零基础RT-thread第一节：串口通信UART

记录一下自己的学习过程，如有错误多多指教。

我使用的时野火的开发板，芯片是F767IGT6。

首先，写一个UART的c文件，配置一下UART。

/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2025-06-11     c       the first version
 */
#include <rtthread.h>

#define  SAMPLE_UART_NAME "uart1"

//用于接收消息的信号量
static struct rt_semaphore rx_sem;
static rt_device_t serial;

//接受数据回调函数
static rt_err_t uart_input(rt_device_t dev, rt_size_t size)
{
    rt_sem_release(&rx_sem);
    return RT_EOK;
}

static void serial_thread_entry(void *parameter)
{
    char ch;

    while(1)
    {
        //从串口读取一个字节的数据/没有读取到就等待接收信号量
        while(rt_device_read(serial, -1, &ch, 1) != 1)
        {
            //阻塞等待接收信号量/等到信号量 后再次读取数据
            rt_sem_take(&rx_sem, RT_WAITING_FOREVER);
        }
        //读取到的数据通过串口错位输出
        ch = ch + 1;
        rt_device_write(serial, 0, &ch, 1);
    }
}

static int uart_sample (int argc, char *argv[])
{
    rt_err_t ret = RT_EOK;
    char uart_name[RT_NAME_MAX];
    char str[] = "hello RT-Thread!\r\n";

    if(argc == 2)
    {
        rt_strncpy(uart_name, argv[1], RT_NAME_MAX);
    }
    else {
        rt_strncpy(uart_name, SAMPLE_UART_NAME, RT_NAME_MAX);
    }

    //查找系统中的串口设备
    serial = rt_device_find(uart_name);
    if (!serial)
    {
        rt_kprintf("find %s failed!\n", uart_name);
        return RT_ERROR;
    }
    //初始化信号量
    rt_sem_init(&rx_sem, "rx_sem", 0, RT_IPC_FLAG_FIFO);
    //以读写和中断接收方式打开串口设备
    rt_device_open(serial, RT_DEVICE_OFLAG_RDWR|RT_DEVICE_FLAG_INT_RX);
    //设置接收回调函数
    rt_device_set_rx_indicate(serial, uart_input);
    //发送字符串
    rt_device_write(serial, 0, str, sizeof(str) - 1);

    //创建serial线程
    rt_thread_t thread = rt_thread_create("serial",serial_thread_entry, RT_NULL, 1024, 25, 10);
    //创建成功则启动线程
    if( thread != RT_NULL)
    {
        rt_thread_startup(thread);
    }
    else {
        ret = RT_ERROR;
    }

    return ret;
}

MSH_CMD_EXPORT(uart_sample, uart device sample);

这里我们的串口是通过MSH_CMD,来调用的所以我们的main函数中是不需要调用函数的，所以main函数不用写任何的东西，然后uart.h文件其实也不用做什么，我这里声明了一个.c文件中的函数。

/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2025-06-11     c       the first version
 */
#ifndef APPLICATIONS_UART_H_
#define APPLICATIONS_UART_H_

int uart_sample(int argc, char *argv[]);

#endif /* APPLICATIONS_UART_H_ */

然后编译，下载。也没有报错。

接下来我打开RT终端准备测试一下串口。发现RT的 终端竟然没有反应。首先检查了串口的注册，是uart1没有问题，引脚也没有问题。在KEIL测试串口也是可以使用的。终端就是没有响应。而且

只显示了这些内容，很显然是系统根本没有启动，和硬件是没有关系的。
网上搜索最后发现问题：

刚创建的项目控制台为什么不能用
跟着做之后问题就解决了，真的很感谢这位老哥。

我们的串口也是测试成功，接下来让它控制一下LED：

/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2025-06-11     c            the first version
 * 2023-11-02     AI Assistant Add LED control via UART commands
 */
#include <rtthread.h>
#include <rtdevice.h>
#include <board.h>

#define SAMPLE_UART_NAME "uart1"

// 三色灯引脚定义 - 使用 GET_PIN 宏定义
#define LED_R_PIN    GET_PIN(H, 10)  // PH10 (122)
#define LED_G_PIN    GET_PIN(H, 11)  // PH11 (123)
#define LED_B_PIN    GET_PIN(H, 12)  // PH12 (124)

