uart test

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<fcntl.h>
#include<unistd.h>
#include<termios.h>
#include<string.h>


int set_opt(int fd,int nSpeed, int nBits, char nEvent, int nStop)
{
struct termios newtio,oldtio;
if  ( tcgetattr( fd,&oldtio)  !=  0) { 
perror("SetupSerial 1");
return -1;
}
bzero( &newtio, sizeof( newtio ) );
newtio.c_cflag  |=  CLOCAL | CREAD;
newtio.c_cflag &= ~CSIZE;


switch( nBits )
{
case 7:
newtio.c_cflag |= CS7;
break;
case 8:
newtio.c_cflag |= CS8;
break;
}


switch( nEvent )
{
case 'O':
newtio.c_cflag |= PARENB;
newtio.c_cflag |= PARODD;
newtio.c_iflag |= (INPCK | ISTRIP);
break;
case 'E': 
newtio.c_iflag |= (INPCK | ISTRIP);
newtio.c_cflag |= PARENB;
newtio.c_cflag &= ~PARODD;
break;
case 'N':  
newtio.c_cflag &= ~PARENB;
break;
}


switch( nSpeed )
{
case 2400:
cfsetispeed(&newtio, B2400);
cfsetospeed(&newtio, B2400);
break;
case 4800:
cfsetispeed(&newtio, B4800);
cfsetospeed(&newtio, B4800);
break;
case 9600:
cfsetispeed(&newtio, B9600);
cfsetospeed(&newtio, B9600);
break;
case 115200:
cfsetispeed(&newtio, B115200);
cfsetospeed(&newtio, B115200);
break;
case 460800:
cfsetispeed(&newtio, B460800);
cfsetospeed(&newtio, B460800);
break;
default:
cfsetispeed(&newtio, B9600);
cfsetospeed(&newtio, B9600);
break;
}
if( nStop == 1 )
newtio.c_cflag &=  ~CSTOPB;
else if ( nStop == 2 )
newtio.c_cflag |=  CSTOPB;
newtio.c_cc[VTIME]  = 0;
newtio.c_cc[VMIN] = 0;
tcflush(fd,TCIFLUSH);
if((tcsetattr(fd,TCSANOW,&newtio))!=0)
{
perror("com set error");
return -1;
}
// printf("set done!\n\r");
return 0;
}


int main(void)
{
int fd1,fd2,nset1,nset2,nread;
char buf[100];
char buf1[1];
char *buff = "Hello\n\r";


fd1 = open( "/dev/ttySAC0", O_RDWR);
if (fd1 == -1)
exit(1);


fd2 = open( "/dev/ttySAC1", O_RDWR);
if (fd2 == -1)
exit(1);


nset1 = set_opt(fd1, 115200, 8, 'N', 1);
if (nset2 == -1)
exit(1);


nset2 = set_opt(fd2, 4800, 8, 'N', 1);
if (nset2 == -1)
exit(1);


while (1)
{
nread = read(fd2, buf, 1);
if (nread > 0)
write(fd1, buf, 1);



nread = read(fd1, buf1,1);
if(buf1[0] == 'q')
break;
}
close(fd1);
close(fd2);
return 0;
}