mini2440之--pwm程序

如图所示，图中用到了:PixmapLabel,TextLabel,LCDNumber,GroupBox,PushButton组件

pwm.h

#ifndef MYHELLOFORM_H

#define MYHELLOFORM_H

#include "pwm_base.h"

#include <qpixmap.h>

class MyPwmForm : public PwmBaseForm

{ 

	Q_OBJECT

	public:

	    	MyPwmForm( QWidget* parent = 0, const char* name = 0, WFlags fl = 0 );

	    	virtual ~MyPwmForm();

	    	//const QPixmap *eddy;

		int freq;

		//int fd;

	private slots:

	    	void buzzInc();

	    	void buzzDec();

		void buzzON();

	    	void buzzOFF();

};

#endif // MYHELLOFORM_H

pwm.cpp

#include "pwm.h"

#include <qlabel.h>

#include <qlcdnumber.h>

#include <qpushbutton.h>

#include <qbutton.h>

#include <qtopia/qpeapplication.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <stdio.h>

#include <termios.h>

#include <unistd.h>

#include <stdlib.h>

#include <sys/ioctl.h>

static int fd;

#define PWM_IOCTL_SET_FREQ		1

#define PWM_IOCTL_STOP			2

MyPwmForm::MyPwmForm( QWidget* parent, const char* name, WFlags fl)

	    :PwmBaseForm(parent, name, fl)

{

	fd = -1;

	freq = 1000;

	LCDNumber1->setDecMode();

	LCDNumber1->display(freq);

    PushButton1->setEnabled( 0 );

    PushButton2->setEnabled( 0 );

    //PushButton1->show();

    //PushButton2->hide();

	connect(PushButton1,SIGNAL(clicked()),this,SLOT(buzzInc()));

	connect(PushButton2,SIGNAL(clicked()),this,SLOT(buzzDec()));

	connect(PushButton3,SIGNAL(clicked()),this,SLOT(buzzON()));

	connect(PushButton4,SIGNAL(clicked()),this,SLOT(buzzOFF()));

}

MyPwmForm::~MyPwmForm()

{

	buzzOFF();

}

static void close_buzzer(void)

{

	if (fd >= 0) {

		::ioctl(fd, PWM_IOCTL_STOP);

		::close(fd);

		fd = -1;

	}

}

static void set_buzzer_freq(int freq)

{

    // this IOCTL command is the key to set frequency

    int ret = ::ioctl(fd, PWM_IOCTL_SET_FREQ, freq);

    if(ret < 0) {

	::perror("set the frequency of the buzzer");

	::exit(1);

    }

}

void MyPwmForm::buzzON()

{

    fd = ::open("/dev/pwm", 0);

    if (fd < 0) {

	::perror("open pwm_buzzer device");

	::exit(1);

    }

    set_buzzer_freq(freq);

    LCDNumber2->display(fd);

    // any function exit call will stop the buzzer

    ::atexit(close_buzzer);

    PushButton1->setEnabled( 1 );

    PushButton2->setEnabled( 1 );

}

void MyPwmForm::buzzOFF()

{

    int ret = ::ioctl(fd, PWM_IOCTL_STOP);	//PWM_IOCTL_STOP= 2

    //int ret = ::ioctl(fd, 2);

    LCDNumber2->display(fd);

    if(ret < 0) {

	::perror("stop the buzzer");

	::exit(1);

    }

    ::close(fd);

    PushButton1->setEnabled( 0 );

    PushButton2->setEnabled( 0 );

    //::exit(0);	// exit the program directly

}

void MyPwmForm::buzzInc()

{

    if( freq < 20000 )

        freq += 10;

    LCDNumber1->display(freq);

    set_buzzer_freq(freq);

}

void MyPwmForm::buzzDec()

{

    if( freq > 11 )

        freq -= 10 ;

    LCDNumber1->display(freq);

    set_buzzer_freq(freq);

}