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Bruce Eitman

Windows CE Musings

<< Windows CE: Developing an API to Access a Driver | Home | Windows CE: Launching an Application when a Network Connects >>

Windows CE: Writing an Application to Test GPIO Pins

Download GPIO Example driver and appplication source code

In previous articles I have developed a driver to access GPIO Pins, Windows CE: Using a Driver to Read/Write Hardware Registers, and a wrapper API for the driver, Windows CE: Developing an API to Access a Driver. Now it is time to use them from an application.

Because the real work is done in the driver, and because we have some simple to use wrapper functions, this application is very simple. It starts by calling the InitGPIOAPI() function, then it sets GPIO Pin 30 to be an output and then toggles the pin high and low.

#include <Windows.h>

#include <GPIO_API.h>

int WINAPI WinMain( HINSTANCE hInstance,

HINSTANCE hPrevInstance,

LPTSTR lpCmdLine,

int nCmdShow)

{

HANDLE hGPIO_API;

DWORD count;

RETAILMSG( 1, (TEXT("Testing GPIO\n")));

hGPIO_API = InitGPIOAPI();

if( hGPIO_API != INVALID_HANDLE_VALUE )

{

SetOutputGPIOPin( hGPIO_API, 30 );

for( count = 0; count < 20; count++ )

{

SetGPIOPin( hGPIO_API, 30 );

RETAILMSG( 1, (TEXT( "set GPIO 30 is %s\r\n"), ReadGPIOPin(hGPIO_API, 30)?TEXT("Set"):TEXT("Clear")));

Sleep( 1000 );

ClearGPIOPin( hGPIO_API, 30 );

RETAILMSG( 1, (TEXT( "clear GPIO 30 is %s\r\n"), ReadGPIOPin(hGPIO_API, 30)?TEXT("Set"):TEXT("Clear")));

Sleep( 1000 );

}

DeinitGPIOAPI( hGPIO_API );

}

RETAILMSG(1,(TEXT("Done\n")));

return 0;

}

Also see the articles in this series at: Windows CE: Developing an API to Access a Driver and Windows CE: Using a Driver to Read/Write Hardware Registers.

Copyright © 2010 – Bruce Eitman

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Sunday, August 01, 2010 7:33 PM

Your Comments.

# re: Windows CE: Writing an Application to Test GPIO Pins
hi

i need use s3c6410 keypad in c# cf

can you help me ?

reza.vatankhah@gmail.com

Left by reza at 5/28/2011 7:58 AM
# re: Windows CE: Writing an Application to Test GPIO Pins
Reza:

I don't know anything about your device/BSP so there isn't much that I can offer you.

Bruce

Left by Bruce Eitman at 6/6/2011 8:38 AM
# re: Windows CE: Writing an Application to Test GPIO Pins
Hey Bruce,

I have been working on Win CE applications for about two weeks. My background is in Linux and application development, so I have basically been learning the enviroment from scratch. I just wanted to thank you for your time and patience in the newsgroups and your own blog. Your information has been invaluable in getting my feet with BSP modification/driver development.

Thanks so much for your time!

Left by William at 6/6/2011 6:41 PM
# re: Windows CE: Writing an Application to Test GPIO Pins
Hi Bruce,
Thanks for your valuable information on Writing Application to access GPIO.I have just started working on WinCE Platform prior to this i was working on linux(Fedora) Plaform. I ahve tried to access GPIO pins on our FreesCale IMX-35 PDK but it failed to load on WinCE.Also i Have not written any driver and Api for this just used headers files and linked specific DLL and LIB file with our application.Please find below the snippet of code i am using to access GPIO:

// GPIO_MFC12Dlg.cpp : implementation file
//
#pragma warning(push)
#pragma warning(disable: 4115 4201 4204 4214)
#include <windows.h>
#include <ceddk.h>
#pragma warning(pop)
#include <types.h>
#include <bsp_cfg.h>
#include <nkintr.h>
#include <Winbase.h>
#include "stdafx.h"
#include "GPIO_MFC12.h"
#include "GPIO_MFC12Dlg.h"
#include "bsp.h"
#include <common_ddk.h>
#include <csp.h>
#include<mx35_ddk.h>
#include<devload.h>
#include<common_gpio.h>

