#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>      #include      <string.h>#define TRUE 0  #define FALSE -1  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\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);  /* 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\n");            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\n");            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; }int OpenPort(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;    }}int main(int argc, char **argv){            int fd;    int nread;    char buff[512];    char *dev = "/dev/ttyAMA0";        fd = OpenPort(dev);        if(fd>0){        set_speed(fd,9600);    }else{        printf("Can‘t Open Serial Port!\n");        exit(0);    }      if(set_Parity(fd,8,1,‘N‘)== FALSE){        printf("Set Parity Error\n");        exit(1);    }      while(1){           while((nread = read(fd,buff,512))>0){                      printf("\n长度:%d\n",nread);              buff[nread+1]=‘\0‘;            printf("\n内容为:%s\n",buff);            memset(buff,0,512);                    }      }    close(fd);    exit(0);}