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/**
******************************************************************************
* @file TIM/TIM_InputCapture/Src/main.c
* @author MCD Application Team
* @brief This example shows how to use the TIM peripheral to measure only
* the frequency of an external signal.
******************************************************************************
* @attention
*
* Copyright (c) 2017 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
/* Includes ------------------------------------------------------------------*/
#include "main.h"
/** @addtogroup STM32F4xx_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 -----------------------------------------------*/
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
- 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 180 MHz */
SystemClock_Config();
/* Configure LED2 */
BSP_LED_Init(LED2);
/*##-1- Configure the TIM peripheral #######################################*/
/* TIM3 configuration: Input Capture mode ---------------------
The external signal is connected to TIM3 CH2 pin (PB.05)
The Rising edge is used as active edge,
The TIM3 CCR2 is used to compute the frequency value
* TIM3 input clock is set to APB1 clock (PCLK1),
* if (APB1 prescaler = 1) x1 else x2
* prescaler is 4.
* TIM3CLK = (HCLK/4) x2 = (HCLK/2)
------------------------------------------------------------ */
/* 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 TIM3_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 (TIM3) is clocked by
2xAPB1Clk */
uwFrequency = (2*HAL_RCC_GetPCLK1Freq()) / uwDiffCapture;
uhCaptureIndex = 0;
}
}
}
/**
* @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) = 8000000
* PLL_M = 8
* PLL_N = 360
* PLL_P = 2
* PLL_Q = 7
* PLL_R = 2
* 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_BYPASS;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLM = 8;
RCC_OscInitStruct.PLL.PLLN = 360;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
RCC_OscInitStruct.PLL.PLLQ = 7;
RCC_OscInitStruct.PLL.PLLR = 2;
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) { ; }
}
}
/**
* @brief This function is executed in case of error occurrence.
* @param None
* @retval None
*/
static void Error_Handler(void)
{
/* Turn LED2 on */
BSP_LED_On(LED2);
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
/**
* @}
*/
/**
* @}
*/