嵌入式

linux串口编程经典源码

2019-07-13 03:26发布

站内文章 / 嵌入式Linux
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#include /*标准输入输出定义*/ #include /*标准函数库定义*/ #include /*Unix标准函数定义*/ #include /**/ #include /**/ #include /*文件控制定义*/ #include /*PPSIX终端控制定义*/ #include /*错误号定义*/ #ifndef FALSE #define FALSE (0) #endif #ifndef TRUE #define TRUE (!FALSE) #endif /***@brief 设置串口通信速率 *@param fd 类型 int 打开串口的文件句柄 *@param speed 类型 int 串口速度 *@return void*/ 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); } } /** *@brief 设置串口数据位，停止位和效验位 *@param fd 类型 int 打开的串口文件句柄* *@param databits 类型 int 数据位 取值 为 7 或者8* *@param stopbits 类型 int 停止位 取值为 1 或者2* *@param parity 类型 int 效验类型 取值为N,E,O,,S */ 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) /*设置数据位数*/ { case 7: options.c_cflag |= CS7; break; case 8: options.c_cflag |= CS8; break; default: fprintf(stderr,"Unsupported data size "); 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); /* 设置为奇效验*/ options.c_iflag |= INPCK; /* Disnable parity checking */ break; case 'e': case 'E': options.c_cflag |= PARENB; /* Enable parity */ options.c_cflag &= ~PARODD; /* 转换为偶效验*/ 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 "); return (FALSE); } /* 设置停止位*/ switch (stopbits) { case 1: options.c_cflag &= ~CSTOPB; break; case 2: options.c_cflag |= CSTOPB; break; default: fprintf(stderr,"Unsupported stop bits "); return (FALSE); } /* Set input parity option */ if (parity != 'n') options.c_iflag |= INPCK; options.c_cc[VTIME] = 150; // 15 seconds options.c_cc[VMIN] = 0; tcflush(fd,TCIFLUSH); /* Update the options and do it NOW */ if (tcsetattr(fd,TCSANOW,&options) != 0) { perror("SetupSerial 3"); return (FALSE); } return (TRUE); } /** *@breif 打开串口 */ int OpenDev(char *Dev) { int fd = open( Dev, O_RDWR ); //| O_NOCTTY | O_NDELAY if (-1 == fd) { /*设置数据位数*/ perror("Can't Open Serial Port"); return -1; } else return fd; } /** *@breif main() */ int main(int argc, char **argv) { int fd; int nread; char buff[512]; char *dev ="/dev/ttyS1"; fd = OpenDev(dev); if (fd>0) set_speed(fd,19200); else { printf("Can't Open Serial Port! "); exit(0); } if (set_Parity(fd,8,1,'N')== FALSE) { printf("Set Parity Error "); exit(1); } while(1) { while((nread = read(fd,buff,512))>0) { printf(" Len %d ",nread); buff[nread+1]='

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