利用rt-thread已经串口通讯的问题

也至 · 发表于 2016-4-26 17:16:59

这个程序为什么每次都读写一个字符，但最后能够完成多字符传输

#include <rtthread.h>

struct rx_msg
{
  rt_device_t dev;
  rt_size_t size;
};
/* 用于接收消息的消息队列*/
static rt_mq_t rx_mq;
/* 接收线程的接收缓冲区*/
static char uart_rx_buffer[512];
static char uart_sx_buffer[512];
/* 数据到达回调函数*/
rt_err_t uart_input(rt_device_t dev, rt_size_t size)
{
  struct rx_msg msg;
  msg.dev = dev;
  msg.size = size;

  /* 发送消息到消息队列中*/
  rt_mq_send(rx_mq, &msg, sizeof(struct rx_msg));

  return RT_EOK;
}

void device_thread_entry(void* parameter)
{
  struct rx_msg msg;
  int count = 0;
  rt_device_t device, write_device;
  rt_err_t result = RT_EOK;

  /* 查找系统中的串口1设备 */
  device = rt_device_find("uart1");
  if (device!= RT_NULL)
  {
/* 设置回调函数及打开设备*/
rt_device_set_rx_indicate(device, uart_input);
rt_device_open(device, RT_DEVICE_OFLAG_RDWR);
  }
  /* 设置写设备为uart1设备 */
  write_device = device;

  /* 查找系统中的串口2设备 */
  device= rt_device_find("uart2");
  if (device != RT_NULL)
  {
/* 设置回调函数及打开设备*/
rt_device_set_rx_indicate(device, uart_input);
rt_device_open(device, RT_DEVICE_OFLAG_RDWR);
  }

  while (1)
  {
/* 从消息队列中读取消息*/
result = rt_mq_recv(rx_mq, &msg,
   sizeof(struct rx_msg), 50);
// if (result == -RT_ETIMEOUT)
// {
//    /* 接收超时*/
//    rt_kprintf("timeout count:%d\n", ++count);
// }
//
/* 成功收到消息*/
if (result == RT_EOK)
{
   rt_uint32_t rx_length;
   rx_length = (sizeof(uart_rx_buffer) - 1) >
msg.size ? msg.size : sizeof(uart_rx_buffer) - 1;

   /* 读取消息*/
   rx_length = rt_device_read(msg.dev, 0,
&uart_rx_buffer[0], rx_length);
   uart_rx_buffer[rx_length] = '\0';

   /* 写到写设备中*/
   if (write_device != RT_NULL)
      rt_device_write(write_device, 0,
&uart_rx_buffer[0], rx_length);
}
  }
}

static struct rt_messagequeue s_your_mq;//消息队列控制块对象
static char s_msg_pool[1024];//消息池

int rt_application_init()
{

/* 创建devt线程*/
  rt_thread_t thread = rt_thread_create("devt",
device_thread_entry, RT_NULL,
1024, 25, 7);

   rt_mq_init(&s_your_mq,"test",&s_msg_pool[0],sizeof(struct rx_msg),sizeof(s_msg_pool),RT_IPC_FLAG_FIFO);//初始化消息队列控制块
  rx_mq =&s_your_mq;//将rx_mq再指向s_your_mq
  /* 创建成功则启动线程*/
  if (thread != RT_NULL)
rt_thread_startup(thread);
}