Linux下串口程序开发

Linux串行口是计算机一种惯用的接口，含有连接线少，通讯简朴，得到广泛的RS-232-C接口(EIARS-232-C)1970年由美国电子工业协会(EIA)联合贝尔系统、调制解调器厂家及计算机终端生产厂家共同制(DTE)(DCE)255连4%50英尺。linux文献中，全部的设备文献普通都位于/dev下，其中串口一、串口二/dev/ttyS0/dev/ttyS1linuxreadwrite函数来完毕，#include#include<stdio.h>//#include#include<fcntl.h>//#include<unistd.h>linux原则函数定义#include<sys/ioctl.h>#include<termios.h> POSIX终端控制订义#include<sys/time.h>#includeintintchar*device=//设备途径，初始使用{//if(!strcmp(argv[t],"-d")&&(argc>{device=}}{printf("cannotuse/dev/tts/1\n");return-1;}fd=open(device,//不允许使用UART1，由于它已和PC//if(fd //{printf("opendeviceerror\n");return-1;}struct unsignedstruct unsignedshortunsignedshortunsignedshortunsignedshortunsignedcharunsignedchar/*输入模式标志/*输出模式标志/*控制模式标志/*localmodeflags/*linediscipline/*controlcharactersstructstructtermiosOpt;tcgetattr(fd,&Opt);////*@briefintspeedintintspeed_arr[]={B38400,B19200,B9600,B4800,B2400,B1200,B300,B38400,B19200,B9600,B4800,B2400,B1200,B300,};intname_arr[]={38400,19200,9600,4800,2400,1200,300,19200,9600,4800,2400,1200,300,voidset_speed(intfd,intspeed){ structtermios 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,status=tcsetattr(fd1,TCSANOW,&Opt);if(status!=0){perror("tcsetattrfd1");}}}}类型intdatabits类型intstopbits类型int取值为7或者取值为1或者parity类型intintset_Parity(intfd,intdatabits,intstopbits,int{structtermiosif(tcgetattrfd,&options)!=0){//perror("SetupSerial1");}options.c_cflag&=switch(databits/*设立数据位数{caseoptions.c_cflag|=CS7;caseoptions.c_cflag|=CS8;fprintf(stderr,"Unsupporteddatasize\n");return}switch(parity){case //caseoptions.c_cflag&=~PARENB; /*Clearparityenable*/casecaseoptions.c_cflag|(PARODD|PARENB)*设立为奇效验*/options.c_iflag|=INPCK;//INPCK:奇偶校验使能case'e':caseoptions.c_cflag|=PARENB; /*Enableparity*/options.c_cflag&=~PARODD; /*转换为偶效验*/options.c_iflag|=INPCK; /*Disnableparitychecking*/case Spacecase's':/*asnoparity*/options.c_cflag&=~PARENB;options.c_cflag&=~CSTOPB;options.c_iflag|=INPCK;fprintf(stderr,"Unsupportedfprintf(stderr,"Unsupportedparity\n");return(FALSE);}//switch{caseoptions.c_cflag&=~CSTOPB;//1个停止位caseoptions.c_cflag|=CSTOPB;//2个停止位fprintf(stderr,"Unsupportedstopbits\n");return(FALSE);}////options.c_cc[VTIME]=150;/*设立超时15seconds*/options.c_cc[VMIN]0*UpdatetheoptionsanddoitNOW*///if(tcsetattr(fd,TCSANOW,&options)!={perror("SetupSerial3");return(FALSE);}return}newtio.c_lflag&=~(ICANONnewtio.c_lflag&=~(ICANON|ECHO|ECHOE|ISIG);//newtio.c_oflag&~(OPOST);//voidvoidinit_ttyS(int{structtermiosbzero(&newtio,//tcgetattr(fd,//将输入波特率设为//将输出波特率设为19200cfsetispeed(&newtio,B19200);cfsetospeed(&newtio,//newtio.c_cflag|=(CLOCAL|//无校验8位数据位1位停止位newtio.c_cflag&~PARENB;newtio.c_cflag&~CSTOPB;newtio.c_cflag&=~CSIZE;8newtio.c_cflag|=//newtio.c_lflag&=~(ICANON|ECHO|ECHOE|ISIG);newtio.c_oflag&=~(OPOST);// = =//tcflush(fd,//}charbuff[1024]; intreadBytecharbuff[1024]; intreadByte=void{//read(fd,void{//read(fd,RXBUF,#ifintret,n,pos,retval;fd_setrfds;structtimevaltvpos0;//for(n=0;n<RX_len;{RXBUF[n]=}FD_ZERO(&rfds);//清空串口接受端口集FD_SET(fd,&rfds)设立串口接受端口集tv.tv_sec=2;tv.tv_usec=while(FD_ISSET(fd,&rfds)){//每次循环都要清空，否则不会检测到有变化FD_ZERO(&rfds);//清空串口接受端口集FD_SET(fd,&rfds);//retval=select(fd+1,&rfds,NULL,NULL,&tv);if(retval==-1){}else{//retret=read(fd,RXBUF,RX_len);pos+=ret;//printf("ret=%dif((RXBUF[pos-2]'\r'&RXBUF[pos-1]'\n'){retval=select(fd+1,&rfds,NULL,NULL,&tv);if(!retval)//nodatas{}}}{}}}com口堵塞，程序就死了。