C / C++ / MFC Discussion Boards

How does one access a Serial port using Visual C++ 2008 Express tools.

dk-info9-Nov-09 2:32

9-Nov-09 2:32

Background: I am an embedded 'C' programmer, with no windows development experience other than simple console applications using Win32. I have developed using classes but mostly in Java. Other than the ubiquitous "Hello World" using Windows Forms and C++, I have limited to no windows programming experience.

Problem:I have a project where I need to interface an embedded controller to a windows application. Ultimately I need to translate input from windows controls into a stream of serial characters. This stream is interpreted by the embedded controller to do "stuff". The serial interface here may be a "real" serial port, or through a USB-Serial converter cable.

I don't have the money to buy comm libraries, I am using the Visual Studio 2008 Express because it is free, and unless it is absolutely necessary, I am not interested in learning another language like C# or Visual Basic. It is difficult enough for a 'C' coder in the embedded world to transition into the windows world of C++. I don't understand the implications of using ATL vs. MFC vs CLR vs Win32, so please be gentle.

I have posed this question now a half a dozen other forums and keep getting references to Visual C++ 2005 or 2006 code that will not compile in the .NET vernacular (did I get the nuance correct?) Or admonishments to "Just use ___" (insert any of J#, C#, VB or PHP). What used to be a simple:"fputc(com1, "My String");" is now a multilayered, insulated, managed into obscurity onion of code.

If I understand it correctly, in the Win32 vernacular, there is a serial port class, that can be used to instantiate an object that has methods for determining if a port exists, setting port parameters (like BRPY- Baud rate and parity, and flow control) as well as mapping the "<<" and ">>" operators to accommodate inserting/retrieving objects (like a string) into the stream.

I have yet to see an example of code, written using Win32, that will demonstrate moving a single character to a serial port, using the Visual Studio 2008 toolbox.

I need to lean on the experience of more informed programmers for guidance and direction to help me to the next step. Any help or direction (even if it is an admonishment to "RTFM" as long as the requisite "FM" is given) would be greatly appreciated.

David
Melbourne, Florida

Re: How does one access a Serial port using Visual C++ 2008 Express tools.

David Crow9-Nov-09 3:58

David Crow

9-Nov-09 3:58

dk-info wrote:
Problem:I have a project where I need to interface an embedded controller to a windows application. Ultimately I need to translate input from windows controls into a stream of serial characters. This stream is interpreted by the embedded controller to do "stuff". The serial interface here may be a "real" serial port, or through a USB-Serial converter cable.

See here.

"Old age is like a bank account. You withdraw later in life what you have deposited along the way." - Unknown

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

Re: How does one access a Serial port using Visual C++ 2008 Express tools.

dk-info9-Nov-09 6:33

dk-info

9-Nov-09 6:33

Thank you for the rapid response.

I used a portion of the code you presented to illustrate how to so simple serial output from a Win32 console application. I was able to create a Handle using this code:

#include <iostream>
#include <windows.h>
#include "serialPlay.h"
using namespace std;

int main(void)
{
    HANDLE hCom;
    DWORD dwRet;

    // try to open a serial port
    hCom = ::CreateFile(
       TEXT("\\\\.\\COM1"),	      // filename
       GENERIC_READ | GENERIC_WRITE,  // desired access
       0,                             // exclusive
       NULL,                          // security irrelevant
       OPEN_EXISTING,                 // it has to be there
       FILE_FLAG_OVERLAPPED,          // open asynchronous
     NULL);                           // template file

     if(hCom == INVALID_HANDLE_VALUE) {
	cout << "Cannot open serial port COM1\n";
        return PROGRAM_FAILURE;
     } else {
	// it seems to be open, try to write to it
        WriteFile( hCom, "This is testfile", 16, &dwRet, NULL );
     } // end if no handle creation failure

     return PROGRAM_SUCCESS;
} // end main()

It compiles and runs using Visual C++ in Visual Studio 2008 Express, in a Win32 console project without error, and using another computer and Hyper Terminal set to 9600 Baud, N-8-1 it does indeed transmit the message "This is testfile".

Looking to do more, here is a followup question:
I had to replace the "_T" macro with "TEXT" to resolve a compiler error; what is the "_T" macro?

Thanks again for helping me with this question.

