User`s manual

UC-7400-LX Plus User’s Manual Programmer’s Guide
5-10
struct termios term;
int fd, speed;
fd = open(“/dev/ttyM0”, O_RDWR);
tcgetattr(fd, &term);
if ( (term.c_cflag & (CBAUD|CBAUDEX)) != B4000000 ) {
// follow the standard termios baudrate define
} else {
ioctl(fd, MOXA_GET_SPECIAL_BAUD_RATE, &speed);
}
Baudrate inaccuracy
Divisor = 921600/Target Baudrate. (Only Integer part)
ENUM = 8 * (921600/Targer - Divisor) ( Round up or down)
Inaccuracy = (Target Baudrate – 921600/(Divisor + (ENUM/8))) * 100%
E.g.,
To calculate 500000 bps
Divisor = 1, ENUM = 7,
Inaccuracy = 1.7%
*The Inaccuracy should less than 2% for work reliably.
Special Note
1. If the target baudrate is not a special baudrate (e.g. 50, 75, 110, 134, 150, 200, 300, 600, 1200,
1800, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 230400, 460800, 921600), the termios
cflag will be set to the same flag.
2. If you use stty to get the serial information, you will get speed equal to 0.
LCM
The UC-7400-LX Plus only supports text mode display, with screen size of 16 cols by 8 rows. The
device node is /dev/lcm. See the examples given below. We provide a private struct defined as
follows:
typedef struct lcm_xy {
int x; // col value, the arrange is 0 – 15
int y; // raw value, the arrange is 0 – 1
} lcm_xy_t;
Examples
int ioctl(fd, IOCTL_LCM_GOTO_XY, lcm_xy_t *pos);
Move the cursor position to the x(col),y(raw) position. Argument 3 is the new position value.
int ioctl(fd, IOCTL_LCM_CLS, NULL);
Clears the LCM display.
int ioctl(fd, IOCTL_LCM_CLEAN_LINE, NULL);
To change one line to all spaces in the current row, and move the cursor to the 0 column of this
row.
int ioctl(fd, IOCTL_LCM_GET_XY, lcm_xy_t *pos);
Get the current cursor position. The value will be returned in argument 3.
int ioctl(fd, IOCTL_LCM_BACK_LIGH_ON, NULL);
Turns the LCM backlight on.
int ioctl(fd, IOCTL_LCM_BACK_LIGHT_OFF, NULL);