rtthread stm32的双串口程序

下面是一个基于 RT-Thread 的 STM32 双串口程序的示例：

#include <rtthread.h>
#include <board.h>

#define USART1_BUFSZ    256
#define USART2_BUFSZ    256

#define USART1_NAME     "uart1"
#define USART2_NAME     "uart2"

static rt_uint8_t usart1_rx_buf[USART1_BUFSZ];
static rt_uint8_t usart1_tx_buf[USART1_BUFSZ];
static rt_uint8_t usart2_rx_buf[USART2_BUFSZ];
static rt_uint8_t usart2_tx_buf[USART2_BUFSZ];

static struct rt_serial_device usart1;
static struct rt_serial_device usart2;

static void usart1_rx_ind(rt_device_t dev, rt_size_t size)
{
    rt_kprintf("usart1_rx_ind: size = %d\n", size);
}

static void usart2_rx_ind(rt_device_t dev, rt_size_t size)
{
    rt_kprintf("usart2_rx_ind: size = %d\n", size);
}

int usart_init(void)
{
    /* Init USART1 */
    rt_memset(&usart1, 0, sizeof(usart1));
    usart1.config.baud_rate = BAUD_RATE_115200;
    usart1.config.data_bits = DATA_BITS_8;
    usart1.config.parity = PARITY_NONE;
    usart1.config.stop_bits = STOP_BITS_1;
    usart1.config.bufsz = USART1_BUFSZ;
    usart1.config.rx_indicate = usart1_rx_ind;
    usart1.config.tx_complete = RT_NULL;
    usart1.config.rx_buffer = usart1_rx_buf;
    usart1.config.tx_buffer = usart1_tx_buf;
    usart1.parent.user_data = RT_NULL;
    return rt_serial_register(&usart1, USART1_NAME, RT_DEVICE_FLAG_RDWR);
    
    /* Init USART2 */
    rt_memset(&usart2, 0, sizeof(usart2));
    usart2.config.baud_rate = BAUD_RATE_115200;
    usart2.config.data_bits = DATA_BITS_8;
    usart2.config.parity = PARITY_NONE;
    usart2.config.stop_bits = STOP_BITS_1;
    usart2.config.bufsz = USART2_BUFSZ;
    usart2.config.rx_indicate = usart2_rx_ind;
    usart2.config.tx_complete = RT_NULL;
    usart2.config.rx_buffer = usart2_rx_buf;
    usart2.config.tx_buffer = usart2_tx_buf;
    usart2.parent.user_data = RT_NULL;
    return rt_serial_register(&usart2, USART2_NAME, RT_DEVICE_FLAG_RDWR);
}

int main(void)
{
    usart_init();

    /* Open USART1 */
    rt_device_t dev1 = rt_device_find(USART1_NAME);
    rt_device_open(dev1, RT_DEVICE_FLAG_INT_RX);

    /* Open USART2 */
    rt_device_t dev2 = rt_device_find(USART2_NAME);
    rt_device_open(dev2, RT_DEVICE_FLAG_INT_RX);

    /* Send data through USART1 */
    rt_device_write(dev1, 0, "Hello, USART1!", strlen("Hello, USART1!"));

    /* Send data through USART2 */
    rt_device_write(dev2, 0, "Hello, USART2!", strlen("Hello, USART2!"));

    return RT_EOK;
}

在这个例子中，我们使用了 RT-Thread 的串口设备驱动，并且使用了两个串口设备 USART1 和 USART2。我们通过 `usart_init` 函数初始化了这两个设备，并且通过 `rt_serial_register` 函数注册到 RT-Thread 的设备管理器中。

在 `main` 函数中，我们打开了 USART1 和 USART2 设备，并且通过 `rt_device_write` 函数分别向这两个设备发送了一条消息。当接收到数据时，回调函数 `usart1_rx_ind` 和 `usart2_rx_ind` 会被调用，分别输出接收到的数据长度。

需要注意的是，在实际使用中，需要根据具体的硬件配置和需求进行修改。