text: /**
    ******************************************************************************
    * @file    TIM/TIM_PWMInput/Src/main.c
    * @author  MCD Application Team
    * @brief   This example shows how to use the TIM peripheral to measure the
    *          frequency and duty cycle of an external signal.
    ******************************************************************************
    * @attention
    *
    * <h2><center>&copy; COPYRIGHT(c) 2017 STMicroelectronics</center></h2>
    *
    * Redistribution and use in source and binary forms, with or without modification,
    * are permitted provided that the following conditions are met:
    *   1. Redistributions of source code must retain the above copyright notice,
    *      this list of conditions and the following disclaimer.
    *   2. Redistributions in binary form must reproduce the above copyright notice,
    *      this list of conditions and the following disclaimer in the documentation
    *      and/or other materials provided with the distribution.
    *   3. Neither the name of STMicroelectronics nor the names of its contributors
    *      may be used to endorse or promote products derived from this software
    *      without specific prior written permission.
    *
    * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
    * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
    * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
    * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
    * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
    * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    *
    ******************************************************************************
    */
  
  /* Includes ------------------------------------------------------------------*/
  #include "main.h"
  
  /** @addtogroup STM32F4xx_HAL_Examples
    * @{
    */
  
  /** @addtogroup TIM_PWMInput
    * @{
    */
  
  /* Private typedef -----------------------------------------------------------*/
  /* Private define ------------------------------------------------------------*/
  /* Private macro -------------------------------------------------------------*/
  /* Private variables ---------------------------------------------------------*/
  /* Timer handler declaration */
  TIM_HandleTypeDef    TimHandle;
  
  /* Timer Input Capture Configuration Structure declaration */
  TIM_IC_InitTypeDef       sConfig;
  
  /* Slave configuration structure */
  TIM_SlaveConfigTypeDef   sSlaveConfig;
  
  /* Captured Value */
  __IO uint32_t            uwIC2Value = 0;
  /* Duty Cycle Value */
  __IO uint32_t            uwDutyCycle = 0;
  /* Frequency Value */
  __IO uint32_t            uwFrequency = 0;
  
  /* Private function prototypes -----------------------------------------------*/
  static void SystemClock_Config(void);
  static void Error_Handler(void);
  
  /* Private functions ---------------------------------------------------------*/
  
  /**
    * @brief  Main program.
    * @param  None
    * @retval None
    */
  int main(void)
  {
    /* STM32F4xx HAL library initialization:
         - Configure the Flash prefetch, instruction and Data caches
         - Systick timer is configured by default as source of time base, but user 
           can eventually implement his proper time base source (a general purpose 
           timer for example or other time source), keeping in mind that Time base 
           duration should be kept 1ms since PPP_TIMEOUT_VALUEs are defined and 
           handled in milliseconds basis.
         - Set NVIC Group Priority to 4
         - Low Level Initialization: global MSP (MCU Support Package) initialization
       */
    HAL_Init();
  
    /* Configure the system clock to 180 MHz */
    SystemClock_Config();
  
    /* Configure LED3 */
    BSP_LED_Init(LED3);
  
    /*##-1- Configure the TIM peripheral #######################################*/
    /* ---------------------------------------------------------------------------
    TIM1 configuration: PWM Input mode
  
    In this example TIM1 input clock (TIM1CLK) is set to APB2 clock x 2,
      since APB2 prescaler is 2.
      TIM1CLK = APB2CLK*2
      APB2CLK = HCLK/2
      => TIM1CLK = HCLK = SystemCoreClock 
  
    External Signal Frequency = TIM1 counter clock / TIM1_CCR2 in Hz.
  
    External Signal DutyCycle = (TIM1_CCR1*100)/(TIM1_CCR2) in %.
  
    --------------------------------------------------------------------------- */
  
    /* Set TIMx instance */
    TimHandle.Instance = TIMx;
  
    /* Initialize TIMx peripheral as follows:
         + Period = 0xFFFF
         + Prescaler = 0
         + ClockDivision = 0
         + Counter direction = Up
    */
    TimHandle.Init.Period            = 0xFFFF;
    TimHandle.Init.Prescaler         = 0;
    TimHandle.Init.ClockDivision     = 0;
    TimHandle.Init.CounterMode       = TIM_COUNTERMODE_UP;
    TimHandle.Init.RepetitionCounter = 0;
    TimHandle.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
    if (HAL_TIM_IC_Init(&TimHandle) != HAL_OK)
    {
      /* Initialization Error */
      Error_Handler();
    }
  
    /*##-2- Configure the Input Capture channels ###############################*/
    /* Common configuration */
    sConfig.ICPrescaler = TIM_ICPSC_DIV1;
    sConfig.ICFilter = 0;
  
    /* Configure the Input Capture of channel 1 */
    sConfig.ICPolarity = TIM_ICPOLARITY_FALLING;
    sConfig.ICSelection = TIM_ICSELECTION_INDIRECTTI;
    if (HAL_TIM_IC_ConfigChannel(&TimHandle, &sConfig, TIM_CHANNEL_1) != HAL_OK)
    {
      /* Configuration Error */
      Error_Handler();
    }
  
