void ledDisplayExist()
{
    char msg[]={'\0', '\0', '\0', '\0', '\0', '\1', 'Z', '0', '0', '\2', 'H', 'B', '\4'  };
    int length = sizeof(msg); 
    writeopen(msg, length);
    readopen();
}

int writeopen(char msg[], int size)
{
    printf("write\n");
    int fd1;
    int wr;
    fd1 = open(ledisplay, O_RDWR | O_NOCTTY | O_NDELAY );
    if (fd1 == -1)
    {
        fprintf(stderr, " %s open_port: Unable to open %s\n", strerror(errno), ledisplay);
    }
    else
    {
        fcntl(fd1, F_SETFL, 0);
        
        wr=write(fd1, msg, size);
        if (wr < 0)
            fputs("write() of n bytes failed!\n", stderr);
        close(fd1);
    }
    return (fd1);
} 

int readopen()
{
    printf("read\n");
    int fd1;
    int rd;
    char *buff=NULL;
    fd1 = open(ledisplay, O_RDONLY | O_NOCTTY | O_NDELAY );
    if (fd1 == -1)
    {
        fprintf(stderr, "%s open_port: Unable to open %s\n", strerror(errno), ledisplay); 
    }
    else
    {
        fcntl(fd1, F_SETFL, 0);
        printf(" Port 1 has been sucessfully opened and %d is the file descriptor\n",fd1);
        rd=read(fd1, buff, 30);
        printf(" Bytes recieved are %d \n",rd);
        close(fd1);
    }
    return (fd1);
}