Question

我是linux上嵌入式系统的新手。我从我的friendlyARM KIT，tiny6410上的一个简单的串行通信程序开始，我遇到了这个问题。这是我的代码：

#include <stdio.h>  // standard input / output functions
#include <stdlib.h>
#include <string.h>     // string function definitions
#include <unistd.h>     // UNIX standard function definitions
#include <fcntl.h>  // File control definitions
#include <errno.h>  // Error number definitions
#include <termios.h>    // POSIX terminal control definitionss
#include <sys/time.h>   // time calls
#include <string.h>

/* Ten file thiet bi cong com
- tren PC: /dev/ttyUSB0 (USB2COM)
- tren KIT: /dev/ttyS0;
*/

int main(int argc, char** argv)
{
    char ch;
    int fd;// n;
    char *DeviceName;
    struct termios port_settings; //Cau truc de luu tru cau hinh uart

if(argc>1)
{
    DeviceName = (char*)malloc(strlen(argv[1])+1);
    strcpy(DeviceName, argv[1]); //Lay tham so nhap vao
    //printf("Device Name=%s\n", DeviceName);
}
else
    DeviceName = "/dev/ttyUSB0"; //Cong com mac dinh
//Open com port
fd = open(DeviceName, O_RDWR | O_NOCTTY | O_NDELAY);
if(fd<0)
{
    printf("Open com port %s failed\n", DeviceName);
    return fd;
}
fcntl(fd, F_SETFL, FNDELAY);  /* Configure port reading */

//Cau hinh tham so com port
//baudrate 9600, 8N1
cfsetispeed(&port_settings, B9600);
cfsetospeed(&port_settings, B9600);

port_settings.c_cflag &= ~PARENB;   //Set no parity
port_settings.c_cflag &= ~CSTOPB;   //Set 1 stop bit
port_settings.c_cflag &= ~CSIZE;    //Set 8 bit data using mask bit
port_settings.c_cflag |= CS8;
port_settings.c_cflag &= ~CRTSCTS;  //No hadware hanshaking

tcsetattr(fd, TCSANOW, &port_settings); // apply the settings to the port

while(1)
{
    char key = getchar();
    ch = key;
    write(fd, &ch, 1);
}

close(fd);
return 0;

}

我得到“open com port / dev / ttyUSB0 failed”错误消息。

Answer 1

您应该尝试通过指定/dev/ttyS0来运行代码，因为通常主板的串口具有此设备名称，您还必须以root权限运行您的二进制文件

在Linux上使用FriendlyARM KIT进行串行通信

1 个答案: