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发表于 2019-5-30 11:22:39
8423 浏览 3 回复
linux下读取串口数据
2阿木币
我根据网上教程，编写test.c代码，然后gcc -o test test.c编译，然后./test运行，可是这样好像并不能直接读取串口数据，我还得另外再用cutecom(linux下的串口调试助手)打开该串口，这边终端才不断有数据读出，可是这样一来数据就变得有些乱了，但是cutecom里显示的数据又是正常的，这让我疑惑很久，不知道是哪里出现问题，接下来放下代码和运行效果图：
#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<math.h>
#include<string.h>
#define FALSE -1
#define TRUE 0
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) {
tcflush(fd, TCIOFLUSH);
cfsetispeed(&Opt, speed_arr);
cfsetospeed(&Opt, speed_arr);
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)
{
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);
options.c_iflag |= INPCK; /* Disnable parity checking */
break;
case 'e':
case 'E':
options.c_cflag |= PARENB; /* Enable parity */
options.c_cflag &= ~PARODD;
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);
}
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;
options.c_cc[VMIN] = 0; /* Update the options and do it NOW */
if (tcsetattr(fd,TCSANOW,&options) != 0)
{
perror("SetupSerial 3");
return (FALSE);
}
return (TRUE);
}
int main()
{
printf("This program updates last time at %s %s\n",__TIME__,__DATE__);
printf("STDIO COM1\n");
int fd;
fd = open("/dev/ttyUSB0",O_RDWR);
if(fd == -1)
{
perror("serialport error\n");
}
else
{
printf("open ");
printf("%s",ttyname(fd));
printf(" succesfully\n");
}
set_speed(fd,115200);
set_Parity(fd,8,1,'N');
if (set_Parity(fd,8,1,'N') == FALSE) {
printf("Set Parity Error\n");
exit (0);
} else{
printf("hahahahha!\n");
}
int buff[48];
int nread;
//char data = '0';
//int dread;
while(1)
{
printf("get in!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!\n");
nread=read(fd,buff,48);
//dread=read(fd,&data,1);
//printf("Len: %d\n",dread);
printf("Len: %d\n",nread);
int i=0 ;
while(i<48){
printf("%d ",buff);
i++;
}
//printf("%c\n",data);
//printf("%c\n",CharToHex(data));
printf("\nget out~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n");
usleep(100000);
}
close(fd);
return 0;
}
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最佳答案
查看完整内容
1、nread=read(fd,buff,48)，打印的消息里面Len:0，也就是没有读取到数据，建议确认一下你的数据是否写入对应的串口设备中。
2、你的打印中
buff对应的应该是首地址，你这样的循环打印，意义不大
3、验证的时候将双侧显示的数据格式保持一致，如果选用16进制双方都是用16进制显示，这样避免人工的转化，方便问题的定位 ...
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