c 串口读写数据实例解析

一 前记

   程序员就是不断地砌砖头，然后用砖头，把砖头模块化，用的时候直接调用，能够节省很多精力。

二 实例：

  

#include <stdio.h>
#include <unistd.h>                     //Used for UART
#include <fcntl.h>                      //Used for UART
#include <termios.h>                    //Used for UART

typedef unsigned char uint8;

void dump8(uint8 *buf, int len)
{
        for(int icnt = 0; icnt < len; icnt++)
        {
                printf("0x%x,",buf[icnt]);
        }

        printf("
	");
}


int main(void)
{
        int data_num = 0;

        printf("
UART test

");

        int uart0_filestream = -1;

        uart0_filestream = open("/dev/ttyUSB3", O_RDONLY | O_NOCTTY | O_NDELAY);                //Open in non blocking read/write mode
        if (uart0_filestream == -1)
        {
                printf("Error - Unable to open UART.  Ensure it is not in use by another application
");
                return -1;
        }


        struct termios options;
        tcgetattr(uart0_filestream, &options);
        options.c_cflag = B921600 | CS8 | CLOCAL | CREAD;         //<Set baud rate
        options.c_iflag = IGNPAR;
        options.c_oflag = 0;
        options.c_lflag = 0;
        tcflush(uart0_filestream, TCIFLUSH);
        tcsetattr(uart0_filestream, TCSANOW, &options);

        printf("init complete, listening...

");


        while(1)
        {

        if (uart0_filestream != -1)
        {
                unsigned char buf1[2];
                int n = read(uart0_filestream, buf1, 2);
                if ((n > 0) && (buf1[0] == 0xff) &&(buf1[1] == 0xff))
                {
                        unsigned char buf2[2];
                        dump8(buf1,2);
                        n = read(uart0_filestream, buf2, 2);
                        dump8(buf2,2);
                        if (n > 0 && (buf2[0] == 0x40) &&(buf2[1] == 0x01))
                        {

                                unsigned char buf3[640];

                                data_num = read(uart0_filestream, buf3, 640);

                                if(data_num > 0)
                                {

                                        dump8(buf3,data_num);
                                }

                        }
                }

        }

        }

三 总结：

   运行一下，就知道结果了。