串口不能发数据 收正常 达人帮忙看看程序
串口不能发数据 收正常 达人帮忙看看程序

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>
#include <termios.h>
#include <errno.h>


#define BAUDRATE B38400

#define MODEMDEVICE "/dev/ttyS0 "

#define _POSIX_SOURCE 1
#define FALSE 0

#define TRUE 1


volatile int STOP=FALSE;


main()

{

int fd,c, res;

struct termios oldtio,newtio;

char buf[255];


fd = open(MODEMDEVICE, O_RDWR | O_NOCTTY );

if (fd <0) {perror(MODEMDEVICE); exit(-1); }


tcgetattr(fd,&oldtio);


bzero(&newtio, sizeof(newtio));

newtio.c_cflag = BAUDRATE | CRTSCTS | CS8 | CLOCAL | CREAD;

newtio.c_iflag = IGNPAR;

newtio.c_oflag = 0;


newtio.c_lflag = 0;



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


tcflush(fd, TCIFLUSH);

tcsetattr(fd,TCSANOW,&newtio);


while (STOP==FALSE) {

write(fd, "abc ",3);


res = read(fd,buf,255);
if(res == 0) continue;

buf[res]=0;
printf( ":%s:%d\n ", buf, res);

if (buf[0]== 'z ') STOP=TRUE;

}

tcsetattr(fd,TCSANOW,&oldtio);

}



[解决办法]

newtio.c_cflag = BAUDRATE | CRTSCTS | CS8 | CLOCAL | CREAD;


newtio_new.c_cflag &= ~CSTOPB; //1 stop bits
newtio_new.c_cflag &= ~PARENB; //no parity check
[解决办法]
1,分别测试读和写.
2,检查你的串口线.
3,现不要设那么多项,仅仅用fsetispeed和fsetospeed设波特率看看.