rs232 in C#

charles.leport · Dec 26th 2011

dear,

i use picocom2 module and i want to create a first application in c# but i need to use RS232 to communicate with an other device, have you an example of communication RS232 in C# because i found no document about it

thanks in advance

hpb · Dec 26th 2011

You will find samples by search for class "System.IO.Ports.SerialPort" in the www.

charles.leport · Dec 29th 2011

Thanks for your answer but i find why my application didn't because i used COM1 instead of COM2.
I didn't succed to open COM1 so i thought that it was my code but not.

hpb · Dec 29th 2011

I think by default COM1 is used as serial debug line or for run <ndcucfg.exe>. Switch off these programs makes COM1 available.

charles.leport · Mar 5th 2012

dear,

i use COM2 but i have a problem with the reception.... i read nothing. i try all i found with google read, readline, existing receive event or not but nothing, aybody have an idea. It's strange because an other application wrote in C++ works perfectly!!!! so it's not an hardware problem maybe f&s driver problem?

thanks in advance

fs-support_ZU · Mar 5th 2012

Hello,
how do you test it by using c++?
Can you post your C# code?
I don't think that it is a driver poblem becaus it works in c++.

charles.leport · Mar 5th 2012

i write a simple application on vs2005 with just a text box and a button
As soon as receive anything on com 2 i send the data on the textbox and when i click on the button i send a message to the pc.

I write the application for windows it's works well.
I write the same (same code) for smart device application and picocom.... and just the TX message works (with the button)

this is the code

Code

namespace Testrs232
{
public partial class Form1 : Form
{
string text = "";
public Form1()
{
InitializeComponent();
this.serialPort1.Open();
}
private void serialPort1_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
text = serialPort1.ReadExisting();
this.Invoke(new EventHandler(Actualize));
}
// Process the data received in the full frame buffer and extract.
private void Actualize(object s, EventArgs e)
{
// Assign the value of the plot to the textBox.
this.textBox1.Text = text;
}
private void button1_Click(object sender, EventArgs e)
{
this.serialPort1.WriteLine("test");
}
}
}

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[EDIT from admin: repaired the code section]

fs-support_ZU · Mar 5th 2012

Wath's about your initialisation?
Did you try following with your special setting (http://msdn.microsoft.com/de-d…ialport.datareceived.aspx)?
If it not works, can you read without using an event?

Code

using System;
using System.IO.Ports;
class PortDataReceived
{
public static void Main()
{
SerialPort mySerialPort = new SerialPort("COM1");
mySerialPort.BaudRate = 9600;
mySerialPort.Parity = Parity.None;
mySerialPort.StopBits = StopBits.One;
mySerialPort.DataBits = 8;
mySerialPort.Handshake = Handshake.None;
mySerialPort.DataReceived += new SerialDataReceivedEventHandler(DataReceviedHandler);
mySerialPort.Open();
Console.WriteLine("Press any key to continue...");
Console.WriteLine();
Console.ReadKey();
mySerialPort.Close();
}
private static void DataReceviedHandler(
object sender,
SerialDataReceivedEventArgs e)
{
SerialPort sp = (SerialPort)sender;
string indata = sp.ReadExisting();
Console.WriteLine("Data Received:");
Console.Write(indata);
}
}

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charles.leport · Mar 5th 2012

in visual studio 2005 when you add a serial port in the designer the initialisation is by default 9600 8 1 N.
i use COM2 not COM1 because COM1 is already used by netdcu.
I tried without event and it's the same. I change the dtr state, rts cts it's the same

fs-support_ZU · Mar 5th 2012

Strange! But i can't believe that there is a bug in .NET! But if it works in c++ ... .
Can you check it with VS2008 and .NET3.5?
Did you try following work around by ddl import?

Code

protected IntPtr hPort;
const UInt32 GENERIC_READ= 0x80000000;
const UInt32 GENERIC_WRITE = 0x40000000;
const UInt32 OPEN_EXISTING = 3;
public bool Open(string Port)
{
hPort = CreateFile(Port, GENERIC_READ|GENERIC_WRITE, 0, IntPtr.Zero, OPEN_EXISTING, 0, IntPtr.Zero);
if (hPort == (IntPtr)(-1))
return false;
return true;
}
public void Close()
{
CloseHandle(hPort);
}
private bool Read(ref Byte b)
{
Byte[] Data = new Byte[1];
Int32[] Read = new Int32[1];
if (ReadFile(hPort, Data, 1, Read, IntPtr.Zero) > 0)
{
b = Data[0];
return true;
}
return false;
}
private bool Write(Byte b)
{
Byte[] Data = new Byte[1];
Int32[] Written = new Int32[1];
Data[0] = b;
if(WriteFile(hPort, Data, 1, Written, IntPtr.Zero)>0)
return true;
return false;
}
// ******************************************************************
[DllImport("coredll.dll", EntryPoint = "CreateFileW", SetLastError = true)]
public extern static IntPtr CreateFile(string lpFileName, uint dwDesiredAccess, uint dwShareMode, IntPtr pSecurityAttributes,
uint dwCreationDisposition, uint dwFlagsAndAttributes, IntPtr hTemplateFile);
[DllImport("coredll.dll", EntryPoint = "CloseHandle", SetLastError = true)]
public extern static int CloseHandle(IntPtr hObject);
[DllImport("coredll.dll", EntryPoint = "ReadFile", SetLastError = true)]
public extern static uint ReadFile(IntPtr hObject, Byte[] lpBuffer, uint NumberOfBytesToRead, Int32[] NumberOfBytes,
IntPtr lpOverLapped);
[DllImport("coredll.dll", EntryPoint = "WriteFile", SetLastError = true)]
public extern static uint WriteFile(IntPtr hObject, Byte[] lpBuffer, uint NumberOfBytesToWrite, Int32[] NumberOfBytes,
IntPtr lpOverLapped);

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charles.leport · Mar 5th 2012

sorry but i don't know how to use dll import with serial port, i'm a beginner.
Don't you have just an exemple written in c# for rs232 that you test before with your module like picocom2 ?!!!!! nobody tests it ????

fs-support_ZU · Mar 5th 2012

Sorry, i have no complete source code sample.
Just use dll imports i attached in my previous post and call "Open()", "Read()", "Close()" from your code.
Does this work?

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