Serial port listen on raspberry pi 2 Windows IoT headless mode - serial-port

Question

I am trying to connect raspberry pi 2 windows IoT using usb to serial ttl module on headless mode. I couldn' t find any working example. I just want o send "hello world" to raspberry pi. Microsoft example is too complicated and also you have to click connect button to send and receive data. I tried to change code but I failed to run example. https://ms-iot.github.io/content/en-US/win10/samples/SerialSample.htm

Answer 1

I made a class for send and receive from serial port
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Windows.Storage.Streams;
using Windows.Devices.SerialCommunication;
using System.Threading;
using Windows.Devices.Enumeration;
namespace OMEGA.Raspberry
{
public delegate void DataRecievedDlg(byte[] data);
class USART
{
#region Private Vars
DataReader dataReaderObject = null;
private CancellationTokenSource ReadCancellationTokenSource;
private uint _baudrate;
private SerialParity _parity;
private SerialStopBitCount _stopBits;
private ushort _dataBits;
#endregion
#region Public Vars
public SerialDevice serialPort { get; private set; }
public event DataRecievedDlg DataRecieved;
#endregion
#region Private Functions
public USART()
{
serialPort = null;
}
private async void Listen()
{
try
{
if (serialPort != null)
{
dataReaderObject = new DataReader(serialPort.InputStream);
// keep reading the serial input
while (true)
{
byte[] x = await ReadAsync(ReadCancellationTokenSource.Token);
if (x.Length > 0)
DataRecieved(x);
}
}
}
catch (Exception ex)
{
if (ex.GetType().Name != "TaskCanceledException")
//{
// CloseDevice();
//}
//else
{
throw new Exception(ex.Message);
}
}
finally
{
// Cleanup once complete
if (dataReaderObject != null)
{
dataReaderObject.DetachStream();
dataReaderObject = null;
}
}
}
private async Task<byte[]> 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;
byte[] bytes = new byte[bytesRead];
if (bytesRead > 0)
dataReaderObject.ReadBytes(bytes);
return bytes;
}
#endregion
#region Public Functions
public void CloseDevice()
{
if (serialPort != null)
{
serialPort.Dispose();
}
serialPort = null;
}
public void StopListening()
{
if (ReadCancellationTokenSource != null)
{
if (!ReadCancellationTokenSource.IsCancellationRequested)
{
ReadCancellationTokenSource.Cancel();
}
}
}
public async Task Initialize(uint baudrate, SerialParity parity, SerialStopBitCount stopBits, ushort dataBits)
{
try
{
string aqs = SerialDevice.GetDeviceSelector();
var dis = await DeviceInformation.FindAllAsync(aqs);
serialPort = await SerialDevice.FromIdAsync(dis[0].Id);
serialPort.WriteTimeout = TimeSpan.FromMilliseconds(1000);
serialPort.ReadTimeout = TimeSpan.FromMilliseconds(1000);
serialPort.BaudRate = baudrate;
serialPort.Parity = parity;
serialPort.StopBits = stopBits;
serialPort.DataBits = dataBits;
serialPort.Handshake = SerialHandshake.None;
_baudrate = baudrate;
_parity = parity;
_stopBits = stopBits;
_dataBits = dataBits;
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
}
public void StartListening()
{
ReadCancellationTokenSource = new CancellationTokenSource();
Listen();
}
public async Task<uint> WriteAsync(byte[] data)
{
DataWriter dataWriter = new DataWriter();
dataWriter.WriteBytes(data);
uint bytesWritten = await serialPort.OutputStream.WriteAsync(dataWriter.DetachBuffer());
return bytesWritten;
}
#endregion
}
}