/**
  ******************************************************************************
  * @file    TIM/TIM_InputCapture/Src/main.c
  * @author  MCD Application Team
  * @version V1.5.0
  * @date    14-April-2017
  * @brief   This example shows how to use the TIM peripheral to measure only 
  *          the frequency  of an external signal.
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; COPYRIGHT(c) 2016 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 STM32F1xx_HAL_Examples
  * @{
  */

/** @addtogroup TIM_InputCapture
  * @{
  */

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Timer handler declaration */
TIM_HandleTypeDef    TimHandle;

/* Timer Input Capture Configuration Structure declaration */
TIM_IC_InitTypeDef     sICConfig;

/* Captured Values */
uint32_t               uwIC2Value1 = 0;
uint32_t               uwIC2Value2 = 0;
uint32_t               uwDiffCapture = 0;

/* Capture index */
uint16_t               uhCaptureIndex = 0;

/* Frequency Value */
uint32_t               uwFrequency = 0;


/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void Error_Handler(void);

/* Private functions ---------------------------------------------------------*/

/**
  * @brief  Main program
  * @param  None
  * @retval None
  */
int main(void)
{
  /* STM32F103xG HAL library initialization:
       - Configure the Flash prefetch
       - 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
     */
  HAL_Init();

  /* Configure the system clock to 72 MHz */
  SystemClock_Config();

  /* Configure LED3 */
  BSP_LED_Init(LED3);

  /*##-1- Configure the TIM peripheral #######################################*/
  /* TIM2 configuration: Input Capture mode ---------------------
     The external signal is connected to TIM2 CH2 pin (PA.01)  
     The Rising edge is used as active edge,
     The TIM2 CCR2 is used to compute the frequency value 
  ------------------------------------------------------------ */

  /* 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 channel ################################*/ 
  /* Configure the Input Capture of channel 2 */
  sICConfig.ICPolarity  = TIM_ICPOLARITY_RISING;
  sICConfig.ICSelection = TIM_ICSELECTION_DIRECTTI;
  sICConfig.ICPrescaler = TIM_ICPSC_DIV1;
  sICConfig.ICFilter    = 0;   
  if(HAL_TIM_IC_ConfigChannel(&TimHandle, &sICConfig, TIM_CHANNEL_2) != HAL_OK)
  {
    /* Configuration Error */
    Error_Handler();
  }
  
  /*##-3- Start the Input Capture in interrupt mode ##########################*/
  if(HAL_TIM_IC_Start_IT(&TimHandle, TIM_CHANNEL_2) != HAL_OK)
  {
    /* Starting Error */
    Error_Handler();
  }

  while (1)
  {
  }
}

/**
  * @brief  Conversion complete callback in non blocking mode 
  * @param  htim : hadc handle
  * @retval None
  */
void HAL_TIM_IC_CaptureCallback(TIM_HandleTypeDef *htim)
{
  if (htim->Channel == HAL_TIM_ACTIVE_CHANNEL_2)
  {
    if(uhCaptureIndex == 0)
    {
      /* Get the 1st Input Capture value */
      uwIC2Value1 = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_2);
      uhCaptureIndex = 1;
    }
    else if(uhCaptureIndex == 1)
    {
      /* Get the 2nd Input Capture value */
      uwIC2Value2 = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_2); 

      /* Capture computation */
      if (uwIC2Value2 > uwIC2Value1)
      {
        uwDiffCapture = (uwIC2Value2 - uwIC2Value1); 
      }
      else if (uwIC2Value2 < uwIC2Value1)
      {
        /* 0xFFFF is max TIM2_CCRx value */
        uwDiffCapture = ((0xFFFF - uwIC2Value1) + uwIC2Value2) + 1;
      }
      else
      {
        /* If capture values are equal, we have reached the limit of frequency
           measures */
        Error_Handler();
      }
      /* Frequency computation: for this example TIMx (TIM2) is clocked by
         APB1Clk */      
      uwFrequency = HAL_RCC_GetPCLK1Freq() / uwDiffCapture;
      uhCaptureIndex = 0;
    }
  }
}

/**
  * @brief  System Clock Configuration
  *         The system Clock is configured as follow : 
  *            System Clock source            = PLL (HSE)
  *            SYSCLK(Hz)                     = 72000000
  *            HCLK(Hz)                       = 72000000
  *            AHB Prescaler                  = 1
  *            APB1 Prescaler                 = 2
  *            APB2 Prescaler                 = 1
  *            HSE Frequency(Hz)              = 8000000
  *            HSE PREDIV1                    = 1
  *            PLLMUL                         = 9
  *            Flash Latency(WS)              = 2
  * @param  None
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_ClkInitTypeDef clkinitstruct = {0};
  RCC_OscInitTypeDef oscinitstruct = {0};
  
  /* Enable HSE Oscillator and activate PLL with HSE as source */
  oscinitstruct.OscillatorType  = RCC_OSCILLATORTYPE_HSE;
  oscinitstruct.HSEState        = RCC_HSE_ON;
  oscinitstruct.HSEPredivValue  = RCC_HSE_PREDIV_DIV1;
  oscinitstruct.PLL.PLLState    = RCC_PLL_ON;
  oscinitstruct.PLL.PLLSource   = RCC_PLLSOURCE_HSE;
  oscinitstruct.PLL.PLLMUL      = RCC_PLL_MUL9;
  if (HAL_RCC_OscConfig(&oscinitstruct)!= HAL_OK)
  {
    /* Initialization Error */
    while(1);
  }

  /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 
     clocks dividers */
  clkinitstruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
  clkinitstruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  clkinitstruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  clkinitstruct.APB2CLKDivider = RCC_HCLK_DIV1;
  clkinitstruct.APB1CLKDivider = RCC_HCLK_DIV2;  
  if (HAL_RCC_ClockConfig(&clkinitstruct, FLASH_LATENCY_2)!= HAL_OK)
  {
    /* Initialization Error */
    while(1);
  }
}


/**
  * @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)
  {
  }
}
#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****/
