两块STM32串口通信使用RT-Thread邮箱例子

以下是两块STM32使用RT-Thread邮箱进行串口通信的简单示例：

在第一块STM32中，我们需要使用邮箱发送数据：

#include <rtthread.h>
#include <rtdevice.h>

static rt_mailbox_t mb = RT_NULL;

void uart1_rx_thread_entry(void *parameter)
{
    rt_device_t device;
    rt_uint8_t buff[16];
    rt_size_t size;

    device = rt_device_find("uart1");
    if(device == RT_NULL)
    {
        rt_kprintf("Can't find uart1\n");
        return;
    }

    while(1)
    {
        rt_memset(buff, 0, sizeof(buff));
        size = rt_device_read(device, 0, buff, sizeof(buff));
        rt_mb_send(mb, (rt_uint32_t)buff, size);
    }
}

int main(void)
{
    rt_thread_t thread;

    rt_kprintf("Starting uart1_rx_thread...\n");
    mb = rt_mb_create("mb", 10, RT_IPC_FLAG_FIFO);
    thread = rt_thread_create("uart1_rx", uart1_rx_thread_entry, RT_NULL, 1024, 8, 20);
    if(thread != RT_NULL)
    {
        rt_thread_startup(thread);
    }

    while(1)
    {
        rt_kprintf("Hello, world!\n");
        rt_thread_delay(1000);
    }
}

在第二块STM32中，我们需要使用邮箱接收数据：

#include <rtthread.h>
#include <rtdevice.h>

static rt_mailbox_t mb = RT_NULL;

void uart1_tx_thread_entry(void *parameter)
{
    rt_device_t device;
    rt_uint8_t buff[16];
    rt_size_t size;

    device = rt_device_find("uart1");
    if(device == RT_NULL)
    {
        rt_kprintf("Can't find uart1\n");
        return;
    }

    while(1)
    {
        rt_memset(buff, 0, sizeof(buff));
        size = rt_mb_recv(mb, (rt_uint32_t *)buff, sizeof(buff), RT_WAITING_FOREVER);
        rt_device_write(device, 0, buff, size);
    }
}

int main(void)
{
    rt_thread_t thread;

    rt_kprintf("Starting uart1_tx_thread...\n");
    mb = rt_mb_create("mb", 10, RT_IPC_FLAG_FIFO);
    thread = rt_thread_create("uart1_tx", uart1_tx_thread_entry, RT_NULL, 1024, 8, 20);
    if(thread != RT_NULL)
    {
        rt_thread_startup(thread);
    }

    while(1)
    {
        rt_kprintf("Hello, world!\n");
        rt_thread_delay(1000);
    }
}

当第一块STM32从串口接收到数据时，它会将数据发送到邮箱中。第二块STM32会从邮箱中接收数据并将其发送到串口中。这样，两块STM32就完成了串口通信。