Hi I'm trying to get my mini2440 board to produce 4 pwm signals. I've seen codes that open /dev/pwm and write to it. but how can I make 4 and how can I set which pin to use? I couldn't find any documentation on that does anyone have any? Thank you
I want to run a DC motor using a PWM signal generated by mini2440.Can anyone suggest me how to do that?
Once again I just can offer to use startos. But nobody wants... Sorry.
hello there,
i want to control the pwm using the gui programme...
i also want to start and stop and max and min. the freq. od pwm using this
gui.
i made it but pwm freq does not change
please tell me ... why??
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#include "hello.h"
#include <qlabel.h>
#include <qpushbutton.h>
#include <qtimer.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <linux/fs.h>
#include <errno.h>
#include <string.h>
#include <qobject.h>
#include <fstream>
#include <linux/i2c-dev.h>
#include <string.h>
#include <stdio.h>
#include <linux/fs.h>
#include <termios.h>
#include <stdint.h>
#include <getopt.h>
#include <linux/types.h>
#include <linux/spi/spidev.h>
# include <time.h>
# include <string.h>
# include <sys/time.h>
#define PWM_IOCTL_SET_FREQ 1
#define PWM_IOCTL_STOP 0
int freq=1000;
int fd;
HelloForm::HelloForm( QWidget* parent, const char* name, WFlags fl)
:HelloBaseForm(parent, name, fl)
{
connect(PushButton33,SIGNAL(clicked()),this,SLOT(start()));
connect(PushButton30,SIGNAL(clicked()),this,SLOT(stop()));
connect(PushButton31,SIGNAL(clicked()),this,SLOT(plus()));
connect(PushButton32,SIGNAL(clicked()),this,SLOT(minus()));
}
HelloForm::~HelloForm()
{
}
void HelloForm::start()
{
int fd = open("/dev/pwm", 0);
if (fd < 0) {
status->setText("open pwm_buzzer device");
}
else{
status->setText("start");
}
ioctl(fd, PWM_IOCTL_SET_FREQ, freq);
pwm->setText(QString::number(freq));
//close(fd);
}
void HelloForm::stop()
{
close(fd);
int fd=open("/dev/pwm",0);
ioctl(fd, PWM_IOCTL_STOP);
close(fd);
}
void HelloForm::plus()
{
if(freq<20000)
{
freq+=10;
ioctl(fd,PWM_IOCTL_SET_FREQ,freq);
pwm->setText(QString::number(freq));
}
}
void HelloForm::minus()
{
if(freq>11)
{
freq-=10;
ioctl(fd,PWM_IOCTL_SET_FREQ,freq);
pwm->setText(QString::number(freq));
}
}