stm32 pwm捕获学习笔记

前段时间抄袭其他的stm多通道捕获代码，调试没有通过，由于半路出家也不是读得太懂，后来发现官方有个例子，原来固件库里面自带PWM输入功能，经调试稳定可用，代码如下：

//计时器和gpio口的初始化
GPIO_InitTypeDef GPIO_InitStructure;
  NVIC_InitTypeDef NVIC_InitStructure;

  /* TIM2 clock enable */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

  /* GPIOB clock enable */
  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
  
  /* TIM2 chennel2 configuration : PA.01 */
  GPIO_InitStructure.GPIO_Pin   = GPIO_Pin_1;
  GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_UP ;
  GPIO_Init(GPIOA, &GPIO_InitStructure);
  
  /* Connect TIM pin to AF1 */
  GPIO_PinAFConfig(GPIOA, GPIO_PinSource1, GPIO_AF_1);

  /* Enable the TIM2 global Interrupt */
  NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
	
	TIM_ICInitStructure.TIM_Channel = TIM_Channel_2;
  TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
  TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
  TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
  TIM_ICInitStructure.TIM_ICFilter = 0x0;

  TIM_PWMIConfig(TIM2, &TIM_ICInitStructure);

  /* Select the TIM2 Input Trigger: TI2FP2 */
  TIM_SelectInputTrigger(TIM2, TIM_TS_TI2FP2);

  /* Select the slave Mode: Reset Mode */
  TIM_SelectSlaveMode(TIM2, TIM_SlaveMode_Reset);
  TIM_SelectMasterSlaveMode(TIM2,TIM_MasterSlaveMode_Enable);

  /* TIM enable counter */
  TIM_Cmd(TIM2, ENABLE);

  /* Enable the CC2 Interrupt Request */
   TIM_ITConfig(TIM2, TIM_IT_CC2, ENABLE);

 相关中断函数如下：

void TIM2_IRQHandler(void)
{
  RCC_GetClocksFreq(&RCC_Clocks);

  /* Clear TIM2 Capture compare interrupt pending bit */
  TIM_ClearITPendingBit(TIM2, TIM_IT_CC2);

  /* Get the Input Capture value */
  IC2Value = TIM_GetCapture2(TIM2);

  if (IC2Value != 0)
  {
    /* Duty cycle computation */
    DutyCycle = (TIM_GetCapture1(TIM2) * 100) / IC2Value;

    /* Frequency computation 
       TIM2 counter clock = (RCC_Clocks.HCLK_Frequency)/2 */

    Frequency = RCC_Clocks.HCLK_Frequency / IC2Value;
  }
  else
  {
    DutyCycle = 0;
    Frequency = 0;
  }
}

 这个方法经测试，是简单好用的，但根据资料表明这个是通道1和通道2配合实现，其他资料也没有说明如何捕获多个通道，是否能用3和4通道配合捕获，是否1个定时器能捕获2个通道。于是网上查到另一种方法可以1个定时器捕获4个通道（），但是待测试，记录如下：

// STM32 TIM2 4 Channel Input Capture STM32F0-Discovery - [email protected]
 
#include "stm32f0xx.h"
#include "stm32f0_discovery.h"
 
//**************************************************************************************
 
void TIM2_Config(void)
{
  TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
  TIM_ICInitTypeDef        TIM_ICInitStructure;
 
  /* TIM2 Periph clock enable */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
 
  /* TIM2 Configuration */
  TIM_DeInit(TIM2);
 
  /* Time base configuration */
  TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
  TIM_TimeBaseStructure.TIM_Prescaler = (SystemCoreClock / 1000000) - 1; // 1 MHz, from 48 MHz
  TIM_TimeBaseStructure.TIM_Period = 0xFFFFFFFF; // Maximal, TIM2 is 32-bit counter
  TIM_TimeBaseStructure.TIM_ClockDivision = 0x0;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
 
  TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; // Rising/Falling/BothEdge
  TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
  TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
  TIM_ICInitStructure.TIM_ICFilter = 0x0;
 
