5 如果使用UART1作为控制台输出，还可以使用UART1做其他通讯口吗？

发布于 2022-08-12 16:35:45 浏览：593 订阅该版

crystal266 2022-08-12

嵌入式

强烈不建议这么做，运行 RT-Thread 操作系统最好单独留一个串口作为控制台的串口，在控制台中可以方便的看出来线程、定时器、信号量、互斥锁、内存等关键信息的运行情况，更方便监控整个系统的运行。

控制台线程的执行代码在文件 rt-thread\components\finsh\shell.c 里面，如下所示。从中可以看出改线程在一直获取控制台串口的输入数据，也就是说该串口一收到数据就会被该线程读出来（该线程的优先级是 20），收到 "\r\n" 之后开始解析命令并执行对应的操作。如果将控制台串口和其他通讯功能合为一个，想实现除了解析命令还解析其他协议的话，那么就需要修改该函数的实现，如果修改不好会影响到控制台命令的解析，建议硬件设计时单独留出来一个串口作为控制台串口使用。
```c
void finsh_thread_entry(void *parameter)
{
    int ch;

/* normal is echo mode */
#ifndef FINSH_ECHO_DISABLE_DEFAULT
    shell->echo_mode = 1;
#else
    shell->echo_mode = 0;
#endif

#if !defined(RT_USING_POSIX) && defined(RT_USING_DEVICE)
    /* set console device as shell device */
    if (shell->device == RT_NULL)
    {
        rt_device_t console = rt_console_get_device();
        if (console)
        {
            finsh_set_device(console->parent.name);
        }
    }
#endif

#ifdef FINSH_USING_AUTH
    /* set the default password when the password isn't setting */
    if (rt_strlen(finsh_get_password()) == 0)
    {
        if (finsh_set_password(FINSH_DEFAULT_PASSWORD) != RT_EOK)
        {
            rt_kprintf("Finsh password set failed.\n");
        }
    }
    /* waiting authenticate success */
    finsh_wait_auth();
#endif

rt_kprintf(FINSH_PROMPT);

while (1)
    {
        ch = (int)finsh_getchar();
        if (ch < 0)
        {
            continue;
        }

/*
         * handle control key
         * up key  : 0x1b 0x5b 0x41
         * down key: 0x1b 0x5b 0x42
         * right key:0x1b 0x5b 0x43
         * left key: 0x1b 0x5b 0x44
         */
        if (ch == 0x1b)
        {
            shell->stat = WAIT_SPEC_KEY;
            continue;
        }
        else if (shell->stat == WAIT_SPEC_KEY)
        {
            if (ch == 0x5b)
            {
                shell->stat = WAIT_FUNC_KEY;
                continue;
            }

shell->stat = WAIT_NORMAL;
        }
        else if (shell->stat == WAIT_FUNC_KEY)
        {
            shell->stat = WAIT_NORMAL;

if (ch == 0x41) /* up key */
            {
#ifdef FINSH_USING_HISTORY
                /* prev history */
                if (shell->current_history > 0)
                    shell->current_history --;
                else
                {
                    shell->current_history = 0;
                    continue;
                }

/* copy the history command */
                memcpy(shell->line, &shell->cmd_history[shell->current_history][0],
                       FINSH_CMD_SIZE);
                shell->line_curpos = shell->line_position = strlen(shell->line);
                shell_handle_history(shell);
#endif
                continue;
            }
            else if (ch == 0x42) /* down key */
            {
#ifdef FINSH_USING_HISTORY
                /* next history */
                if (shell->current_history < shell->history_count - 1)
                    shell->current_history ++;
                else
                {
                    /* set to the end of history */
                    if (shell->history_count != 0)
                        shell->current_history = shell->history_count - 1;
                    else
                        continue;
                }

memcpy(shell->line, &shell->cmd_history[shell->current_history][0],
                       FINSH_CMD_SIZE);
                shell->line_curpos = shell->line_position = strlen(shell->line);
                shell_handle_history(shell);
#endif
                continue;
            }
            else if (ch == 0x44) /* left key */
            {
                if (shell->line_curpos)
                {
                    rt_kprintf("\b");
                    shell->line_curpos --;
                }

continue;
            }
            else if (ch == 0x43) /* right key */
            {
                if (shell->line_curpos < shell->line_position)
                {
                    rt_kprintf("%c", shell->line[shell->line_curpos]);
                    shell->line_curpos ++;
                }

continue;
            }
        }

/* received null or error */
        if (ch == '\0' || ch == 0xFF) continue;
        /* handle tab key */
        else if (ch == '\t')
        {
            int i;
            /* move the cursor to the beginning of line */
            for (i = 0; i < shell->line_curpos; i++)
                rt_kprintf("\b");

/* auto complete */
            shell_auto_complete(&shell->line[0]);
            /* re-calculate position */
            shell->line_curpos = shell->line_position = strlen(shell->line);

continue;
        }
        /* handle backspace key */
        else if (ch == 0x7f || ch == 0x08)
        {
            /* note that shell->line_curpos >= 0 */
            if (shell->line_curpos == 0)
                continue;

shell->line_position--;
            shell->line_curpos--;

if (shell->line_position > shell->line_curpos)
            {
                int i;

rt_memmove(&shell->line[shell->line_curpos],
                           &shell->line[shell->line_curpos + 1],
                           shell->line_position - shell->line_curpos);
                shell->line[shell->line_position] = 0;

rt_kprintf("\b%s  \b", &shell->line[shell->line_curpos]);

/* move the cursor to the origin position */
                for (i = shell->line_curpos; i <= shell->line_position; i++)
                    rt_kprintf("\b");
            }
            else
            {
                rt_kprintf("\b \b");
                shell->line[shell->line_position] = 0;
            }

continue;
        }

/* handle end of line, break */
        if (ch == '\r' || ch == '\n')
        {
#ifdef FINSH_USING_HISTORY
            shell_push_history(shell);
#endif
            if (shell->echo_mode)
                rt_kprintf("\n");
            msh_exec(shell->line, shell->line_position);

rt_kprintf(FINSH_PROMPT);
            memset(shell->line, 0, sizeof(shell->line));
            shell->line_curpos = shell->line_position = 0;
            continue;
        }

/* it's a large line, discard it */
        if (shell->line_position >= FINSH_CMD_SIZE)
            shell->line_position = 0;

/* normal character */
        if (shell->line_curpos < shell->line_position)
        {
            int i;

rt_memmove(&shell->line[shell->line_curpos + 1],
                       &shell->line[shell->line_curpos],
                       shell->line_position - shell->line_curpos);
            shell->line[shell->line_curpos] = ch;
            if (shell->echo_mode)
                rt_kprintf("%s", &shell->line[shell->line_curpos]);

/* move the cursor to new position */
            for (i = shell->line_curpos; i < shell->line_position; i++)
                rt_kprintf("\b");
        }
        else
        {
            shell->line[shell->line_position] = ch;
            if (shell->echo_mode)
                rt_kprintf("%c", ch);
        }

ch = 0;
        shell->line_position ++;
        shell->line_curpos++;
        if (shell->line_position >= FINSH_CMD_SIZE)
        {
            /* clear command line */
            shell->line_position = 0;
            shell->line_curpos = 0;
        }
    } /* end of device read */
}
```