C / C++ / MFC

1. Decide where to handle the messages (main frame or other window).
2. Pass the handle of the window to your interrupt service class using the m_hWnd member of your CWnd derived class. The service class should contain a member var for the handle.
3. Add the message definition to a header file (project header file or those of the window class).
4. Add the user message handler to your window class.
5. Call PostMessage from your interrupt handler.

//In the header file
#define	Digital_Event		1
// Message for 1553 interrupts
	afx_msg LRESULT OnDigitalInterrupt(UINT wParam, LONG lParam);

// In the Main MFC file of the application
const UINT WM_INTERRUPT_DIGITAL = WM_APP + 1;
HWND	g_hMainHWND;

BEGIN_MESSAGE_MAP(CDigitalPnPDlg, CDialog)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	// Interrupt for Digital
	ON_MESSAGE(WM_INTERRUPT_DIGITAL, OnDigitalInterrupt)

// In the Dialog Init routine
	g_hMainHWND = this->GetSafeHwnd();

LRESULT CDigitalPnPDlg::OnDigitalInterrupt(UINT wParam, LONG lParam)
{
	/* This routine is called every 20 msec by the interrupt from the
		board. 	*/
	if(wParam == Digital_Event)
		manage_timers();
	return 0;
}


// In the interrupt routin
	/* Arrange for the processing of the 20 msec interrupt in the main application	*/
	PostMessage(g_hMainHWND, WM_INTERRUPT_DIGITAL, Digital_Event, NULL);

enhzflep wrote:

In fact, one of the very reasons I avoided coding windows programs for quite a while was the fact that it was considerably more difficult to write code that would interact with hardware directly.

class CTest1
{
public:
    // This is your callback routine
    static void _DigitalInt(void * pData);

public:
    // This is the method that does the work.
    void DigitalInt(void);
};

void CTest1::_DigitalInt(void * pData)
{
    ((CTest1 *) pData)->DigitalInt();
}

void CTest1::DigitalInt(void)
{
// Do Stuff here.
}