#include <fcntl.h>
#include <termio.h>
#include <sys/ioctl.h>
#include <sys/time.h>

int mrfd = -1;

int mropen(char *device)
{
struct termio mrtio;

if (mrfd >= 0)
	return mrfd;

if ((mrfd=open(device,O_RDWR | O_NDELAY, 0x666)) < 0)
	return -1;

if (ioctl(mrfd,TCGETA,(char *)&mrtio) == -1)
	return -1;

mrtio.c_iflag = (BRKINT | IGNPAR);

mrtio.c_oflag = 0;

mrtio.c_lflag = 0;

mrtio.c_cflag = (B9600 | CS8 | CLOCAL | CREAD);

mrtio.c_cc[VMIN] = 0;
mrtio.c_cc[VTIME] = 1;

if ((ioctl(mrfd,TCSETA,(char *)&mrtio)) == -1)
	return -1;

return mrfd;
}

int mrclose()
{
if (mrfd < 0)
	return -1;

close(mrfd);
mrfd = -1;
}

float mrpos(int point)
{
char bufout[15], bufin[25];
double pos;
int i, iread, iwrite;
long start_usec, delta_usec;
struct timeval tval;
struct timezone tzone;

sprintf(bufout,"<R%c",point+'A');
strcpy(bufin,"                    ");
iwrite = write(mrfd,bufout,3);
gettimeofday(&tval, &tzone);
start_usec = tval.tv_usec;
/*
usleep(550000L);
*/

i = 0;
do
	{
	iread=read(mrfd,&bufin[i],20);
	if (iread > 0)
		i += iread;
	if (bufin[i-1] == '\r' && i)
		{
		sscanf(bufin,"%lf",&pos);
		return pos;
		break;
		}
	gettimeofday(&tval, &tzone);
	delta_usec = tval.tv_usec - start_usec;
	if (delta_usec < 0)
		delta_usec += 1000000L;
	} while (delta_usec < 750000L);

/*
while((iread=read(mrfd,&bufin[i],20)) > 0)
	{
	i += iread;
	}

if (i)
	{
	sscanf(bufin,"%lf",&pos);
	}
else
	{
	pos = 999.99999;
	}
*/

pos = 999.99999;
return pos;
}