60 api / vcom commands appendix, Basic example for setting half/full duplex mode – Hatteland Display HT B22 (Fanless) User Manual
Page 60
60
API / VCOM Commands
Appendix
IND100077-132
Basic Example for setting Half/Full Duplex Mode
Example using Linux, C style.
Note,
ttyS7
has been used as port ID. It may differ depending on your system installation. In any case, simply write
ttyS
x
(where
x
is the number defined by the Operating System automatically) for Virtual COM Port.
#include
#include
#include
#include
#include
#include
int
main(
void
)
{
int
n;
int
f;
struct
termios options;
//Open COM Port
f = open(“/dev/
ttyS7
”, O_RDWR | O_NOCTTY | O_NDELAY);
if
(f == -
1
)
{
perror(“open_port: Unable to open:”);
return
-
1
;
}
else
{
printf(“COM Port Opened!\n”);
fcntl(f, F_SETFL,
0
);
}
//Configure COM Port
tcgetattr(f, &options);
cfsetispeed(&options, B9600);
cfsetospeed(&options, B9600);
options.c_cflag |= (CLOCAL | CREAD);
options.c_cflag &= ~PARENB;
options.c_cflag &= ~CSTOPB;
options.c_cflag &= ~CSIZE;
options.c_cflag |= CS8;
tcsetattr(f, TCSANOW, &options);
//Half Duplex Write
unsigned char
half_duplex_cmd[
9
] = {
0x07,0xFF,0x51,0x44,0x55,0x01,0x0E,0x00,0xFF
};
write(f, half_duplex_cmd,
9
);
printf(“Sent Half Duplex\n”);
//Full Duplex Write
unsigned char
full_duplex_cmd[
9
] = {
0x07,0xFF,0x51,0x44,0x55,0x01,0x0E,0xFF,0x00
};
write(f, full_duplex_cmd,
9
);
printf(“Sent Full Duplex\n”);
//Close COM Port
close(f);
printf(“Finished!\n”);
return
0
;
}