RT_Thread_配置串口3、利用例程验证

1、配置board.h的串口3

打开board.h文件，找到串口这一段，就是在这里增加串口3的配置，先看一下注释中的说明。

• 1、宏定义串口号
• 2、宏定义相对应的发送和接收引脚号
• 3、如果使用DMA，要在RT-Thread Settings里配置
• 4、根据串口号和发送接收定义DMA功能

所以我们配置串口3只需要第1、2步，新增在之前的串口1下方。 

/*-------------------------- UART CONFIG BEGIN --------------------------*/
 
/** After configuring corresponding UART or UART DMA, you can use it.
 *
 * STEP 1, define macro define related to the serial port opening based on the serial port number
 *                 such as     #define BSP_USING_UART1
 *
 * STEP 2, according to the corresponding pin of serial port, define the related serial port information macro
 *                 such as     #define BSP_UART1_TX_PIN       "PA9"
 *                             #define BSP_UART1_RX_PIN       "PA10"
 *
 * STEP 3, if you want using SERIAL DMA, you must open it in the RT-Thread Settings.
 *                 RT-Thread Setting -> Components -> Device Drivers -> Serial Device Drivers -> Enable Serial DMA Mode
 *
 * STEP 4, according to serial port number to define serial port tx/rx DMA function in the board.h file
 *                 such as     #define BSP_UART1_RX_USING_DMA
 *
 */
 
#define BSP_USING_UART1
#define BSP_UART1_TX_PIN       "PA9"
#define BSP_UART1_RX_PIN       "PA10"

#define BSP_USING_UART3
#define BSP_UART3_TX_PIN       "PB10"
#define BSP_UART3_RX_PIN       "PB11"
 
/*-------------------------- UART CONFIG END --------------------------*/

 

2、代码及运行结果

2.1、复制官方例程到main.c里

//#include <rtthread.h>

#define SAMPLE_UART_NAME       "uart3"

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

/* 接收数据回调函数 */
static rt_err_t uart_input(rt_device_t dev, rt_size_t size)
{
    /* 串口接收到数据后产生中断，调用此回调函数，然后发送接收信号量 */
    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，没有读取到则等待接收信号量 */
        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);
    /* 以中断接收及轮询发送模式打开串口设备 */
    rt_device_open(serial, 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;
}

2.2、在main()中调用

uart_sample(1,"uart3");

2.3、测试

• 硬件连接：需要一个USB转串口模块，TX接串口3的RX（PB11），RX接串口3的TX（PB10）；
• 串口助手：选好USB转串口的串口号，波特率115200，8位数据位，1位停止位，无校验位；

发送"12345"，会返回"23456"就是成功的，因为例程里就是把接收到的每个字节数据加1后再用串口发送出去;