使用HAL库做串口接收数据，复位后第一个字节接收不到

popppepn

1. /**
   
2.   * @brief Receive an amount of data in blocking mode.
   
3.   * @param huart UART handle.
   
4.   * @param pData pointer to data buffer.
   
5.   * @param Size amount of data to be received.
   
6.   * @param Timeout Timeout duration.
   
7.   * [url=home.php?mod=space&uid=60778]@note[/url]   When UART parity is not enabled (PCE = 0), and Word Length is configured to 9 bits (M1-M0 = 01),
   
8.   *         address of user data buffer for storing data to be received, should be aligned on a half word frontier (16 bits)
   
9.   *         (as received data will be handled using u16 pointer cast). Depending on compilation chain,
   
10.   *         use of specific alignment compilation directives or pragmas might be required to ensure proper alignment for pData.
    
11.   * @retval HAL status
    
12.   */
    
13. HAL_StatusTypeDef HAL_UART_Receive(UART_HandleTypeDef *huart, uint8_t *pData, uint16_t Size, uint32_t Timeout)
    
14. {
    
15.   uint16_t* tmp;
    
16.   uint16_t uhMask;
    
17.   uint32_t tickstart = 0;
    
18. 
    
19.   /* Check that a Rx process is not already ongoing */
    
20.   if(huart->RxState == HAL_UART_STATE_READY)                    <font color="#ff0000">//这里进不去，发送第二个字节才能进，应该在配置上加什么样的初始化</font>
    
21.   {
    
22.     if((pData == NULL ) || (Size == 0U))
    
23.     {
    
24.       return  HAL_ERROR;
    
25.     }
    
26. 
    
27.     /* In case of 9bits/No Parity transfer, pData buffer provided as input paramter
    
28.        should be aligned on a u16 frontier, as data to be received from RDR will be
    
29.        handled through a u16 cast. */
    
30.     if ((huart->Init.WordLength == UART_WORDLENGTH_9B) && (huart->Init.Parity == UART_PARITY_NONE))
    
31.     {
    
32.       if((((uint32_t)pData)&1U) != 0U)
    
33.       {
    
34.         return  HAL_ERROR;
    
35.       }
    
36.     }
    
37. 
    
38.     /* Process Locked */
    
39.     __HAL_LOCK(huart);
    
40. 
    
41.     huart->ErrorCode = HAL_UART_ERROR_NONE;
    
42.     huart->RxState = HAL_UART_STATE_BUSY_RX;
    
43. 
    
44.     /* Init tickstart for timeout managment*/
    
45.     tickstart = HAL_GetTick();
    
46. 
    
47.     huart->RxXferSize = Size;
    
48.     huart->RxXferCount = Size;
    
49. 
    
50.     /* Computation of UART mask to apply to RDR register */
    
51.     UART_MASK_COMPUTATION(huart);
    
52.     uhMask = huart->Mask;
    
53. 
    
54.     /* as long as data have to be received */
    
55.     while(huart->RxXferCount > 0U)
    
56.     {
    
57.       huart->RxXferCount--;
    
58.       if(UART_WaitOnFlagUntilTimeout(huart, UART_FLAG_RXNE, RESET, tickstart, Timeout) != HAL_OK)
    
59.       {
    
60.         return HAL_TIMEOUT;
    
61.       }
    
62.       if ((huart->Init.WordLength == UART_WORDLENGTH_9B) && (huart->Init.Parity == UART_PARITY_NONE))
    
63.       {
    
64.         tmp = (uint16_t*) pData ;
    
65.         *tmp = (uint16_t)(huart->Instance->RDR & uhMask);
    
66.         pData +=2U;
    
67.       }
    
68.       else
    
69.       {
    
70.         *pData++ = (uint8_t)(huart->Instance->RDR & (uint8_t)uhMask);
    
71.       }
    
72.     }
    
73. 
    
74.     /* At end of Rx process, restore huart->RxState to Ready */
    
75.     huart->RxState = HAL_UART_STATE_READY;
    
76. 
    
77.     /* Process Unlocked */
    
78.     __HAL_UNLOCK(huart);
    
79. 
    
80.     return HAL_OK;
    
81.   }
    
82.   else
    
83.   {
    
84.     return HAL_BUSY;
    
85.   }
    
86. }

复制代码

popppepn

在初始化的时候，加上        HAL_UART_Receive_IT(&UART2_Handler, (uint8_t *)&aRxBuffer, 1);        同样会进入 HAL_BUSY