Linux系统串口接收数据编
http://blog.csdn.net/bg2bkk/article/details/8668576
之前基于IBM deveplopworks社区的代码,做了串口初始化和发送的程序,今天在此基础上添加了读取串口数据的程序。首先是最简单的循环读取程序,第二个是通过软中断方式,使用信号signal机制读取串口,这里需要注意的是硬件中断是设备驱动层级的,而读写串口是用户级行为,只能通过信号机制模拟中断,信号机制的发生和处理其实于硬件中断无异,第三个是通过select系统调用,在没有数据时阻塞进程,串口有数据需要读时唤醒进程。第二个和第三个例子都能用来后台读取数据,值得学习。
代码一:循环读取数据
- #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 FALSE -1
- #define TRUE 0
- int speed_arr[] = { B38400, B19200, B9600, B4800, B2400, B1200, B300,B38400, B19200, B9600, B4800, B2400, B1200, B300, };
- int name_arr[] = {38400, 19200, 9600, 4800, 2400, 1200, 300, 38400, 19200, 9600, 4800, 2400, 1200, 300, };
- void set_speed(int fd, int speed){
- int i;
- int status;
- struct termios Opt;
- tcgetattr(fd, &Opt);
- for ( i= 0; i < sizeof(speed_arr) / sizeof(int); i++) {
- if (speed == name_arr[i]) {
- tcflush(fd, TCIOFLUSH);
- cfsetispeed(&Opt, speed_arr[i]);
- cfsetospeed(&Opt, speed_arr[i]);
- status = tcsetattr(fd, TCSANOW, &Opt);
- if (status != 0) {
- perror("tcsetattr fd1");
- return;
- }
- tcflush(fd,TCIOFLUSH);
- }
- }
- }
- int set_Parity(int fd,int databits,int stopbits,int parity)
- {
- struct termios options;
- if ( tcgetattr( fd,&options) != 0) {
- perror("SetupSerial 1");
- return(FALSE);
- }
- options.c_cflag &= ~CSIZE;
- switch (databits)
- {
- case 7:
- options.c_cflag |= CS7;
- break;
- case 8:
- options.c_cflag |= CS8;
- break;
- default:
- fprintf(stderr,"Unsupported data size\n"); return (FALSE);
- }
- switch (parity)
- {
- case 'n':
- case 'N':
- options.c_cflag &= ~PARENB; /* Clear parity enable */
- options.c_iflag &= ~INPCK; /* Enable parity checking */
- break;
- case 'o':
- case 'O':
- options.c_cflag |= (PARODD | PARENB);
- options.c_iflag |= INPCK; /* Disnable parity checking */
- break;
- case 'e':
- case 'E':
- options.c_cflag |= PARENB; /* Enable parity */
- options.c_cflag &= ~PARODD;
- options.c_iflag |= INPCK; /* Disnable parity checking */
- break;
- case 'S':
- case 's': /*as no parity*/
- options.c_cflag &= ~PARENB;
- options.c_cflag &= ~CSTOPB;break;
- default:
- fprintf(stderr,"Unsupported parity\n");
- return (FALSE);
- }
- switch (stopbits)
- {
- case 1:
- options.c_cflag &= ~CSTOPB;
- break;
- case 2:
- options.c_cflag |= CSTOPB;
- break;
- default:
- fprintf(stderr,"Unsupported stop bits\n");
- return (FALSE);
- }
- /* Set input parity option */
- if (parity != 'n')
- options.c_iflag |= INPCK;
- tcflush(fd,TCIFLUSH);
- options.c_cc[VTIME] = 150;
- options.c_cc[VMIN] = 0; /* Update the options and do it NOW */
- if (tcsetattr(fd,TCSANOW,&options) != 0)
- {
- perror("SetupSerial 3");
- return (FALSE);
- }
- return (TRUE);
- }
- int main()
- {
- printf("This program updates last time at %s %s\n",__TIME__,__DATE__);
- printf("STDIO COM1\n");
- int fd;
- fd = open("/dev/ttyS0",O_RDWR);
- if(fd == -1)
- {
- perror("serialport error\n");
