STM32H7定时器输入捕获功能实现

eric2013

说明：

通过输入捕获功能可以测量脉宽和信号周期，占空比等信息。

测试的官方例子：TIM_InputCapture



使用的定时器1的CC2。

最新分辨率是200 MHz / 65535 ≈ 3051Hz

代码如下：

1. int main(void)
   
2. {
   
3.   /* Enable the CPU Cache */
   
4.   CPU_CACHE_Enable();
   
5. 
   
6.   /* STM32H7xx HAL library initialization:
   
7.        - Systick timer is configured by default as source of time base, but user
   
8.          can eventually implement his proper time base source (a general purpose
   
9.          timer for example or other time source), keeping in mind that Time base
   
10.          duration should be kept 1ms since PPP_TIMEOUT_VALUEs are defined and
    
11.          handled in milliseconds basis.
    
12.        - Set NVIC Group Priority to 4
    
13.        - Low Level Initialization
    
14.      */
    
15.   HAL_Init();
    
16. 
    
17.   /* Configure the system clock to 400 MHz */
    
18.   SystemClock_Config();
    
19. 
    
20.   /*##-1- Configure the TIM peripheral #######################################*/
    
21.   /* TIM1 configuration: Input Capture mode ---------------------
    
22.      The external signal is connected to TIM1 CH2 pin (PE.11)  
    
23.      The Rising edge is used as active edge,
    
24.      The TIM1 CCR2 is used to compute the frequency value
    
25.   ------------------------------------------------------------ */
    
26. 
    
27.   /* Set TIMx instance */
    
28.   TimHandle.Instance = TIMx;
    
29. 
    
30.   /* Initialize TIMx peripheral as follows:
    
31.        + Period = 0xFFFF
    
32.        + Prescaler = 0
    
33.        + ClockDivision = 0
    
34.        + Counter direction = Up
    
35.   */
    
36.   TimHandle.Init.Period            = 0xFFFF;
    
37.   TimHandle.Init.Prescaler         = 0;
    
38.   TimHandle.Init.ClockDivision     = 0;
    
39.   TimHandle.Init.CounterMode       = TIM_COUNTERMODE_UP;
    
40.   TimHandle.Init.RepetitionCounter = 0;
    
41.   if(HAL_TIM_IC_Init(&TimHandle) != HAL_OK)
    
42.   {
    
43.     /* Initialization Error */
    
44.     Error_Handler();
    
45.   }
    
46. 
    
47.   /*##-2- Configure the Input Capture channel ################################*/
    
48.   /* Configure the Input Capture of channel 2 */
    
49.   sICConfig.ICPolarity  = TIM_ICPOLARITY_RISING;
    
50.   sICConfig.ICSelection = TIM_ICSELECTION_DIRECTTI;
    
51.   sICConfig.ICPrescaler = TIM_ICPSC_DIV1;
    
52.   sICConfig.ICFilter    = 0;   
    
53.   if(HAL_TIM_IC_ConfigChannel(&TimHandle, &sICConfig, TIM_CHANNEL_2) != HAL_OK)
    
54.   {
    
55.     /* Configuration Error */
    
56.     Error_Handler();
    
57.   }
    
58.   
    
59.   /*##-3- Start the Input Capture in interrupt mode ##########################*/
    
60.   if(HAL_TIM_IC_Start_IT(&TimHandle, TIM_CHANNEL_2) != HAL_OK)
    
61.   {
    
62.     /* Starting Error */
    
63.     Error_Handler();
    
64.   }
    
65. 
    
66.   while (1)
    
67.   {
    
68.   }
    
69. }
    
70. 
    
71. /**
    
72.   * @brief  Conversion complete callback in non blocking mode
    
73.   * @param  htim : hadc handle
    
74.   * @retval None
    
75.   */
    
76. void HAL_TIM_IC_CaptureCallback(TIM_HandleTypeDef *htim)
    
77. {
    
78.   if (htim->Channel == HAL_TIM_ACTIVE_CHANNEL_2)
    
79.   {
    
80.     if(uhCaptureIndex == 0)
    
81.     {
    
82.       /* Get the 1st Input Capture value */
    
83.       uwIC2Value1 = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_2);
    
84.       uhCaptureIndex = 1;
    
85.     }
    
86.     else if(uhCaptureIndex == 1)
    
87.     {
    
88.       /* Get the 2nd Input Capture value */
    
89.       uwIC2Value2 = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_2);
    
90. 
    
91.       /* Capture computation */
    
92.       if (uwIC2Value2 > uwIC2Value1)
    
93.       {
    
94.         uwDiffCapture = (uwIC2Value2 - uwIC2Value1);
    
95.       }
    
96.       else if (uwIC2Value2 < uwIC2Value1)
    
97.       {
    
98.         /* 0xFFFF is max TIM1_CCRx value */
    
99.         uwDiffCapture = ((0xFFFF - uwIC2Value1) + uwIC2Value2) + 1;
    
100.       }
     
101.       else
     
102.       {
     
103.         /* If capture values are equal, we have reached the limit of frequency
     
104.            measures */
     
105.         Error_Handler();
     
106.       }
     
107.       /* Frequency computation: for this example TIMx (TIM1) is clocked by
     
108.          2*APB2Clk as APB2CLKDivider are set to RCC_APB2_DIV2 */      
     
109.       uwFrequency = 2*HAL_RCC_GetPCLK2Freq() / uwDiffCapture;
     
110.       uhCaptureIndex = 0;
     
111.     }
     
112.   }
     
113. }

复制代码

薪火相传

硬汉兄，这种官方的例子在哪里的？怎么在固件库里没看到

薪火相传

看到了

eric2013

薪火相传 发表于 2020-12-2 08:46
硬汉兄，这种官方的例子在哪里的？怎么在固件库里没看到

TIM_InputCapture