buzzer_test_app.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#include <sys/ioctl.h>
#include <signal.h>

#define BUZZER_DEVICE "/dev/csemad_buzzer"

unsigned char quit = 0;

void user_signal1(int sig)
{
    quit = 1;
}

int main(int argc, char **argv)
{
    int dev;
    unsigned char state = 0;
    unsigned char retval;
    unsigned char data;
    dev = open(BUZZER_DEVICE, O_RDWR);
    
    if (dev < 0) 
    {
        printf("Device open error : %s\n", BUZZER_DEVICE);
        exit(1);
    }
    
    (void)signal(SIGINT, user_signal1);

    printf("Press <ctrl+c> to exit.\n");
    
    while(!quit) 
    {
        if(state != 0) 
        {
            state = 0;
            data = 1;
            retval = write(dev, &data, 1);
            
            if(retval < 0) 
            {
                printf("Write Error!\n");
                return -1;
            }
        } 
        else 
        {
            state = 1;
            data = 0;
            retval = write(dev, &data, 1);
            
            if(retval < 0) 
            {
                printf("Write Error!\n");
                return -1;
            }
        }
        
        sleep(1);
    }
    
    data = 0;
    retval = write(dev, &data, 1);

    printf("Current Buzzer Value : %d\n",data);
    
    close(dev);
    return(0);
}