- }
- else
- {
- printf("open ");
- printf("%s",ttyname(fd));
- printf(" succesfully\n");
- }
- set_speed(fd,115200);
- if (set_Parity(fd,8,1,'N') == FALSE) {
- printf("Set Parity Error\n");
- exit (0);
- }
- char buf[] = "fe55aa07bc010203040506073d";
- write(fd,&buf,26);
- char buff[512];
- int nread;
- while(1)
- {
- if((nread = read(fd, buff, 512))>0)
- {
- printf("\nLen: %d\n",nread);
- buff[nread+1] = '\0';
- printf("%s",buff);
- }
- }
- close(fd);
- return 0;
- }
代码清单二:通过signal机制读取数据
- #include<stdio.h>
- #include<stdlib.h>
- #include<unistd.h>
- #include<sys/types.h>
- #include<sys/stat.h>
- #include<sys/signal.h>
- #include<fcntl.h>
- #include<termios.h>
- #include<errno.h>
- #define FALSE -1
- #define TRUE 0
- #define flag 1
- #define noflag 0
- int wait_flag = noflag;
- int STOP = 0;
- int res;
- int speed_arr[] =
- { B38400, B19200, B9600, B4800, B2400, B1200, B300, B38400, B19200, B9600,
- B4800, B2400, B1200, B300, };
- int name_arr[] =
- { 38400, 19200, 9600, 4800, 2400, 1200, 300, 38400, 19200, 9600, 4800, 2400,
- 1200, 300, };
- void
- set_speed (int fd, int speed)
- {
- int i;
- int status;
- struct termios Opt;
- tcgetattr (fd, &Opt);
- for (i = 0; i < sizeof (speed_arr) / sizeof (int); i++)
- {
- if (speed == name_arr[i])
- {
- tcflush (fd, TCIOFLUSH);
- cfsetispeed (&Opt, speed_arr[i]);
- cfsetospeed (&Opt, speed_arr[i]);
- status = tcsetattr (fd, TCSANOW, &Opt);
- if (status != 0)
- {
- perror ("tcsetattr fd1");
- return;
- }
- tcflush (fd, TCIOFLUSH);
- }
- }
- }
- int
- set_Parity (int fd, int databits, int stopbits, int parity)
- {
- struct termios options;
- if (tcgetattr (fd, &options) != 0)
- {
- perror ("SetupSerial 1");
- return (FALSE);
- }
- options.c_cflag &= ~CSIZE;
- switch (databits)
- {
- case 7:
- options.c_cflag |= CS7;
- break;
- case 8:
- options.c_cflag |= CS8;
- break;
- default:
- fprintf (stderr, "Unsupported data size\n");
- return (FALSE);
- }
- switch (parity)
- {
- case 'n':
- case 'N':
- options.c_cflag &= ~PARENB; /* Clear parity enable */
- options.c_iflag &= ~INPCK; /* Enable parity checking */
- break;
- case 'o':
- case 'O':
- options.c_cflag |= (PARODD | PARENB);
- options.c_iflag |= INPCK; /* Disnable parity checking */
- break;
- case 'e':
- case 'E':
- options.c_cflag |= PARENB; /* Enable parity */
- options.c_cflag &= ~PARODD;
- options.c_iflag |= INPCK; /* Disnable parity checking */
- break;
- case 'S':
- case 's': /*as no parity */
- options.c_cflag &= ~PARENB;
- options.c_cflag &= ~CSTOPB;
- break;
- default:
- fprintf (stderr, "Unsupported parity\n");
- return (FALSE);
- }
- switch (stopbits)
- {
- case 1:
- options.c_cflag &= ~CSTOPB;
- break;
- case 2:
- options.c_cflag |= CSTOPB;
- break;
- default:
- fprintf (stderr, "Unsupported stop bits\n");
- return (FALSE);
- }
- /* Set input parity option */