    /* Configure the Input Capture of channel 2 */
    sConfig.ICPolarity = TIM_ICPOLARITY_RISING;
    sConfig.ICSelection = TIM_ICSELECTION_DIRECTTI;
    if (HAL_TIM_IC_ConfigChannel(&TimHandle, &sConfig, TIM_CHANNEL_2) != HAL_OK)
    {
      /* Configuration Error */
      Error_Handler();
    }
    /*##-3- Configure the slave mode ###########################################*/
    /* Select the slave Mode: Reset Mode  */
    sSlaveConfig.SlaveMode        = TIM_SLAVEMODE_RESET;
    sSlaveConfig.InputTrigger     = TIM_TS_TI2FP2;
    sSlaveConfig.TriggerPolarity  = TIM_TRIGGERPOLARITY_NONINVERTED;
    sSlaveConfig.TriggerPrescaler = TIM_TRIGGERPRESCALER_DIV1;
    sSlaveConfig.TriggerFilter    = 0;
    if (HAL_TIM_SlaveConfigSynchronization(&TimHandle, &sSlaveConfig) != HAL_OK)
    {
      /* Configuration Error */
      Error_Handler();
    }
  
    /*##-4- Start the Input Capture in interrupt mode ##########################*/
    if (HAL_TIM_IC_Start_IT(&TimHandle, TIM_CHANNEL_2) != HAL_OK)
    {
      /* Starting Error */
      Error_Handler();
    }
  
    /*##-5- Start the Input Capture in interrupt mode ##########################*/
    if (HAL_TIM_IC_Start_IT(&TimHandle, TIM_CHANNEL_1) != HAL_OK)
    {
      /* Starting Error */
      Error_Handler();
    }
  
    while (1)
    {
    }
  }
  
  /**
    * @brief  Input Capture callback in non blocking mode 
    * @param  htim : TIM IC handle
    * @retval None
    */
  void HAL_TIM_IC_CaptureCallback(TIM_HandleTypeDef *htim)
  {
    if (htim->Channel == HAL_TIM_ACTIVE_CHANNEL_2)
    {
      /* Get the Input Capture value */
      uwIC2Value = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_2);
  
      if (uwIC2Value != 0)
      {
        /* Duty cycle computation */
        uwDutyCycle = ((HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_1)) * 100) / uwIC2Value;
  
        /* uwFrequency computation
        TIM1 counter clock = (RCC_Clocks.HCLK_Frequency) */
        uwFrequency = (HAL_RCC_GetHCLKFreq())  / uwIC2Value;
      }
      else
      {
        uwDutyCycle = 0;
        uwFrequency = 0;
      }
    }
  }
  
  /**
    * @brief  This function is executed in case of error occurrence.
    * @param  None
    * @retval None
    */
  static void Error_Handler(void)
  {
    /* Turn LED3 on */
    BSP_LED_On(LED3);
    while (1)
    {
    }
  }
  
  /**
    * @brief  System Clock Configuration
    *         The system Clock is configured as follow : 
    *            System Clock source            = PLL (HSE)
    *            SYSCLK(Hz)                     = 180000000
    *            HCLK(Hz)                       = 180000000
    *            AHB Prescaler                  = 1
    *            APB1 Prescaler                 = 4
    *            APB2 Prescaler                 = 2
    *            HSE Frequency(Hz)              = 25000000
    *            PLL_M                          = 25
    *            PLL_N                          = 360
    *            PLL_P                          = 2
    *            PLL_Q                          = 7
    *            PLL_R                          = 6
    *            VDD(V)                         = 3.3
    *            Main regulator output voltage  = Scale1 mode
    *            Flash Latency(WS)              = 5
    * @param  None
    * @retval None
    */
  static void SystemClock_Config(void)
  {
    RCC_ClkInitTypeDef RCC_ClkInitStruct;
    RCC_OscInitTypeDef RCC_OscInitStruct;
    HAL_StatusTypeDef ret = HAL_OK;
  
    /* Enable Power Control clock */
    __HAL_RCC_PWR_CLK_ENABLE();
  
    /* The voltage scaling allows optimizing the power consumption when the device is 
       clocked below the maximum system frequency, to update the voltage scaling value 
       regarding system frequency refer to product datasheet.  */
    __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
  
    /* Enable HSE Oscillator and activate PLL with HSE as source */
    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
    RCC_OscInitStruct.HSEState = RCC_HSE_ON;
    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
    RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
    RCC_OscInitStruct.PLL.PLLM = 25;
    RCC_OscInitStruct.PLL.PLLN = 360;
    RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
    RCC_OscInitStruct.PLL.PLLQ = 7;
    RCC_OscInitStruct.PLL.PLLR = 6;
    
    ret = HAL_RCC_OscConfig(&RCC_OscInitStruct);
    if(ret != HAL_OK)
    {
      while(1) { ; }
    }
    
    /* Activate the OverDrive to reach the 180 MHz Frequency */  
    ret = HAL_PWREx_EnableOverDrive();
    if(ret != HAL_OK)
    {
      while(1) { ; }
    }
    
    /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 clocks dividers */
    RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
    RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
    RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4;  
    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;  
    
    ret = HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5);
    if(ret != HAL_OK)
    {
      while(1) { ; }
    }
  }
  
  #ifdef  USE_FULL_ASSERT
  
  /**
    * @brief  Reports the name of the source file and the source line number
    *         where the assert_param error has occurred.
    * @param  file: pointer to the source file name
    * @param  line: assert_param error line source number
    * @retval None
    */
  void assert_failed(uint8_t *file, uint32_t line)
  {
    /* User can add his own implementation to report the file name and line number,
       ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  
    /* Infinite loop */
    while (1)
    {
    }
  }
  
  #endif
  
  /**
    * @}
    */
  
  /**
    * @}
    */
  
  /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
  