CGPIO_MFC12Dlg::CGPIO_MFC12Dlg(CWnd* pParent /*=NULL*/)
: CDialog(CGPIO_MFC12Dlg::IDD, pParent)
{
m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CGPIO_MFC12Dlg::DoDataExchange(CDataExchange* pDX)
{
CDialog::DoDataExchange(pDX);
}

BEGIN_MESSAGE_MAP(CGPIO_MFC12Dlg, CDialog)
#if defined(_DEVICE_RESOLUTION_AWARE) && !defined(WIN32_PLATFORM_WFSP)
ON_WM_SIZE()
#endif
//}}AFX_MSG_MAP
ON_BN_CLICKED(IDC_BUTTON1, &CGPIO_MFC12Dlg::OnBnClickedButton1)
ON_BN_CLICKED(IDC_BUTTON2, &CGPIO_MFC12Dlg::OnBnClickedButton2)
END_MESSAGE_MAP()

// CGPIO_MFC12Dlg message handlers

BOOL CGPIO_MFC12Dlg::OnInitDialog()

{

CDialog::OnInitDialog();

// Set the icon for this dialog. The framework does this automatically
// when the application's main window is not a dialog
SetIcon(m_hIcon, TRUE); // Set big icon
SetIcon(m_hIcon, FALSE); // Set small icon

// TODO: Add extra initialization here

return TRUE; // return TRUE unless you set the focus to a control
}

#if defined(_DEVICE_RESOLUTION_AWARE) && !defined(WIN32_PLATFORM_WFSP)
void CGPIO_MFC12Dlg::OnSize(UINT /*nType*/, int /*cx*/, int /*cy*/)
{
if (AfxIsDRAEnabled())
{
DRA::RelayoutDialog(
AfxGetResourceHandle(),
this->m_hWnd,
DRA::GetDisplayMode() != DRA::Portrait ?
MAKEINTRESOURCE(IDD_GPIO_MFC12_DIALOG_WIDE) :
MAKEINTRESOURCE(IDD_GPIO_MFC12_DIALOG));
}
}
#endif

static void Write_Gpio()

{
printf("Entered in WRITE_GPIO function \n");

//DDKIomuxSetPinMux(DDK_IOMUX_PIN_EIM_D17,DDK_IOMUX_PIN_MUXMODE_ALT1,DDK_IOMUX_PIN_SION_REGULAR);
DDKIomuxSetPinMux(DDK_IOMUX_PIN_ATA_DATA0, DDK_IOMUX_PIN_MUXMODE_ALT0,DDK_IOMUX_PIN_SION_REGULAR);
Sleep(100);
// Configure GPIO1_3 as a level-sensitive interrupt input

DDKGpioSetConfig(DDK_GPIO_PORT2,13, DDK_GPIO_DIR_IN, DDK_GPIO_INTR_HIGH_LEV);
printf("PIN set Sucessfully ! \n");

//Writing data at pin 3

// for(t=0;t++;t<5)
// {

DDKGpioWriteDataPin(DDK_GPIO_PORT2,13,0);
// Clear interrupt status for GPIO1_3
DDKGpioClearIntrPin(DDK_GPIO_PORT2, 13);

Sleep(1000);
//Writing 1 on GPIO pin 1

DDKGpioWriteDataPin(DDK_GPIO_PORT2,13,1);
printf("Data writen Sucessfully! \n");
// Clear interrupt status for GPIO1_3

Sleep(1000);
DDKGpioClearIntrPin(DDK_GPIO_PORT2,13 );
printf("Interrupt Pin Cleared Sucessfully ! \n");

Sleep(1000);
}
return;

}

void CGPIO_MFC12Dlg::OnBnClickedButton1()
{
// TODO: Add your control notification handler code here
Write_Gpio();

}

void CGPIO_MFC12Dlg::OnBnClickedButton2()
{
// TODO: Add your control notification handler code here
exit(0);
}

Left by Surya Prakash Singh at 7/13/2011 6:23 AM
# re: Windows CE: Writing an Application to Test GPIO Pins
Surya:

You need to use a driver, or the kernel.