  TIM_ICInitStructure.TIM_Channel = TIM_Channel_1;
  TIM_ICInit(TIM2, &TIM_ICInitStructure);
  TIM_ICInitStructure.TIM_Channel = TIM_Channel_2;
  TIM_ICInit(TIM2, &TIM_ICInitStructure);
  TIM_ICInitStructure.TIM_Channel = TIM_Channel_3;
  TIM_ICInit(TIM2, &TIM_ICInitStructure);
  TIM_ICInitStructure.TIM_Channel = TIM_Channel_4;
  TIM_ICInit(TIM2, &TIM_ICInitStructure);
 
  /* TIM1 enable counter */
  TIM_Cmd(TIM2, ENABLE);
 
  /* Enable the CCx Interrupt Request */
  TIM_ITConfig(TIM2, TIM_IT_CC1 | TIM_IT_CC2 | TIM_IT_CC3 | TIM_IT_CC4, ENABLE);
}
 
//**************************************************************************************
 
volatile uint32_t Freq[4];
 
void TIM2_IRQHandler(void)
{
    uint32_t Current, Delta;
    static uint32_t Last[4];
     
  if (TIM_GetITStatus(TIM2, TIM_IT_CC1) != RESET)
    {
        /* Clear TIM2_CH1 Capture compare interrupt pending bit */
        TIM_ClearITPendingBit(TIM2, TIM_IT_CC1);
 
        Current = TIM_GetCapture1(TIM2);
        Delta = Current - Last[0];
        Last[0] = Current;
        if (Delta)
            Freq[0] = 1000000 / Delta; // 1MHz clock
         
        // ..
    }
     
  if (TIM_GetITStatus(TIM2, TIM_IT_CC2) != RESET)
    {
        /* Clear TIM2_CH2 Capture compare interrupt pending bit */
        TIM_ClearITPendingBit(TIM2, TIM_IT_CC2);
 
        Current = TIM_GetCapture2(TIM2);
        Delta = Current - Last[1];
        Last[1] = Current;
        if (Delta)
            Freq[1] = 1000000 / Delta; // 1MHz clock
         
        // ..
    }
     
  if (TIM_GetITStatus(TIM2, TIM_IT_CC3) != RESET)
    {
        /* Clear TIM2_CH3 Capture compare interrupt pending bit */
        TIM_ClearITPendingBit(TIM2, TIM_IT_CC3);
 
        Current = TIM_GetCapture3(TIM2);
        Delta = Current - Last[2];
        Last[2] = Current;
        if (Delta)
            Freq[2] = 1000000 / Delta; // 1MHz clock
         
        // ..
    }
     
  if (TIM_GetITStatus(TIM2, TIM_IT_CC4) != RESET)
    {
        /* Clear TIM2_CH4 Capture compare interrupt pending bit */
        TIM_ClearITPendingBit(TIM2, TIM_IT_CC4);
 
        Current = TIM_GetCapture4(TIM2);
        Delta = Current - Last[3];
        Last[3] = Current;
        if (Delta)
            Freq[3] = 1000000 / Delta; // 1MHz clock
         
        // ..
    }
}
 
//**************************************************************************************
 
void NVIC_Config(void)
{
  NVIC_InitTypeDef NVIC_InitStructure;
 
  /* Enable and set TIM2 Interrupt */
  NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPriority = 0x00;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
}
 
//**************************************************************************************
 
void GPIO_Config(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;
 
  /* GPIOA Periph clock enable */
  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
 
  /* Configure TIM2 input */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;
  GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
  GPIO_Init(GPIOA, &GPIO_InitStructure);
 
  /* Connect TIM pins to AF2 */
  GPIO_PinAFConfig(GPIOA, GPIO_PinSource5, GPIO_AF_2); // TIM2_CH1 PA5
  GPIO_PinAFConfig(GPIOA, GPIO_PinSource1, GPIO_AF_2); // TIM2_CH2 PA1
  GPIO_PinAFConfig(GPIOA, GPIO_PinSource2, GPIO_AF_2); // TIM2_CH3 PA2
  GPIO_PinAFConfig(GPIOA, GPIO_PinSource3, GPIO_AF_2); // TIM2_CH4 PA3
}
 
//**************************************************************************************
 
int main(void)
{
  NVIC_Config();
 
  GPIO_Config();
 
  TIM2_Config();
 
  while(1); /* Infinite loop */
}

 还有另外一种方法待测试：

// Hold onto the Channel 1 init structure -- we will use it to reverse
// polarity on every edge interrupt.
static TIM_ICInitTypeDef TIM_CH1_ICInitStructure;