// 灯状态变量
static rt_base_t led_r_stat = PIN_HIGH;
static rt_base_t led_g_stat = PIN_HIGH;
static rt_base_t led_b_stat = PIN_HIGH;

// 用于接收消息的信号量
static struct rt_semaphore rx_sem;
static rt_device_t serial;

// 接受数据回调函数
static rt_err_t uart_input(rt_device_t dev, rt_size_t size)
{
    rt_sem_release(&rx_sem);
    return RT_EOK;
}

// 控制LED显示状态
static void ctrl_led_show(void)
{
    rt_pin_write(LED_R_PIN, led_r_stat);
    rt_pin_write(LED_G_PIN, led_g_stat);
    rt_pin_write(LED_B_PIN, led_b_stat);

    // 调试信息 - 输出当前LED状态
    rt_kprintf("LED Status: R:%d G:%d B:%d (Pins: %d, %d, %d)\n",
              led_r_stat == PIN_LOW,
              led_g_stat == PIN_LOW,
              led_b_stat == PIN_LOW,
              LED_R_PIN, LED_G_PIN, LED_B_PIN);
}

// 串口命令解释执行
static void process_uart_cmd(char cmd)
{
    char response[256];
    rt_size_t len = 0;

    switch (cmd)
    {
    case 'r': case 'R':   // 红灯开关
        led_r_stat = (led_r_stat == PIN_LOW) ? PIN_HIGH : PIN_LOW;
        len = rt_snprintf(response, sizeof(response), "Red LED: %s\r\n",
                          led_r_stat == PIN_LOW ? "ON" : "OFF");
        break;

    case 'g': case 'G':   // 绿灯开关
        led_g_stat = (led_g_stat == PIN_LOW) ? PIN_HIGH : PIN_LOW;
        len = rt_snprintf(response, sizeof(response), "Green LED: %s\r\n",
                          led_g_stat == PIN_LOW ? "ON" : "OFF");
        break;

    case 'b': case 'B':   // 蓝灯开关
        led_b_stat = (led_b_stat == PIN_LOW) ? PIN_HIGH : PIN_LOW;
        len = rt_snprintf(response, sizeof(response), "Blue LED: %s\r\n",
                          led_b_stat == PIN_LOW ? "ON" : "OFF");
        break;

    case '0':   // 所有灯关
        led_r_stat = PIN_HIGH;
        led_g_stat = PIN_HIGH;
        led_b_stat = PIN_HIGH;
        len = rt_snprintf(response, sizeof(response), "All LEDs OFF\r\n");
        break;

    case '1':   // 所有灯开(白色)
        led_r_stat = PIN_LOW;
        led_g_stat = PIN_LOW;
        led_b_stat = PIN_LOW;
        len = rt_snprintf(response, sizeof(response), "All LEDs ON (White)\r\n");
        break;

    case 'c': case 'C':   // 青色(绿+蓝)
        led_r_stat = PIN_HIGH;
        led_g_stat = PIN_LOW;
        led_b_stat = PIN_LOW;
        len = rt_snprintf(response, sizeof(response), "Cyan (Green+Blue)\r\n");
        break;

    case 'm': case 'M':   // 品红色(红+蓝)
        led_r_stat = PIN_LOW;
        led_g_stat = PIN_HIGH;
        led_b_stat = PIN_LOW;
        len = rt_snprintf(response, sizeof(response), "Magenta (Red+Blue)\r\n");
        break;

    case 'y': case 'Y':   // 黄色(红+绿)
        led_r_stat = PIN_LOW;
        led_g_stat = PIN_LOW;
        led_b_stat = PIN_HIGH;
        len = rt_snprintf(response, sizeof(response), "Yellow (Red+Green)\r\n");
        break;

    case '?':   // 帮助信息
        len = rt_snprintf(response, sizeof(response),
            "\r\nLED Control Commands:\r\n"
            "R - Toggle Red LED\r\n"
            "G - Toggle Green LED\r\n"
            "B - Toggle Blue LED\r\n"
            "0 - All OFF\r\n"
            "1 - All ON (White)\r\n"
            "C - Cyan (Green+Blue)\r\n"
            "M - Magenta (Red+Blue)\r\n"
            "Y - Yellow (Red+Green)\r\n"
            "Q - Help\r\n"
        );
        break;

    default:    // 无效命令
        len = rt_snprintf(response, sizeof(response), "Unknown command: %c\r\nUse ? for help\r\n", cmd);
        break;
    }

