dataWriter.DetachStream();
            }

and serial initialization:

public sealed partial class MainPage : Page
{
    private SerialDevice serialPort = null;
    DataWriter dataWriteObject = null;
    DataReader dataReaderObject = null;

    private ObservableCollection<DeviceInformation> listOfDevices;
    private CancellationTokenSource ReadCancellationTokenSource;


    public MainPage()
    {
        this.InitializeComponent();            
        comPortInput.IsEnabled = false;
        sendTextButton.IsEnabled = false;
        listOfDevices = new ObservableCollection<DeviceInformation>();
        ListAvailablePorts();

        InitSerial();
    }
private async void InitSerial()
    {

        string portNameN = "UART0";

        string aqs = SerialDevice.GetDeviceSelector(portNameN);

        var myDevices = await DeviceInformation.FindAllAsync(aqs, null);

        if (myDevices.Count == 0)
        {
            status.Text = "Device not found...";
            return;
        }
        serialPort = await SerialDevice.FromIdAsync(myDevices[0].Id);

        // Configure serial settings
        serialPort.WriteTimeout = TimeSpan.FromMilliseconds(1000);
        serialPort.ReadTimeout = TimeSpan.FromMilliseconds(1000);
        serialPort.BaudRate = 9600;
        serialPort.Parity = SerialParity.None;
        serialPort.StopBits = SerialStopBitCount.One;
        serialPort.DataBits = 8;
        serialPort.Handshake = SerialHandshake.None;

        // Display configured settings
        status.Text = "Serial port configured successfully: ";
        status.Text += serialPort.BaudRate + "-";
        status.Text += serialPort.DataBits + "-";
        status.Text += serialPort.Parity.ToString() + "-";
        status.Text += serialPort.StopBits;
     }