/*******************TIM1定义***************************?void Timer_Configuration(void) {   TIM_TimeBaseInitTypeDef   TIM_TimeBaseStructure;   TIM_ICInitTypeDef     TIM_ICInitStructure; 
  //TIM1时基设定--捕获填充频率   TIM_DeInit(TIM1); 
  TIM_TimeBaseStructure.TIM_Period=0xFFFF;  //ARR的值   TIM_TimeBaseStructure.TIM_Prescaler=0;   TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1; //采样不分频,频率72M   TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式  // TIM_TimeBaseStructure.TIM_RepetitionCounter=TIM_EncoderMode_TI2;  TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);   TIM_PrescalerConfig(TIM1,0,TIM_PSCReloadMode_Immediate);//时钟分频系数0,系统时钟72MHZ   TIM_ARRPreloadConfig(TIM1, ENABLE);   //使能ARR预装载缓冲器    //定时器1捕获设置    TIM_ICInitStructure.TIM_Channel=TIM_Channel_1;   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=0;    TIM_ICInit(TIM1,&TIM_ICInitStructure);   //清中断，以免一启用中断后立即产生中断    TIM_ClearFlag(TIM1, TIM_IT_Update);//  TIM_FLAG_Update//使能TIM1溢出中断源    TIM_ITConfig(TIM1, TIM_IT_Update, ENABLE);  //TIM_ITConfig(TIM1, TIM_FLAG_CC1OF, ENABLE);  TIM_ITConfig(TIM1, TIM_IT_CC1, ENABLE);//使能捕获中断   TIM_GenerateEvent(TIM1,TIM_EventSource_Update);  TIM_Cmd(TIM1, ENABLE);  //使能定时器1 } 



void NVIC_Configuration(void) {   NVIC_InitTypeDef NVIC_InitStructure; 
  /* Enable the TIM2 global Interrupt */   NVIC_InitStructure.NVIC_IRQChannel = TIM1_CC_IRQn;   NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;   NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;   NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;   NVIC_Init(&NVIC_InitStructure);     NVIC_InitStructure.NVIC_IRQChannel =  TIM1_UP_IRQn;   NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;   NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;   NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;   NVIC_Init(&NVIC_InitStructure);  } 


void GPIO_Configuration(void) {   GPIO_InitTypeDef GPIO_InitStructure;   GPIO_DeInit(GPIOA);  /* TIM2 channel 2 pin (PA.01) configuration */   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;     GPIO_Init(GPIOA, &GPIO_InitStructure); }
/****************定时器中断服务函数 *******************************///要想得到足够大的测频范围，只要定义相应的OV_count，cap_diff足够大就可以了 //建议freq_1array[]可以设置成double类型的变量，那样可以有小数频率！ void TIM1_CC_IRQHandler(void) {  //捕获处理 if(TIM_GetITStatus(TIM1,TIM_IT_CC1)!=RESET) {   TIM_ClearITPendingBit(TIM1,TIM_IT_CC1); if(1==cap_count) //捕获频率 { OV_count=0; old_cap=TIM_GetCapture1(TIM1);//TIM_GetCounter
} else if(cap_count>10)        //捕获十次{ new_cap=TIM_GetCapture1(TIM1);// TIM_GetCountercap_diff=new_cap-old_cap+65535*OV_count; freq_1array=720000000.0/cap_diff;//这里72000000*10是对10次捕获求平均值 *100是求小数后两位cap_count=1; OV_count=0; } cap_count++; } } 
//TIM1溢出中断服务子程序：TIM1_FLAG_CC1OF  void TIM1_UP_IRQHandler(void)  {  TIM_ClearITPendingBit(TIM1, TIM_IT_Update); //清中断  OV_count++;} 





void main(void)  {  /* config the sysclock to 72m */  SystemInit();  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_TIM1|                         RCC_APB2Periph_AFIO,ENABLE);   Timer_Configuration(); GPIO_Configuration(); NVIC_Configuration();  while(1);     }    
要把中断中的 freq_1array=720000000.0/cap_diff 改成360000000.0才正确为什么呢。。
/**************"stm32f10x.h"**********************************/#if defined (STM32F10X_LD_VL) || (defined STM32F10X_MD_VL) || (defined STM32F10X_HD_VL)/* #define SYSCLK_FREQ_HSE    HSE_VALUE */ #define SYSCLK_FREQ_24MHz  24000000#else/* #define SYSCLK_FREQ_HSE    HSE_VALUE *//* #define SYSCLK_FREQ_24MHz  24000000 */ /* #define SYSCLK_FREQ_36MHz  36000000 *//* #define SYSCLK_FREQ_48MHz  48000000 *//* #define SYSCLK_FREQ_56MHz  56000000 */#define SYSCLK_FREQ_72MHz  72000000#endif [ 本帖最后由 pk3725069 于 2012-3-14 18:06 编辑 ] 此帖出自小平头技术问答