Select的函数格式(我所说的是Unix系统下的伯克利socketintselect(intintselect(intmaxfdp,fd_set*readfds,fd_set*writefds,fd_set*errorfds,structstruct能够理解为一种集合，这个集合中寄存的是文献描述符(filedescriptor)，即socket句柄就是一种文献描述符。fd_set集合能够通过某些宏由人为来操作，例FD_ZERO(fd_set*set):FD_SET(intfd,fd_set*set):FD_CLR(intfd,fd_set*set):FD_ISSET(intfd,fd_set*set):检查集合中指定的文献描述符与否能够structstructstructlongtv_sec;longtv_unsec;}selectint1Windows中这个参数的值无所谓，能够设立不对的。fd_setfd_set构造的指针，这个集合中应当涉及文献描述符，我们是要监如果这个集合中有一种文献可读，select0的值，表达有timeout参数再判断与否超时，若超出timeout的时间，select0NULL值，表达fd_setfd_set构造的指针，这个集合中应当涉及文献描述符，我们是要监如果这个集合中有一种文献可写，select0的值，表达有timeout参数再判断与否超时，若超出timeout的时间，select0NULL值，表达fd_setstructtimeval*selectselect处在三种状态，NULLselect置于阻塞状态，000，有变化返回一种正值；第三，timeout0selecttimeout时间内阻塞，超时负值：select错误正值：某些文献可读写或出错0：等待超时，没有可读selectselectFD_ZEROFD_SET来初始selectFD_ISSET测试描述符集，FD_CLR来去除描述符集。charbuffer[1024];charbuffer[1024]; nByte=write(fd,buffer#include<stdio.h>#include<string.h>#include<stdlib.h>#include<fcntl.h>#include<unistd.h>#include<sys/ioctl.h>#include<stdio.h>#include<string.h>#include<stdlib.h>#include<fcntl.h>#include<unistd.h>#include<sys/ioctl.h>#include<termios.h>#include<sys/select.h>#include//#include#defineACK_SUCCESS#defineACK_FAIL#defineACK_FULL#define //#defineACK_USER_EXIST////////#define#define//externunsignedcharTXBUF[9900];externunsignedcharRXBUF[9900];externunsignedcharrev_ok;externunsignedintTX_len;externunsignedintexternunsignedcharone_onecontrast(unsignedcharuser_number_h,unsignedcharexternunsignedcharone_morecontrast(void);externunsignedcharGet_UserNumber_Right(void);externunsignedcharset_addmode(unsignedcharexternunsignedcharadd_Fingerprint(unsignedchartime_number,unsignedcharunsignedcharuser_number_l,unsignedexternunsignedcharexternunsignedchardel_oneuser(unsignedcharuser_number_h,unsignedcharexternunsignedcharintunsignedcharUSER_NUMBER_H;//顾客号高8位unsignedcharUSER_NUMBER_L;//顾客号低8位unsignedcharUSER_RIGHT; //顾客权限unsignedchar //unsignedchar //unsignedcharCharToHex(unsignedcharch);unsignedcharselect_one_onecontrast(void);voidselect_Get_Usernumber_right(void); intSERIAL_TX(void){intretwrite(fdTXBUF, //if(ret //{ printf("Writedeviceerror!\n");return-1; ret=}return} voidSERIAL_RX(void){//read(fd,RXBUF,#ifintret,n,pos,retval;fd_setrfds;structtimevaltvpos0;//指向接受缓冲tv.tv_sec=2;tv.tv_usec=for(n=0;n<RX_len;{RXBUF[n]=} //while(1)//{FD_ZERO(&rfds);//清空串口接受端口集FD_SET(fd,&rfds);//设立串口接受端口集retvalselect(fd+1,&rfds,NULL,NULL,&tv);if(retval==-1){}else{//ret=read(fd,RXBUF,RX_len);pos+=ret;//printf("ret=%dif((RXBUF[pos-2]=='\r')&(RXBUF[pos-1]=='\n')) 确实{retval=select(fd+1,&rfds,NULL,NULL,&tv);if(!retval)//nodatas{}}{

}}}}voidinit_ttyS(int{structtermiosbzero(&newtio,tcgetattr(fd //cfsetispeed(&newtio //将输入波特率设为cfsetospeed(&newtio,B19200); //将输出波特率设为19200newtio.c_cflag|=(CLOCAL|CREAD); //使能接受并使能本地状态