LINUX 串口通讯源码.doc

主要函数int openport(char *Dev) /打开串口int setport(int fd, int baud,int databits,int stopbits,int parity)/设置串口，波特率，数据位，停止位，校验int readport(int fd,char *buf,int len,int maxwaittime)/读数据，参数为串口，BUF，长度，超时时间int writeport(int fd,char *buf,int len)/发送数据void clearport(int fd)/如果出现数据与规约不符合，可以调用这个函数来刷新串口读写数据如果有BUG，请大家及时回复给我,EMAIL:41063473QQ.COM。#include #include #include #include #include #include #include int openport(char *Dev)intfd = open( Dev, O_RDWR|O_NOCTTY|O_NDELAY );if (-1 = fd) perror(Cant Open Serial Port);return -1;elsereturn fd;int setport(int fd, int baud,int databits,int stopbits,int parity)int baudrate;struct termios newtio;switch(baud)case 300:baudrate=B300;break;case 600:baudrate=B600;break;case 1200:baudrate=B1200;break;case 2400:baudrate=B2400;break;case 4800:baudrate=B4800;break;case 9600:baudrate=B9600;break;case 19200:baudrate=B19200;break;case 38400:baudrate=B38400;break;default :baudrate=B9600;break;tcgetattr(fd,&newtio);bzero(&newtio,sizeof(newtio); /setting c_cflagnewtio.c_cflag &=CSIZE;switch (databits) /*设置数据位数*/case 7:newtio.c_cflag |= CS7; /7位数据位break;case 8:newtio.c_cflag |= CS8; /8位数据位break;default:newtio.c_cflag |= CS8;break; switch (parity) /设置校验case n:case N:newtio.c_cflag &= PARENB; /* Clear parity enable */newtio.c_iflag &= INPCK; /* Enable parity checking */break;case o:case O:newtio.c_cflag |= (PARODD | PARENB); /* 设置为奇效验*/newtio.c_iflag |= INPCK; /* Disnable parity checking */break;case e:case E:newtio.c_cflag |= PARENB; /* Enable parity */newtio.c_cflag &= PARODD; /* 转换为偶效验*/newtio.c_iflag |= INPCK; /* Disnable parity checking */break;case S:case s: /*as no parity*/ newtio.c_cflag &= PARENB;newtio.c_cflag &= CSTOPB;break;default:newtio.c_cflag &= PARENB; /* Clear parity enable */newtio.c_iflag &= INPCK; /* Enable parity checking */break; switch (stopbits)/设置停止位case 1:newtio.c_cflag &= CSTOPB; /1break;case 2:newtio.c_cflag |= CSTOPB; /2 break;default:newtio.c_cflag &= CSTOPB;break;newtio.c_ccVTIME = 0;newtio.c_ccVMIN = 0;newtio.c_cflag |= (CLOCAL|CREAD);newtio.c_oflag|=OPOST;newtio.c_iflag &=(IXON|IXOFF|IXANY); cfsetispeed(&newtio,baudrate); cfsetospeed(&newtio,baudrate); tcflush(fd, TCIFLUSH);if (tcsetattr(fd,TCSANOW,&newtio) != 0)perror(SetupSerial 3);return -1;return 0;int readport(int fd,char *buf,int len,int maxwaittime)/读数据，参数为串口，BUF，长度，超时时间int no=0;int rc;int rcnum=len;struct timeval tv;fd_set readfd;tv.tv_sec=maxwaittime/1000;/SECONDtv.tv_usec=maxwaittime%1000*1000;/USECONDFD_ZERO(&readfd);FD_SET(fd,&readfd);rc=select(fd+1,&readfd,NULL,NULL,&tv);if(rc0)while(len)rc=read(fd,&bufno,1);if(rc0)no=no+1;len=len-1;if(no!=rcnum)return -1;/如果收到的长度与期望长度不一样，返回-1return rcnum;/收到长度与期望长度一样，返回长度elsereturn -1;return -1;int writeport(int fd,char *buf,int len)/发送数据write(fd,buf,len);void clearport(int fd)/如果出现数据与规约不符合，可以调用这个函数来刷新串口读写数据tcflush(fd,TCIOFLUSH);main()int fd,rc,i,ret;unsigned char rbuf256;unsigned char wbuf256=;for(i=0;i0)ret=setport(fd,4800,8,1,o