设置在linux下串口中断 [英] setting serial port interruption in linux

问题描述

我想设置为中断在Ubuntu串行端口（用C编写的程序），但它不工作。我已经检查串行通讯正常工作没有中断，所以我可能会设置一些错误。
在code是以下内容：

I am trying to set the interruption for a serial port in ubuntu (in program written in C), but it does not work. I have checked that the serial communication works correctly without the interruption, so I may be setting something wrong. The code is the following:

    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <unistd.h>
    #include <sys/types.h>
    #include <sys/socket.h>
    #include <netinet/in.h>
    #include <fcntl.h>
    #include <sys/signal.h>
    #include <errno.h>
    #include <termios.h>

    void signal_handler_IO (int status);   /* definition of signal handler */

    int n;
    int fd;
    int connected;
    struct termios termAttr;
    struct sigaction saio;

    int main(int argc, char *argv[])
    {
         fd = open("/dev/ttyUSB0", O_RDWR | O_NOCTTY | O_NDELAY);
         if (fd == -1)
         {
            perror("open_port: Unable to open /dev/ttyO1\n");
            exit(1);
         }

         saio.sa_handler = signal_handler_IO;
         saio.sa_flags = 0;
         saio.sa_restorer = NULL; 
         sigaction(SIGIO,&saio,NULL);

         fcntl(fd, F_SETFL, FNDELAY);
         fcntl(fd, F_SETOWN, getpid());

         tcgetattr(fd,&termAttr);
         baudRate = B115200; 
         cfsetispeed(&termAttr,B115200);
         cfsetospeed(&termAttr,B115200);
         termAttr.c_cflag &= ~PARENB;
         termAttr.c_cflag &= ~CSTOPB;
         termAttr.c_cflag &= ~CSIZE;
         termAttr.c_cflag |= CS8;
         termAttr.c_cflag |= (CLOCAL | CREAD);
         termAttr.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
         termAttr.c_iflag &= ~(IXON | IXOFF | IXANY);
         termAttr.c_oflag &= ~OPOST;
         tcsetattr(fd,TCSANOW,&termAttr);
         printf("UART1 configured....\n");

         connected = 1;
         while(connected == 1){
               // some code
         }

         close(fd);
         exit(0);             
    }

    void signal_handler_IO (int status)
    {
         printf("received data from UART.\n");
    }

所以随时时间的另一个设备通过配置的端口发送一条消息，该消息从UART接收到的数据。永远不会显示。

So anytime time another device send a message through the configured port, the message "received data from UART." is never displayed.

任何建议来解决这个问题？此外，如何系统涉及与串口中断？我看了一下signal.h中，但我还没有找到一个答案。我从这个页面中断理念：<一href=\"http://www.faqs.org/docs/Linux-HOWTO/Serial-Programming-HOWTO.html\">http://www.faqs.org/docs/Linux-HOWTO/Serial-Programming-HOWTO.html

Any suggestion to solve this problem? Also, how does the system relate the interruption with the serial port?, I have read about signal.h but I have not found an answer for that. I got the interruption idea from this page: http://www.faqs.org/docs/Linux-HOWTO/Serial-Programming-HOWTO.html

感谢您事先的任何帮助。
先谢谢了。

Thanks in advance for any help. Thanks in advance.

推荐答案

的问题是，你用<清除 FASYNC 标志禁止从文件描述符信号code> F_SETFL 。您需要设置，如果你想获得的信号：

The problem is that you're disabling signals from the file descriptor by clearing the FASYNC flag with F_SETFL. You need to set that if you want to get signals:

fcntl(fd, F_SETFL, FNDELAY|FASYNC);

此外，您可能想使用POSIX的名字，这些标志（ O_NDELAY 和 O_ASYNC ），而不是更多的可移植性BSD的名字，虽然二者将工作在Linux上。

Also, you might want to use the POSIX names for these flags (O_NDELAY and O_ASYNC) rather than the BSD names for more portability, though either will work on Linux.

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