#define GPIO_AF_TIM2 GPIO_AF_2

void ConfigPwmIn() {
 GPIO_InitTypeDef GPIO_InitStructure;
 TIM_ICInitTypeDef TIM_ICInitStructure;
 NVIC_InitTypeDef NVIC_InitStructure;

 TIM_DeInit(TIM2 );

 /* TIM2 clock enable */
 RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

 /* GPIOC clock enable */
 RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOD, ENABLE);

 /* TIM2 GPIO pin configuration : CH1=PD3, C2=PD4, CH3=PD7, CH4=PD6 */
 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3 | GPIO_Pin_4 | GPIO_Pin_7 | GPIO_Pin_6;
 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
 GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
 GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
 GPIO_Init(GPIOD, &GPIO_InitStructure);

 /* Connect pins to TIM3 AF2 */
 GPIO_PinAFConfig(GPIOD, GPIO_PinSource3, GPIO_AF_TIM2 );
 GPIO_PinAFConfig(GPIOD, GPIO_PinSource4, GPIO_AF_TIM2 );
 GPIO_PinAFConfig(GPIOD, GPIO_PinSource7, GPIO_AF_TIM2 );
 GPIO_PinAFConfig(GPIOD, GPIO_PinSource6, GPIO_AF_TIM2 );

 NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
 NVIC_Init(&NVIC_InitStructure);

 /* Enable capture*/
 TIM_CH1_ICInitStructure.TIM_Channel = TIM_Channel_1;
 TIM_CH1_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
 TIM_CH1_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
 TIM_CH1_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
 TIM_CH1_ICInitStructure.TIM_ICFilter = 0;
 TIM_ICInit(TIM2, &TIM_ICInitStructure);
 TIM_ICInitStructure.TIM_Channel = TIM_Channel_2;
 TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Falling;
 TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
 TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
 TIM_ICInitStructure.TIM_ICFilter = 0;
 TIM_ICInit(TIM2, &TIM_ICInitStructure);
 TIM_ICInitStructure.TIM_Channel = TIM_Channel_3;
 TIM_ICInit(TIM2, &TIM_ICInitStructure);
 TIM_ICInitStructure.TIM_Channel = TIM_Channel_4;
 TIM_ICInit(TIM2, &TIM_ICInitStructure);

 /* Enable TIM2 */
 TIM_Cmd(TIM2, ENABLE);

 /* Enable CC1-4 interrupt */
 TIM_ITConfig(TIM2, TIM_IT_CC1 | TIM_IT_CC2 | TIM_IT_CC3 | TIM_IT_CC4, ENABLE);

 /* Clear CC1 Flag*/
 TIM_ClearFlag(TIM2, TIM_FLAG_CC1 | TIM_FLAG_CC2 | TIM_FLAG_CC3 | TIM_FLAG_CC4 );
}

static volatile uint32_t ccr[4];
static volatile char pulseState = 0;

void TIM2_IRQHandler() {
 if (TIM2 ->SR & TIM_IT_CC1 ) {
  TIM2 ->SR &= (~TIM_IT_CC1 );

  if (pulseState == 0) {
   TIM_CH1_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Falling;

   // Any time we get a rising edge on CH1, we reset the counter. All channels are
   // phase aligned, so they all use this as a reference.
   TIM_SetCounter(TIM2, 0);
  } else {
   TIM_CH1_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;

   // Pull the value on the falling edge.
   ccr[0] = TIM_GetCapture1(TIM2 );
  }
  pulseState = !pulseState;

  // Reverse polarity.
  TIM_ICInit(TIM2, &TIM_CH1_ICInitStructure);
 }

 if (TIM2 ->SR & TIM_IT_CC2 ) {
  TIM2 ->SR &= (~TIM_IT_CC2 );
  ccr[1] = TIM_GetCapture2(TIM2 );
 }
 if (TIM2 ->SR & TIM_IT_CC3 ) {
  TIM2 ->SR &= (~TIM_IT_CC3 );
  ccr[2] = TIM_GetCapture3(TIM2 );
 }
 if (TIM2 ->SR & TIM_IT_CC4 ) {
  TIM2 ->SR &= (~TIM_IT_CC4 );
  ccr[3] = TIM_GetCapture4(TIM2 );
 }
}