linux 串口多线程读写-红联Linux系统门户

我起了两个线程来操作串口：一个用于读数据，一个用于写数据。该程序用于两个arm9之间的串口全双工通信：即用一根串口线将两块板子连接起来。
问题是：我不知道该在哪里打开串口，若在主线程main中打开，则双方的读线程都收到乱码，同时也可以检测出写线程发出去的字符也有异常；若读写线程各自单独打开关闭串口，则写线程可以发出字符，但读线程始终无法读到数据。难道是我的线程有问题？
目前本人正处于非常苦恼之中，清各位大侠帮忙，贴出我的代码如下：
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include

#define NUM 20
int fd;

void writeThread(void* arg);
void readThread(void* arg);
/*
int openport(void)
{
// int fd;
struct termios options;
if((fd=open("/dev/tts/0",O_RDWR|O_NOCTTY|O_NONBLOCK|O_NDELAY))==-1)
{
perror("Can't open serial1 port.");
return -1;
}
/* tcgetattr(fd,&options);
cfsetispeed(&options,B9600);
cfsetospeed(&options,B9600);
options.c_cflag|=(CLOCAL|CREAD); //忽略控制信号线和使能读功能
options.c_cflag|=PARENB; //奇偶检验
options.c_cflag&=~PARODD; //偶校验
options.c_iflag |= (INPCK | ISTRIP);
options.c_cflag|=CSTOPB; //两个停止位
options.c_cflag&=~CSIZE;
options.c_cflag|=CS8; //8个数据位
options.c_lflag&=~(ICANON|ECHO|ISIG); //原始输入模式
options.c_oflag&=~OPOST; //原始输出

options.c_cc[VMIN]=0;
options.c_cc[VTIME]=0;
tcsetattr(fd,TCSANOW,&options);

printf("\nfd = %d\n",fd);
return fd;
}
*/

int
main(int argc, char* argv[])
{
int iret;
pthread_t id1, id2;

if((fd=open("/dev/tts/0",O_RDWR|O_NOCTTY|O_NONBLOCK|O_NDELAY))==-1)
{
perror("Can't open serial1 port.");
return -1;
}

iret = pthread_create(&id1, NULL, (void*)readThread, NULL);
if(iret != 0) {
printf("\nthread1_create is failed!\n");
}

iret = pthread_create(&id2, NULL, (void*)writeThread, NULL);
if(iret != 0) {
printf("\nthread1_create is failed!\n");
}

pthread_join(id1, NULL);
pthread_join(id2, NULL);

close(fd);
return 0;
}

void readThread(void* arg)
{
int nread, i;
int rcount = 0;
unsigned char buf[21];
while(1) {
sleep(1);
printf("\nnow it begain to read words.\n");
// printf("\nbefore reading, the words inf buf are %s\n",buf);
nread = read(fd, buf, 20);
if(nread == 20) {
printf("\nnread=%d", nread);
for(i = 0; i < 20; i++) {
printf("%c ", buf[1]);
}
rcount++;
printf("\nreceive packets: %d\n", rcount);
}
}
}

void writeThread(void* arg)
{
int i,j;
int fd;
unsigned char k = 'a';
int m;
int nwrite;
int scount = 0;
unsigned char serialTest[NUM] = {0};

for(m= 0;m {
serialTest[m] = k++;
}
/* open serial port */
while(1) {
sleep(1);
fd=open("/dev/tts/0",O_RDWR|O_NOCTTY|O_NONBLOCK|O_NDELAY);
nwrite = write(fd, serialTest, NUM);
write(fd, "\n", 1);
if(nwrite == 20) {
printf("\nwriteRadioFramewriteRadioFramewriteRadioFramewriteRadioFrame\n");
printf("\nnwrite = %d\n", nwrite);
for(j = 0; j< NUM; j++) {
printf("%c ",serialTest[j]);
}
scount++;
printf("\nsend packets: %d \n", scount++);
printf("\nwriteRadioFramewriteRadioFramewriteRadioFramewriteRadioFrame\n");
}
close(fd);
}
}

linux 串口多线程读写

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