    // 更新LED状态
    ctrl_led_show();

    // 发送响应到串口
    if (len > 0 && len < sizeof(response)) {
        rt_device_write(serial, 0, response, len);
    }
}

static void serial_thread_entry(void *parameter)
{
    char ch;

    while (1)
    {
        // 从串口读取数据
        while (rt_device_read(serial, -1, &ch, 1) != 1)
        {
            // 等待接收信号量
            rt_sem_take(&rx_sem, RT_WAITING_FOREVER);
        }

        // 处理串口命令
        process_uart_cmd(ch);
    }
}

static int uart_sample(int argc, char *argv[])
{
    rt_err_t ret = RT_EOK;
    char uart_name[RT_NAME_MAX];
    char str[] = "\r\nUART LED Controller Ready!\r\n"
                 "Using LEDs on PH10 (R), PH11 (G), PH12 (B)\r\n"
                 "Enter ? for help\r\n";

    // 初始化LED引脚
    rt_pin_mode(LED_R_PIN, PIN_MODE_OUTPUT);
    rt_pin_mode(LED_G_PIN, PIN_MODE_OUTPUT);
    rt_pin_mode(LED_B_PIN, PIN_MODE_OUTPUT);

    // 设置初始状态为关闭
    led_r_stat = PIN_HIGH;
    led_g_stat = PIN_HIGH;
    led_b_stat = PIN_HIGH;
    ctrl_led_show();

    // 输出调试信息
    rt_kprintf("Initialized LEDs:\n");
    rt_kprintf("  Red   - PH10 (Pin %d)\n", LED_R_PIN);
    rt_kprintf("  Green - PH11 (Pin %d)\n", LED_G_PIN);
    rt_kprintf("  Blue  - PH12 (Pin %d)\n", LED_B_PIN);

    // 获取串口设备名称
    if (argc == 2) {
        rt_strncpy(uart_name, argv[1], RT_NAME_MAX);
    } else {
        rt_strncpy(uart_name, SAMPLE_UART_NAME, RT_NAME_MAX);
    }

    // 查找串口设备
    serial = rt_device_find(uart_name);
    if (!serial) {
        rt_kprintf("find %s failed!\n", uart_name);
        return RT_ERROR;
    }

    // 初始化信号量
    rt_sem_init(&rx_sem, "rx_sem", 0, RT_IPC_FLAG_FIFO);

    // 打开串口设备
    if (rt_device_open(serial, RT_DEVICE_OFLAG_RDWR | RT_DEVICE_FLAG_INT_RX) != RT_EOK) {
        rt_kprintf("open %s failed!\n", uart_name);
        return RT_ERROR;
    }

    // 设置串口参数（可选，根据需要设置）
    struct serial_configure config = RT_SERIAL_CONFIG_DEFAULT;
    config.baud_rate = BAUD_RATE_115200;  // 115200bps
    config.data_bits = DATA_BITS_8;       // 8位数据位
    config.stop_bits = STOP_BITS_1;       // 1位停止位
    config.bufsz = 64;                    // 接收缓冲区大小
    config.parity = PARITY_NONE;          // 无校验
    rt_device_control(serial, RT_DEVICE_CTRL_CONFIG, &config);

    // 设置接收回调函数
    rt_device_set_rx_indicate(serial, uart_input);

    // 发送欢迎信息
    rt_device_write(serial, 0, str, sizeof(str) - 1);

    // 创建串口处理线程
    rt_thread_t thread = rt_thread_create("serial", serial_thread_entry, RT_NULL,
                                         1024, 25, 10);

    // 启动线程
    if (thread != RT_NULL) {
        rt_thread_startup(thread);
    } else {
        rt_kprintf("Failed to create serial thread!\n");
        ret = RT_ERROR;
    }

    return ret;
}

MSH_CMD_EXPORT(uart_sample, uart device sample);

只改变uart.c即可。其他文件不变。
测试后一切正常。