- if (parity != 'n')
- options.c_iflag |= INPCK;
- tcflush (fd, TCIFLUSH);
- options.c_cc[VTIME] = 150;
- options.c_cc[VMIN] = 0; /* Update the options and do it NOW */
- if (tcsetattr (fd, TCSANOW, &options) != 0)
- {
- perror ("SetupSerial 3");
- return (FALSE);
- }
- return (TRUE);
- }
- void
- signal_handler_IO (int status)
- {
- printf ("received SIGIO signale.\n");
- wait_flag = noflag;
- }
- int
- main ()
- {
- printf ("This program updates last time at %s %s\n", __TIME__, __DATE__);
- printf ("STDIO COM1\n");
- int fd;
- struct sigaction saio;
- fd = open ("/dev/ttyUSB0", O_RDWR);
- if (fd == -1)
- {
- perror ("serialport error\n");
- }
- else
- {
- printf ("open ");
- printf ("%s", ttyname (fd));
- printf (" succesfully\n");
- }
- saio.sa_handler = signal_handler_IO;
- sigemptyset (&saio.sa_mask);
- saio.sa_flags = 0;
- saio.sa_restorer = NULL;
- sigaction (SIGIO, &saio, NULL);
- //allow the process to receive SIGIO
- fcntl (fd, F_SETOWN, getpid ());
- //make the file descriptor asynchronous
- fcntl (fd, F_SETFL, FASYNC);
- set_speed (fd, 115200);
- if (set_Parity (fd, 8, 1, 'N') == FALSE)
- {
- printf ("Set Parity Error\n");
- exit (0);
- }
- char buf[255];
- while (STOP == 0)
- {
- usleep (100000);
- /* after receving SIGIO ,wait_flag = FALSE,input is availabe and can be read */
- if (wait_flag == 0)
- {
- memset (buf, 0, sizeof(buf));
- res = read (fd, buf, 255);
- printf ("nread=%d,%s\n", res, buf);
- // if (res ==1)
- // STOP = 1; /*stop loop if only a CR was input */
- wait_flag = flag; /*wait for new input */
- }
- }
- close (fd);
- return 0;
- }
代码三:通过select系统调用进行io多路切换,实现异步读取串口数据
- #include<stdio.h>
- #include<stdlib.h>
- #include<unistd.h>
- #include<sys/types.h>
- #include<sys/stat.h>
- #include<sys/signal.h>
- #include<fcntl.h>
- #include<termios.h>
- #include<errno.h>
- #define FALSE -1
- #define TRUE 0
- #define flag 1
- #define noflag 0
- int wait_flag = noflag;
- int STOP = 0;
- int res;
- int speed_arr[] =
- { B38400, B19200, B9600, B4800, B2400, B1200, B300, B38400, B19200, B9600,
- B4800, B2400, B1200, B300, };
- int name_arr[] =
- { 38400, 19200, 9600, 4800, 2400, 1200, 300, 38400, 19200, 9600, 4800, 2400,
- 1200, 300, };
- void
- set_speed (int fd, int speed)
- {
- int i;
- int status;
- struct termios Opt;
- tcgetattr (fd, &Opt);
- for (i = 0; i < sizeof (speed_arr) / sizeof (int); i++)
- {
- if (speed == name_arr[i])
- {
- tcflush (fd, TCIOFLUSH);
- cfsetispeed (&Opt, speed_arr[i]);
- cfsetospeed (&Opt, speed_arr[i]);
- status = tcsetattr (fd, TCSANOW, &Opt);
- if (status != 0)
- {
- perror ("tcsetattr fd1");
- return;
- }
- tcflush (fd, TCIOFLUSH);
- }
- }
- }
- int
- set_Parity (int fd, int databits, int stopbits, int parity)
- {
- struct termios options;
- if (tcgetattr (fd, &options) != 0)
- {
- perror ("SetupSerial 1");
- return (FALSE);
- }