Cheers!
David

Re: How does one access a Serial port using Visual C++ 2008 Express tools.

David Crow9-Nov-09 6:38

David Crow

9-Nov-09 6:38

dk-info wrote:
what is the "_T" macro?

It's declared in the tchar.h header.

Re: How does one access a Serial port using Visual C++ 2008 Express tools.

dk-info11-Nov-09 9:20

dk-info

11-Nov-09 9:20

Thanks for the help, now another question, using only the win32 console, how do you set the com port parameters?

The code you gave is the basis for setting up serial threads (if I understand it correctly) in a windows application. I am not yet ready to try to build a windows application that can interface to a serial port, I would need an example application, tailored for Win32 that will illustrate accessing these comm resources from within the application.

I don't understand enough to solve the compiler errors when I try to piece your excellent tutorial code using the Visual Studio C++ express 2008 environment and Win32.

Would you be so kind as to give a complete example of an application that can send serial characters to a com port and receive them also?

Thanks again for the excellent tutorial,

David

How to prevent screen capture?

semaphore19-Nov-09 2:24

semaphore1

9-Nov-09 2:24

Hello

I am developing window based web application.
I want to put restriction like ,No body can capture my application's screen with any tool .

Please suggest is it possible ?

if Yes,please suggest the way to do this.

Thanks
mahendra

Re: How to prevent screen capture?

mav@octaval9-Nov-09 3:00

mav@octaval

9-Nov-09 3:00

You can't.

--

Miguel A. Vilariño
Software Developer

Re: How to prevent screen capture? [modified]

hxhl959-Nov-09 11:38

hxhl95

9-Nov-09 11:38

Hook the function responsible for screenshotting.

EDIT: oh sorry, I didn't notice the "web application" part of that.

modified on Tuesday, November 10, 2009 11:31 PM

Re: How to prevent screen capture? [modified]

semaphore19-Nov-09 20:48

semaphore1

9-Nov-09 20:48

OK,I changed idea.
Now I am creating desktop application instead of web application which needs to block print screen and screen capture. The print screen can be blocked by registering the hot key but now i am trying to find any message/method called on application when other applications try to grab pixels from its window. I am trying to do this in VC++

Is it possible?

Thanks
Mahendra

modified on Tuesday, November 10, 2009 2:10 AM

Re: How to prevent screen capture?

Midono126-Nov-09 22:00

Midono1

26-Nov-09 22:00

Hi,

any luck? I am tring to do the samething with VC++ too

cheers

Re: How to prevent screen capture?

semaphore127-Nov-09 0:51

semaphore1

27-Nov-09 0:51

Please check this link ,may be helpful for u.

http://www.codeguru.com/forum/showthread.php?p=1893801#post1893801

Re: How to prevent screen capture?

Midono127-Nov-09 4:47

Midono1

27-Nov-09 4:47

any luck

i am trying to do the same here ...........

cheers

Re: How to prevent screen capture?

Ramkrishna Pawar5-Jan-10 8:53

Ramkrishna Pawar

5-Jan-10 8:53

Let me know if anybody is interested in protecting from screen captures. you can contact me at krishnapawar AT gmail DOT com.

Details of Screen Capture Prevention

Gopalakrishna Palem10-Jan-10 1:34

Gopalakrishna Palem

10-Jan-10 1:34

Details on how to prevent screen capture can be found at:
http://gpalem.web.officelive.com/screencap.html#Prevent%20Screen%20Capture[^]

Gopalakrishna
Creator of CFugue Music Library for C++

creating directx texture from raw image data

Andreoli Carlo9-Nov-09 0:58

Andreoli Carlo

9-Nov-09 0:58

My goal:
- display a texture that i can modify in real time (windowing the histogram)

My steps:

1) create an array that will hold my raw information with fast access so i can modify windowing, the array is declared by setting RGB values 8 bit per pixel

// declaring array that will hold raw image
array<Byte> dataArray = gcnew array<Byte>(Length);

2) modify the values of the images and set it to texture

IO::MemoryStream ^fs = gcnew IO::MemoryStream(this->dataArray);
fs->Seek(0,IO::SeekOrigin::Begin);

try {
	mTexture = TextureLoader::FromStream(this->device,
									fs,
									(int)fs->Length,
									768,
									640,
									0,
									Usage::None,
									Format::R8G8B8,
									Pool::Default,
									Filter::None,
									Filter::None,
									0);
}
catch (Direct3D::InvalidDataException ^e) {
	te=e->ToString();
}
fs->Close();

