STM32 general timer input capture mode

#include "stm32f10x.h"

/*RCC clock configuration*/

void RCC_config()

{ 

 ErrorStatus HSEStartUpStatus;

 /* RCC registers are set to default configuration */

 RCC_DeInit();

 /* Turn on external high speed clock */

 RCC_HSEConfig(RCC_HSE_ON);

 /* Wait for the external high-speed clock to stabilize*/

 HSEStartUpStatus = RCC_WaitForHSEStartUp();

 if(HSEStartUpStatus == SUCCESS) 

 { 

  /* Set HCLK = SYSCLK */

  RCC_HCLKConfig(RCC_SYSCLK_Div1);

  /* Set PCLK2 = HCLK */

  RCC_PCLK2Config(RCC_HCLK_Div1);

  /* Set PCLK1 = HCLK / 2 */

  RCC_PCLK1Config(RCC_HCLK_Div2);

// /* Set FLASH code delay */

//  FLASH_SetLatency(FLASH_Latency_2);

// /* Enable prefetch cache */

//  FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);

  /* Set the PLL clock source to HSE multiplier 9 72MHz */

  RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_9);

  /* Enable PLL */

  RCC_PLLCmd(ENABLE);

  /* Wait for PLL to stabilize */

  while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET);

  /* Set PLL as system clock source */

  RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);

  /* Wait for the system clock source to switch to PLL */

  while(RCC_GetSYSCLKSource() != 0x08);

 }

}

/* GPIO configuration */

void GPIO_config()

{

 GPIO_InitTypeDef GPIO_InitStructure;

 /* Enable GPIOA clock */

 RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOC | RCC_APB2Periph_AFIO, ENABLE);

 /* Set the GPIOA clock to default parameters */

 GPIO_DeInit(GPIOA); 

 /* Pull-down output */

 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD;

 /* Pin 13 */

 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;

 /* Output frequency 50MHz */

 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

 /* Initialize GPIOA_0 */

 GPIO_Init(GPIOA, &GPIO_InitStructure);

}

/* Timer configuration */

void TIMER_config()

{

 TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

 TIM_ICInitTypeDef TIM_ICInitStructure;

 /* Enable TIM2 clock */

 RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

 /* Set the Timer 2 register to initial value */

 TIM_DeInit(TIM2);

 /* Set timer 2 to use internal clock */

 TIM_InternalClockConfig(TIM2);

 /* Prescaler value*/

 TIM_TimeBaseStructure.TIM_Prescaler = 72 - 1;

 /* Clock division */

 TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;

 /* count up */

 TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

 /* Automatic reload value*/

 TIM_TimeBaseStructure.TIM_Period = 1000 - 1;

 /* Initialize timer 2 */

 TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

 /* Channel 1 */

 TIM_ICInitStructure.TIM_Channel = TIM_Channel_1;

 /* rising edge trigger */

 TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;

 /* Map to TI1 */

 TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;

 /* Frequency division*/

 TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;

 /* Filter */

 TIM_ICInitStructure.TIM_ICFilter = 0x00;

 /* Initialize input capture */

 TIM_ICInit(TIM2, &TIM_ICInitStructure);

 /* Clear interrupt flag */

 TIM_ClearFlag(TIM2, TIM_IT_Update | TIM_IT_CC1);

 /* Enable TIM2 interrupt */

 TIM_ITConfig(TIM2, TIM_IT_Update | TIM_IT_CC1, ENABLE);

 /* Start timer 2 */

 TIM_Cmd(TIM2, ENABLE);

}

/* Abort placement */

void NVIC_config()

{

 NVIC_InitTypeDef NVIC_InitStructure;

 /* Select interrupt group 1 */

 NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);

 /* Select the interrupt channel of TIM2 */

 NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;

 /* Set the preemptive interrupt priority to 0 */

 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;

 /* Set the responsive interrupt priority to 0 */

 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;

 /* Enable interrupt */

 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

 /* Interrupt initialization */

 NVIC_Init(&NVIC_InitStructure);

}

/* Delay in milliseconds */

void delay_ms(uint16_t time)

{    

 uint16_t i = 0;

 while(time--)

 {

  i = 12000;

  while(i--);

 }

}

/* Timer 2 interrupt vector */

void TIM2_IRQHandler(void)

{

 static uint32_t capture = 0;

 /* Input capture interrupt */

 if(TIM_GetITStatus(TIM2, TIM_IT_CC1) != RESET)    

 {

  /* Clear interrupt flag */

  capture += TIM_GetCapture1(TIM2);

  /* Clear the counter value */

  TIM_SetCounter(TIM2, 0);

  capture = 0;

 }

 /* Update interrupt */

 if(TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET)

 {

  capture += 1000;

 }  

 TIM_ClearFlag(TIM2, TIM_IT_CC1 | TIM_IT_Update);

 TIM_ClearITPendingBit(TIM2, TIM_IT_CC1 | TIM_IT_Update);

}

int main()

{

 /* Clock configuration */

 RCC_config();

 /* GPIO configuration */

 GPIO_config();

 /* Interrupt placement*/

 NVIC_config();

 /* Timer 2 configuration */

 TIMER_config();

 while(1)

 {

  delay_ms(1000);

 }

}