拜托香主能不能给个STM32的pwm捕获的例程？

只看该作者 · 2009-10-29 12:14

拜托香主能不能给个STM32的pwm捕获的例程？我整了很久了就是测不出来

1万 · 2009-10-29 12:19

STM32固件库中有PWM输入模式的例子。

只看该作者 · 2009-10-29 12:55

不好意思，没有找到:'(

1万 · 2009-10-29 13:27

没有找到固件库？还是没有找到例子？

只看该作者 · 2009-10-29 13:29

没找到例子

只看该作者 · 2009-10-29 13:35

下面是我的程序，我要测量输入PWM的频率是50Hz,你看看有什么问题吗？
void tim2_config(void)
{
TIM_DeInit(TIM2);

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);
TIM_BaseInitStructure.TIM_Period = 65535;    //ARR
TIM_BaseInitStructure.TIM_Prescaler = 199;    //PSC
TIM_BaseInitStructure.TIM_ClockDivision = 0;
TIM_BaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_BaseInitStructure);

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);

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

TIM_SelectSlaveMode(TIM2, TIM_SlaveMode_Reset);                      //复位模式为从模式

TIM_SelectMasterSlaveMode(TIM2, TIM_MasterSlaveMode_Enable);       //使能主从模式

TIM_Cmd(TIM2, ENABLE);                         //使能TIM2计数器

TIM_ITConfig(TIM2, TIM_IT_CC2, ENABLE);       //使能CC2中断请求

}

void TIM2_IRQHandler(void)
{
  /* Clear TIM2 Capture compare interrupt pending bit */
  TIM_ClearITPendingBit(TIM2, TIM_IT_CC2);

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

/*******************************************************************************
* Function Name : NVIC_Configuration
* Description       : Configures NVIC and Vector Table base location.
* Input                   : None
* Output                : None
* Return                : None
*******************************************************************************/
void NVIC_Configuration(void)
{
  // NVIC_InitTypeDef NVIC_InitStructure;

#ifdef VECT_TAB_RAM
/* Set the Vector Table base location at 0x20000000 */
NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0);
#else /* VECT_TAB_FLASH */
/* Set the Vector Table base location at 0x08000000 */
NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0);
#endif

/* Configure the NVIC Preemption Priority Bits */
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);

/* Enable the USART1 Interrupt */
NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQChannel;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}

只看该作者 · 2009-10-29 14:50

int main(void)
{
#ifdef DEBUG
  debug();
#endif

  /* System Clocks Configuration */
  RCC_Configuration();

  /* NVIC configuration */
  NVIC_Configuration();

  /* Configure the GPIO ports */
  GPIO_Configuration();

  /* TIM2 configuration: PWM Input 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
   The TIM2 CCR1 is used to compute the duty cycle value
  ------------------------------------------------------------ */

  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);

  /* Enable the Master/Slave Mode */
  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);

  while (1);
}

这个是官方例子上的，没有进行Base的初始化

下面是中断处理函数
void TIM2_IRQHandler(void)
{
  /* 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 */
Frequency = 72000000 / IC2Value;
  }
  else
  {
DutyCycle = 0;
Frequency = 0;
  }
}