3) display a sprite with texture in it

mSprite->Begin(SpriteFlags::None);
mSprite->Draw(this->mTexture, 
			Rectangle(posx*3,posy*3, 5000,5000),
			Vector3(0.0F, 0.0F, 0.0F),
			Vector3(0.0F, 0.0F, 0.0F), 
			Color::White);
mSprite->End();

the problem is that in this step it die on execution Frown | :(

An unhandled exception of type 'Microsoft.DirectX.Direct3D.Direct3DXException' occurred in Microsoft.DirectX.Direct3DX.dll

Additional information: Error in the application.

Someone can help me point out the problem? thank in advance

TYPE_E_CANTLOADLIBRARY

deadlyabbas9-Nov-09 0:47

deadlyabbas

9-Nov-09 0:47

Hi All,

I tried to build my project in Visual Studio 2008.
I am getting some errors related to TLH files.
I tried to open the type libraries in OLE_VIEW but the some type libraries get easily open where as some gave an error:
Could not decompile selected item
Error loading type library/DLL.
TYPE_E_CANTLOADLIBRARY($80029C4A)

Kindly help me out

Re: TYPE_E_CANTLOADLIBRARY

opedroso221-May-10 9:22

opedroso2

21-May-10 9:22

Hi deadlyabbas,

I am having the same problem.

I was wondering if you ever found a solution.

Thanks,
Osiris

AboutBox

johnjitu9-Nov-09 0:36

johnjitu

9-Nov-09 0:36

Hello everbody

I have small problem in Visual c++ in creating a dialogbox named as Aboutbox,
this is a second dialogbox in my application ,
when i creat the this dialogbox but the following code does not appear in the implementfile.cpp

BOOL CAbout::OnInitDialog()

Should i include myself or Is there another way to do this .

Thanks

waiting for reply.

Re: AboutBox

josda10009-Nov-09 3:47

josda1000

9-Nov-09 3:47

yeah, just make the function yourself. not a big deal.

Re: AboutBox

Stephen Hewitt9-Nov-09 4:18

Stephen Hewitt

9-Nov-09 4:18

There'll be a wizard to add it or you can add in manually.

Steve

Re: AboutBox

johnjitu9-Nov-09 6:25

johnjitu

9-Nov-09 6:25

Thanks to all of u

MFC: Drawing Overlapping Circles

TechAvtar9-Nov-09 0:26

TechAvtar

9-Nov-09 0:26

Hi,

I am trying to draw two circles, which are overlapping . My problem is that the second circle is hiding the first one partially. I want to see both circles completely. Can somebody guide me what parameter should I tweak?

afx_msg void DemoWin::OnPaint ()
{

CPaintDC dc(this);

CRect myRect; /* Define rectangle coordinates */
myRect.top = 0;
myRect.left = 0;
myRect.bottom = 200;
myRect.right = 100;
dc.Ellipse(myRect);

myRect.top = 100;
myRect.left = 50;
myRect.bottom = 200;
myRect.right = 200;
dc.Ellipse(myRect);
}

Thanks
Jacob

Re: MFC: Drawing Overlapping Circles

Cedric Moonen9-Nov-09 1:12

Cedric Moonen

9-Nov-09 1:12

TechAvtar wrote:
My problem is that the second circle is hiding the first one partially. I want to see both circles completely.

What do you mean exactly ? Confused | :confused:

You want the colors of the two circles to be merged ? For instance one circle is white and the other one is white, then the intersection should be gray ?

Cédric Moonen
Software developer

Charting control [v2.0]
OpenGL game tutorial in C++

Re: MFC: Drawing Overlapping Circles

KingsGambit9-Nov-09 1:16

KingsGambit

9-Nov-09 1:16

You can select a NULL brush to the device context before drawing the ellipse.
...
dc.SelectObject(GetStockObject(NULL_BRUSH));
dc.Ellipse(myRect);
...

Re: MFC: Drawing Overlapping Circles

TechAvtar9-Nov-09 1:26

TechAvtar

9-Nov-09 1:26

Thanks .This was I looking for.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.