Wiimote Power Button

I'd like to add the following functionality to my apps: When the power button is pressed on the wii remote, the wii turns itself off. Looking through the wiiuse and wpad headers I was unable find support for the power button.

Thanks in advance for any and all help,
Arikado

You should be able to use the Wii remote power button with the current release of libogc ( 1.7.0 )

Straight from wpad.h:

void WPAD_SetPowerButtonCallback(WPADShutdownCallback cb);

typedef void (*WPADShutdownCallback)(s32 chan);

The usage is pretty much like SYS_SetResetCallback() and SYS_SetPowerCallback(), except that the callback function must have a s32 as parameter. This is useful if you only want a certain wii remote to be able to shut down the Wii.

So if you had a callback function like this:

// WPADShutdownCallback 
void doPadPowerOff( s32 chan )
{	
	if ( chan == WPAD_CHAN_0 )
		SYS_ResetSystem( SYS_POWEROFF, 0, 0 );

	return;
}

You'd simply add this line somewhere to your main function to make it work.

WPAD_SetPowerButtonCallback( doPadPowerOff );

I hope this helps.



Edited 1 time(s). Last edit at 12/07/2008 11:43PM by Botskiz.

Thank you for your reply.

I used your code in my app exactly as you posted it. Unfortunately, when I press the power button my app freezes. Do you have any further suggestions?



Edited 1 time(s). Last edit at 12/19/2008 04:41PM by Arikado.

You can't do the power off in the callback itself, or it'll freeze. Use the callback to set a flag, and check that flag.

do it like this:

WPAD_SetPowerButtonCallback( triggerPowerOff );

// WPADShutdownCallback
void triggerPowerOff( s32 chan )
{
powerOffRequested = true;
}

...
in your main loop:
if(powerOffRequested)
{
SYS_ResetSystem( SYS_POWEROFF, 0, 0 );
}



Edited 1 time(s). Last edit at 12/19/2008 07:30PM by Tantric.

Hmm, I'm not sure why it freezes. But you could try using the callback functions to set some poweroff / reset flags, terminate your main loop if one of these flags is set, and reset or shut down the Wii after that. That's the way I usually do it, and I've never encountered any freezing.

Edit: Bah, I'm too slow. Tantric already covered it :)

// Replaced "<" with "(" here to make it work with the forums.
#include (iostream>
#include (gccore.h>
#include (wiiuse/wpad.h>

using namespace std;

bool bPowerOff = false;	// Poweroff flag.
bool bReset = false;		// Reset flag.

//====================================================================
//	Reset callback function.
//====================================================================
void doSystemReset( void )
{
	bReset = true;
	return;
}

//====================================================================
//	PowerOff callback function.
//====================================================================
void doPowerOff( void )
{
	bPowerOff = true;
	return;
}

//====================================================================
//	PowerOff callback function for the Wii Remote power button.
//====================================================================
void doPadPowerOff( s32 chan )
{
	if ( chan == WPAD_CHAN_0 )
		bPowerOff = true;
	return;
}

//====================================================================
//	Main program.
//====================================================================
int main ( int* argc, char** argv )
{
	// Initialise the video system, etc. here.
	// ...

	// Set Reset and Shutdown Callbacks.
	SYS_SetResetCallback( doSystemReset );
	SYS_SetPowerCallback( doPowerOff );
	WPAD_SetPowerButtonCallback( doPadPowerOff );

	// Run the main loop.
	while ( !bReset && !bPowerOff )
	{
		// Do whatever you want your programme to do here.
		// ...
	}
	
	// Reset the system.
	if ( bReset )
		SYS_ResetSystem( SYS_RESTART, 0, 0 );
		
	// Shut the system down.
	if ( bPowerOff )
		SYS_ResetSystem( SYS_POWEROFF, 0, 0 );
	
	return 0;
}

Edited 1 time(s). Last edit at 12/19/2008 07:39PM by Botskiz.

I don't think you need to use a return at the end of each callback.

I don't know why it's not working, your code looks a lot like the one I added in the Developer tips: [wiibrew.org]



Edited 1 time(s). Last edit at 12/19/2008 10:05PM by Crayon.

I get nothing but instant crashes too. Here's my code:

controls.c

static signed int shutdownType = -1; /* Not 0 as ogc/system.h uses that for SYS_RESTART */

static void WiiResetCB(void) {
    shutdownType = SYS_RESTART;
}

static void WiiPowerCB(void) {
    shutdownType = SYS_POWEROFF;
}

static void WiimotePowerCB(int chan) {
    shutdownType = SYS_POWEROFF;
}

extern void Init_Controllers(void) {
    /* Irrelevant code removed */
    
    SYS_SetResetCallback(WiiResetCB);
    SYS_SetPowerCallback(WiiPowerCB);
    WPAD_SetPowerButtonCallback(WiimotePowerCB);

    /* Irrelevant code removed */
}

extern void Check_Controllers(void) {
    /* Irrelevant code removed */

    if (shutdownType != -1) {
        Shutdown(shutdownType);
    }

    /* Irrelevant code removed */
}

main.c

extern void Shutdown(const signed int shutdownType) {
    /* Shutdown various things before exit */
    SYS_ResetSystem(shutdownType, 0, 0);
}

Init_Controllers() is called during startup, and Check_Controllers() is called once per frame. The Shutdown(...) function is called from within the app elsewhere too, and it exits cleanly. If I press the power or reset buttons though, instant crash... any ideas suggestions?

Edit: Forgot to mention that if I remove

if (shutdownType != -1) {
    Shutdown(shutdownType);
}

from Check_Controllers() I still get instant crash when I press power or reset.



Edited 2 time(s). Last edit at 02/15/2009 06:44AM by DrTwox.

DrTwox: Here is how I was able to fix my code.

I put this globally:

bool shutdown = false; //If true shotdown the wii

// WPADShutdownCallback 
    void doPadPowerOff(s32 chan){	
	
	if(chan == WPAD_CHAN_0)
		shutdown = true;

	return;
    }

Put this somewhere in your code. You only need to call it once after WPAD_Init();

WPAD_SetPowerButtonCallback(doPadPowerOff);//Set up power button

And then put this in any loops that need it:

if(shutdown == true)
SYS_ResetSystem( SYS_POWEROFF, 0, 0 );

NOTE: This code copied directly out of my WiiBreaker source code. I made no changes to it in copying and pasting it.

Thanks for the help Arikado!

However, I don't see any functional difference between what you've suggested (and previous posts) to what I'm doing... yet mine crashes instantly when the callback functions are triggered. I must be missing/overlooking something obvious, but I just can't see it!

You cant call SYS_ResetSystem() in the callback function. I dont know why. So I just used a bool instead. Sure, its an extra step but at least it works.