rtthread 添加串口 (uart2)

查询uart配置过程

文件路径： /drivers/board.h

/** 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
 *
 */

1. 使能RTT uart驱动

   使能rtt lwip协议栈
   打开 RT-Thread Settings-->跟多配置
   |组件
   |---->RT-Thrad组件
   |		|---->设备驱动程序
   |			|---->使能UART设备驱动程序		√	
   

2. 使能I2C总线

   打开 /drivers/board.h 
   #define BSP_USING_UART2                  //使用串口2
   #define BSP_UART2_TX_PIN       "PA2"     //串口2的Tx脚为 PA2
   #define BSP_UART2_RX_PIN       "PA3"     //串口2的Rx脚为 PA3
   #endif
   	```
   
   
   

3. 使能HAL库相应模块

打开 /drivers/ stm32f7xx_hal_conf.h
使能 #define HAL_UART_MODULE_ENABLED

4. 添加硬件初始化代码
   通过 stm32cubemx工具使能uart2硬件，在一下路径
   \Core\Src\stm32f7xx_hal_msp.c中将HAL_UART_MspInit拷贝到 /drivers/board.c中

void HAL_UART_MspInit(UART_HandleTypeDef* uartHandle)
{

  GPIO_InitTypeDef GPIO_InitStruct = {0};
  if(uartHandle->Instance==USART2)
  {

    /* USART2 clock enable */
    __HAL_RCC_USART2_CLK_ENABLE();

    __HAL_RCC_GPIOA_CLK_ENABLE();
    /**USART2 GPIO Configuration
    PA2     ------> USART2_TX
    PA3     ------> USART2_RX
    */
    GPIO_InitStruct.Pin = GPIO_PIN_2;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    GPIO_InitStruct.Pin = GPIO_PIN_3;
    GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
  }
}

5. 验证

msh />list_device
device           type         ref count
-------- -------------------- ----------
uart2    Character Device     1	

6. 测试代码

#include 
#define SAMPLE_UART_NAME       "uart2"
/* 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;
}

/**
 * 串口接受线程
 * @param parameter
 */
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;
}
/* 导出到 msh 命令列表中 */
MSH_CMD_EXPORT(uart_sample, uart device sample);