Please read this article, and the two reference articles.

Bruce

Left by Bruce Eitman at 7/13/2011 8:24 AM
# re: Windows CE: Writing an Application to Test GPIO Pins
Thanks for reply Bruce,
We didn't get any driver from Freescale, so do we need to write driver by own and use it with our application. we have only got some sets of functions defined in a file and called in some files, from those files i have just copied and used these functions which i have already used in the snippet of code shown above.

Left by Surya Prakash Singh at 7/14/2011 7:49 AM
# re: Windows CE: Writing an Application to Test GPIO Pins
Surya:

Not knowing what the code looks like it is very difficult for me to advise you.

If this is Windows CE 6.0 or newer, you will need to use a driver of the kernel to access the GPIO registers.

Bruce

Left by Bruce Eitman at 7/14/2011 8:37 AM
# re: Windows CE: Writing an Application to Test GPIO Pins
Hi Bruce,

You have an excellent resource here for WinCE developers old and new. Great job and thank you!

I am trying to use your GPIO code for a project, I have made the GPIO_Example part of my OSDesign and it is compiling no problem.

I am trying to access the GPIO functions from an application that I am developing to use under this OSDesign (VS2005). I am getting error

LNK2019: unresolved external symbol "void __cdecl DeinitGPIOAPI(void *)" (?DeinitGPIOAPI@@YAXPAX@Z) referenced in function "public: virtual int __cdecl MFCMeasurePlateDlg::OnInitDialog(void)"

for all the functions.

What can be the issue? Also I wanted to know how can I implement PWM on a selected GPIO pin.

Your input would be greatly appreciated.

Thanks and best regards,

Adnan K

Left by Adnan Khalid at 7/27/2011 1:06 AM
# re: Windows CE: Writing an Application to Test GPIO Pins
Adnan:

Your code is in a C++ file, so you will need to define the function prototypes for the functions and make them C functions.

Bruce

Left by Bruce Eitman at 7/28/2011 8:26 AM
# re: Windows CE: Writing an Application to Test GPIO Pins
Hi Bruce,

You have made a great resource here for WinCE developers new and old. Thank you and keep up the good work!

I have added the GPIO_Example to my OSDesign and it compiled no problem. I am now trying to access the functions via an application I am developing for WinCE6.0 under VS2005. I get the following error on compiling of the application for each function used:

error LNK2019: unresolved external symbol "void __cdecl DeinitGPIOAPI(void *)"

What do you think the issue is? Also I would like you thoughts on implementing PWM on the GPIO.

Thanks and best regards,

Adnan K

Left by Adnan Khalid at 7/28/2011 11:37 PM
# re: Windows CE: Writing an Application to Test GPIO Pins
Hi Bruce,

I have followed the steps and instructions. Everything compiles (both OS and Application), however when I try to run the application, nothing happens, it doesn't even start up or give an error.

I cannot see drivershell in regedit or even the .dll in the windows folder. the driver is not there or loading.

What can the issue be?

Thanks and best regards,

Adnan K

Left by Adnan Khalid at 7/31/2011 3:29 AM
# re: Windows CE: Writing an Application to Test GPIO Pins
Adnan:

Did you add the driver to your OS? It would seem that you did not.

Do you have the debug output?

Bruce

Left by Bruce Eitman at 7/31/2011 8:34 AM
# re: Windows CE: Writing an Application to Test GPIO Pins
Hi Bruce,

Thank you for the response. I have now managed to get the Drivershell.dll and GPIO_API.dll in the Windows directory on the WinCE system.

The issue is still the same, the application does not even start up, no errors.

When I try to deploy via VS2005 I get "No process is on the other end of the pipe."

Thanks,

Adnan K.

Left by Adnan Khalid at 7/31/2011 2:43 PM
# re: Windows CE: Writing an Application to Test GPIO Pins
Adnan:

Does your device have a serial debug port? If so, there may be valuable information being output there.

Bruce

Left by Bruce Eitman at 8/11/2011 8:53 AM

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