rt_thread系统 串口5收发任意长度数据

#include 
#include 
#include 

/* 串口设备句柄 */
 rt_device_t uart5_dev;
static struct rt_semaphore rx_sem5;
static struct rt_semaphore end_sem;
static char rx_buf[100];
static int num = 0;

/* 消息队列控制块 */
volatile rt_size_t rx_size;

static rt_err_t uart_input(rt_device_t dev, rt_size_t size)
{
	rt_timer_stop(timer);
	
	rt_sem_release(&rx_sem5);	
	return RT_EOK;
}


static void uart5_rx_thread(void *parameter)
{
    rt_size_t size = 0;
	char ch = 0;

    while (1)
    {    	
    	rt_sem_take(&rx_sem5, RT_WAITING_FOREVER);
		
        size = rt_device_read(uart5_dev, 0, &ch, 1);
        if(size == 0)
        {
        	rt_kprintf("read uart5 fail\n");
        	continue;
        }
		rx_buf[num++] = ch;
		rt_timer_start(timer);
		
		rt_kprintf("%d\n", (uint16_t )ch);
    }
	rt_device_close(uart5_dev);
}


static void uart5_tx_thread(void *parameter)
{
	rt_size_t size = 0;
	while(1)
	{
		rt_sem_take(&end_sem, RT_WAITING_FOREVER);

		size = rt_device_write(uart5_dev, 0, rx_buf, num);
		if(size == 0)
        {
        	rt_kprintf("write uart5 fail\n");
        	continue;
        }
		rt_memset(rx_buf, 0, sizeof(rx_buf));
		num = 0;
	}
	return ;
}

static void timeout(void *parameter)
{
	rt_sem_release(&end_sem);
	
	rt_timer_stop(timer);
}


int main(void)
{
    rt_err_t ret;

    char str[] = "hello RT-Thread!";

	uart5_dev= rt_device_find("uart5");
	if(uart5_dev == RT_NULL)
	{
		rt_kprintf("find uart5 fail\n");
		return RT_ERROR;
	}

	ret = rt_device_open(uart5_dev, RT_DEVICE_OFLAG_RDWR | RT_DEVICE_FLAG_INT_RX | RT_DEVICE_FLAG_STREAM | RT_DEVICE_FLAG_DMA_RX); 						   
	if(ret != RT_EOK)
	{
		rt_kprintf("open uart5 fail\n");
		return RT_ERROR;
	}

	rt_sem_init(&end_sem, "rx_sem5", 0, RT_IPC_FLAG_FIFO);
	rt_sem_init(&rx_sem5, "rx_sem5", 0, RT_IPC_FLAG_FIFO);

    /* 设置接收回调函数 */
    rt_device_set_rx_indicate(uart5_dev, uart_input);
	
    /* 发送字符串 */
    rt_size_t size = rt_device_write(uart5_dev, 0, str, (sizeof(str) - 1));
    if(size == 0)
    {
    	rt_kprintf("write uart fail\n");
    	return RT_ERROR;
    }
 
    /* 创建 serial 线程 */
    rt_thread_t rx_thread = rt_thread_create("serial", uart5_rx_thread, RT_NULL, 1024, 25, 10);
    if (rx_thread == RT_NULL)
    {
    	rt_kprintf("thread create fail\n");
        return RT_ERROR;
    }
    rt_thread_startup(rx_thread);

	rt_thread_t tx_thread = rt_thread_create("serial", uart5_tx_thread, RT_NULL, 1024, 25, 10);
    if (tx_thread == RT_NULL)
    {
    	rt_kprintf("thread create fail\n");
        return RT_ERROR;
    }
    rt_thread_startup(tx_thread);

	/* 创建  周期定时器 */
    timer = rt_timer_create("timer", timeout,
                             RT_NULL, 200,
                             RT_TIMER_FLAG_PERIODIC);
	if(timer == RT_NULL)
    {
    	rt_kprintf("timer create fail\n");
        return RT_ERROR;
    }

    return RT_EOK;
}

注意：数据接收最好使用中断+DMA方式，不然在接收大量数据时，容易出现数据丢失问题！！！