- options.c_cflag &= ~CSIZE;
- switch (databits)
- {
- case 7:
- options.c_cflag |= CS7;
- break;
- case 8:
- options.c_cflag |= CS8;
- break;
- default:
- fprintf (stderr, "Unsupported data size\n");
- return (FALSE);
- }
- switch (parity)
- {
- case 'n':
- case 'N':
- options.c_cflag &= ~PARENB; /* Clear parity enable */
- options.c_iflag &= ~INPCK; /* Enable parity checking */
- break;
- case 'o':
- case 'O':
- options.c_cflag |= (PARODD | PARENB);
- options.c_iflag |= INPCK; /* Disnable parity checking */
- break;
- case 'e':
- case 'E':
- options.c_cflag |= PARENB; /* Enable parity */
- options.c_cflag &= ~PARODD;
- options.c_iflag |= INPCK; /* Disnable parity checking */
- break;
- case 'S':
- case 's': /*as no parity */
- options.c_cflag &= ~PARENB;
- options.c_cflag &= ~CSTOPB;
- break;
- default:
- fprintf (stderr, "Unsupported parity\n");
- return (FALSE);
- }
- switch (stopbits)
- {
- case 1:
- options.c_cflag &= ~CSTOPB;
- break;
- case 2:
- options.c_cflag |= CSTOPB;
- break;
- default:
- fprintf (stderr, "Unsupported stop bits\n");
- return (FALSE);
- }
- /* Set input parity option */
- if (parity != 'n')
- options.c_iflag |= INPCK;
- tcflush (fd, TCIFLUSH);
- options.c_cc[VTIME] = 150;
- options.c_cc[VMIN] = 0; /* Update the options and do it NOW */
- if (tcsetattr (fd, TCSANOW, &options) != 0)
- {
- perror ("SetupSerial 3");
- return (FALSE);
- }
- return (TRUE);
- }
- void
- signal_handler_IO (int status)
- {
- printf ("received SIGIO signale.\n");
- wait_flag = noflag;
- }
- int
- main ()
- {
- printf ("This program updates last time at %s %s\n", __TIME__, __DATE__);
- printf ("STDIO COM1\n");
- int fd;
- fd = open ("/dev/ttyUSB0", O_RDWR);
- if (fd == -1)
- {
- perror ("serialport error\n");
- }
- else
- {
- printf ("open ");
- printf ("%s", ttyname (fd));
- printf (" succesfully\n");
- }
- set_speed (fd, 115200);
- if (set_Parity (fd, 8, 1, 'N') == FALSE)
- {
- printf ("Set Parity Error\n");
- exit (0);
- }
- char buf[255];
- fd_set rd;
- int nread = 0;
- while(1)
- {
- FD_ZERO(&rd);
- FD_SET(fd, &rd);
- while(FD_ISSET(fd, &rd))
- {
- if(select(fd+1, &rd, NULL,NULL,NULL) < 0)
- {
- perror("select error\n");
- }
- else
- {
- while((nread = read(fd, buf, sizeof(buf))) > 0)
- {
- printf("nread = %d,%s\n",nread, buf);
- printf("test\n");
- memset(buf, 0 , sizeof(buf));
- }
- }
- }
- }
- close (fd);
- return 0;
- }
Linux系统串口接收数据编的更多相关文章
- rsync Linux系统下的数据镜像备份工具
rsync是Linux系统下的数据镜像备份工具,从软件的命名上就可以看出来了——remote sync.rsync支持大多数的类Unix系统,无论是Linux.Solaris还是BSD上都经过了良好的 ...
- Django项目:CMDB(服务器硬件资产自动采集系统)--07--06CMDB测试Linux系统采集硬件数据的命令02
#settings.py """ Django settings for AutoCmdb project. Generated by 'django-admin sta ...
- Django项目:CMDB(服务器硬件资产自动采集系统)--06--06CMDB测试Linux系统采集硬件数据的命令01
#base.py # ————————01CMDB获取服务器基本信息———————— from config import settings #配置文件 class BasePlugin(object ...
