serial.cpp

//
// Created by wxy on 7/16/17.
//
#include     <stdio.h>      /*标准输入输出定义*/
#include     <stdlib.h>     /*标准函数库定义*/
#include     <unistd.h>     /*Unix 标准函数定义*/
#include     <sys/types.h>
#include     <sys/stat.h>
#include     <fcntl.h>      /*文件控制定义*/
#include     <termios.h>    /*PPSIX 终端控制定义*/
#include     <errno.h>      /*错误号定义*/

int speed_arr[] = { B115200, B38400, B19200, B9600, B4800, B2400, B1200, B300,
                    B38400, B19200, B9600, B4800, B2400, B1200, B300, };
int name_arr[] = {115200,38400,  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) /*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;
    tcflush(fd,TCIFLUSH);
    options.c_cc[VTIME] = 150; /* 设置超时15 seconds*/
    options.c_cc[VMIN] = 0; /* Update the options and do it NOW */

    cfmakeraw(&options);
    if (tcsetattr(fd,TCSANOW,&options) != 0)
    {
        perror("SetupSerial 3");
        return (false);
    }
    return (true);
}