Linux C Serial Programming __HTML5

arch/arm/include/asm/termbits.h struct Termios {tcflag_t c_iflag;		/* Input Mode Flags * * tcflag_t C_oflag;		/* Output Mode flags */tcflag_t C_cflag;		/* Control Mode Flags */tcflag_t C_lflag;			/* Local Mode Flags */cc_t c_line;		/* Line Discipline * * cc_t C_CC[NCCS];
/* Control characters */};
The setting of the serial port is mainly to set up the members of the struct Termios structure/** *s3c6410 serial_test * Test when the application runs in the background./serial_test &/#include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include & lt;fcntl.h>//File control definition #include <termios.h>//terminal control definition #include <errno.h> #define DEVICE "/dev/s3c2410_

serial0 "int serial_fd = 0; Open the serial port and initialize the settings init_serial (void) {serial_fd = open (DEVICE, O_RDWR | O_noctty |
	O_ndelay);
		if (SERIAL_FD < 0) {perror ("open");
	return-1;
	
	}//serial port main set structure Termios <termios.h> struct termios options; /**1.
	The TCGETATTR function is used to obtain terminal-related parameters. * Parameter FD is a terminal file descriptor, and the returned result is stored in the Termios structure/tcgetattr (SERIAL_FD, &options); /**2. Modify the obtained parameters * * Options.c_cflag |= (clocal | Cread)//Set control mode state, local connection, receive enable to Options.c_cflag &= ~csize;//character length, before setting data bits must screen this bit options.c_cflag &= ~crtscts;// No hardware flow control Options.c_cflag |= CS8;//8 bit data length Options.c_cflag &= ~cstopb;//1 bit stop bit options.c_iflag |= ignpar;//no parity bit option S.c_oflag = 0; Output mode Options.c_lflag = 0; Do not activate terminal mode Cfsetospeed (&options, B115200);//Set baud rate/**3.
	
	Set new properties, Tcsanow: All changes immediately take effect/Tcflush (SERIAL_FD, Tciflush);//Overflow data can be received, but not read tcsetattr (SERIAL_FD, Tcsanow, &options);
return 0;
	/** * Serial Port Send data * @fd: Serial descriptor * @data: Data to be sent * @datalen: Data length */int uart_send (int fd, char *data, int datalen) {int len = 0;
	Len = Write (fd, data, datalen);//Actual write length if (len = = datalen) {return len;
	else {Tcflush (fd, Tcoflush);//tcoflush refreshes the written data but does not transfer return-1;
return 0;
	/** * Serial port receive data * Request to start, send ASCII file on PC side/int uart_recv (int fd, char *data, int datalen) {int len=0, ret = 0;
	Fd_set Fs_read;
	
	struct Timeval tv_timeout; Fd_zero (&fs_read);
	Fd_set (FD, &fs_read);
	Tv_timeout.tv_sec = (10*20/115200+2);
	
	tv_timeout.tv_usec = 0;
	ret = Select (fd+1, &fs_read, NULL, NULL, &tv_timeout);
	printf ("ret =%d\n", ret);
		If 0 is returned, the representation exceeds the timeout time before the descriptor state changes, and the error returns-1 if (Fd_isset (FD, &fs_read)) {len = read (fd, data, datalen);
		printf ("Len =%d\n", Len);
	return Len;
		else {perror ("select");
	return-1;
return 0;

	int main (int argc, char **argv) {init_serial ();
	Char buf[]= "Hello World";
	Char buf1[10];
	Uart_send (SERIAL_FD, buf, 10);

	printf ("\ n");
	
	
	Uart_recv (SERIAL_FD, BUF1, 10);
	printf ("UART receive%s\n", BUF1);
	Close (SERIAL_FD);
return 0; }