- C# 串口接收数据中serialPort.close()死锁
最近在做一个有关高铁模拟仓显示系统的客户端程序,在这个程序中要运用串口serialPort传输数据,因为每次接收数据结束后要更新UI界面,所以就用到了的Invoke,将更新UI的程序代码封装到一个方法 ...
- linux系统串口编程实例
在嵌入式开发中一些设备如WiFi.蓝牙......都会通过串口进行主机与从机间通信,串口一般以每次1bit位进行传输,效率相对慢. 在linux系统下串口的编程有如下几个步骤,最主要的是串口初始化! ...
- STM32 ucosii 串口接收数据 遇到的问题及解决思路
写一个程序,用到了ucos ii ,串口在中断中接收数据(一包数据 8个字节 包含: 1byte包头 5byte数据 1byte校验和 1byte 包尾 ) ,数据由上位机每隔500ms发送一次,在串 ...
- Linux 系统串口信息查看
先确认系统启动的时候串口的信息. ECM_5412@chenfl:~$ dmesg | grep tty [ 0.000000] console [tty0] enabled [ 2.511678] ...
- C# 解决串口接收数据不完整
方法1: 使 用缓存机制完成.首先通过定义一个成员变量List<byte> buffer = new List<byte> (4096);用来存放所有的数据,在接收函数里,通过 ...
- linux内核网络接收数据流程图【转】
转自:http://blog.chinaunix.net/uid-23069658-id-3141409.html 4.3 数据接收流程图 各层主要函数以及位置功能说明: 1)s ...
随机推荐
- IAR for MSP430 关于添加自定义头文件的两种方法【转】
前言:第一次接触这个软件,编译一个例程一直出现没有包含头文件的错误,在网上找了好几个方法都没什么效果,看到了篇文章,利用里面的方法1解决了,特此复制下来保存学习用. 原文链接:https://blog ...
- 【codeforces 807B】T-Shirt Hunt
[题目链接]:http://codeforces.com/contest/807/problem/B [题意] 你在另外一场已经结束的比赛中有一个排名p; 然后你现在在进行另外一场比赛 然后你当前有一 ...
- PHP学习总结(2)——PHP入门篇之PHP代码标识
认识PHP代码标识 想在页面中编写PHP代码非常容易,如下面代码: <?php echo "想学习php吗?来慕课网吧";?> 就像你可以编写JavaScript脚本 ...
- redis 在 Linux 和 Windows 上的安装配置
最近需要在服务器上安装 redis,虽然只是一个小事情,但这个过程中也遇到了不少的问题,所以做一个总结,也希望能给到其他人一些帮助. 本文记录了 linux 系统和 windows 系统的 redis ...
- 基于【SpringBoot】的微服务【Jenkins】自动化部署
最近,也是抽空整理了一些在工作中积累的经验,通过博客记录下来分享给大家,希望能对大家有所帮助: 一.关于自动化部署 关于自动化部署的优点,我就不在这里赘述了:只要想想手工打包.上传.部署.重启的种种, ...
- Unknown tag (s:property).
Unknown tag (s:property). 在jsp文件中加入此句话:<%@ taglib uri="/struts-tags" prefix="s&quo ...
- pl/sql sql窗口允许输出和允许变量替换
pl/sql sql窗口允许输出和允许变量替换 允许输出:类似在命令窗口中输入的 setserveroutput on; 允许变量替换:如果点击了这个,类似于执行 set define off命令 在 ...
- [ES6] Proxy & Reflect
Proxy and Reflect API works nicely together. About how to use Proxy, check this post. Let's see abou ...
- js面向对象编程: js类定义函数时prototype和this差别?
在面向对象编写js脚本时,定义实例方法主要有两种 例如以下: function ListCommon2(afirst) { var first=afirst; this.do1=function () ...
- 【机房重构】—上机&订餐
前几天通过UML图中的时序图.让我对于机房重构中的每一条线理解的更加清晰.曾经认为上机特别的乱,在一次偶遇中,得知了原来它能够转化成我们平时订餐.以下就听我说一说上机&订餐的故事吧! 又是发生 ...