秀操作：用HC-SR04和STM32F103ZET6做超聲波測距

void TIM3_Int_Init(u16 arr,u16 psc){ TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; NVIC_InitTypeDef NVIC_InitStructure;  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //時鐘使能  TIM_TimeBaseStructure.TIM_Period = arr; //設(shè)置在下一個更新事件裝入活動的自動重裝載寄存器周期的值 計數(shù)到5000為500ms TIM_TimeBaseStructure.TIM_Prescaler =psc; //設(shè)置用來作為TIMx時鐘頻率除數(shù)的預(yù)分頻值 10Khz的計數(shù)頻率  TIM_TimeBaseStructure.TIM_ClockDivision = 0; //設(shè)置時鐘分割:TDTS = Tck_tim TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上計數(shù)模式 TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //根據(jù)TIM_TimeBaseInitStruct中指定的參數(shù)初始化TIMx的時間基數(shù)單位  TIM_ITConfig( //使能或者失能指定的TIM中斷 TIM3, //TIM2 TIM_IT_Update | //TIM 中斷源 TIM_IT_Trigger, //TIM 觸發(fā)中斷源 ENABLE //使能 ); NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn; //TIM3中斷 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; //先占優(yōu)先級0級 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //從優(yōu)先級3級 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能 NVIC_Init(&NVIC_InitStructure); //根據(jù)NVIC_InitStruct中指定的參數(shù)初始化外設(shè)NVIC寄存器  TIM_Cmd(TIM3, ENABLE); //使能TIMx外設(shè) } void TIM3_IRQHandler(void) //TIM3中斷{ if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET) //檢查指定的TIM中斷發(fā)生與否:TIM 中斷源 { TIM_ClearITPendingBit(TIM3, TIM_IT_Update ); //清除TIMx的中斷待處理位:TIM 中斷源 LED1=!LED1; }}    //PWM輸出初始化//arr：自動重裝值//psc：時鐘預(yù)分頻數(shù) void TIM3_PWM_Init(u16 arr,u16 psc){  GPIO_InitTypeDef GPIO_InitStructure; TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; TIM_OCInitTypeDef TIM_OCInitStructure;   RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE); //使能GPIO外設(shè)和AFIO復(fù)用功能模塊時鐘使能  GPIO_PinRemapConfig(GPIO_PartialRemap_TIM3, ENABLE); //Timer3部分重映射 TIM3_CH2->PB5 //用于TIM3的CH2輸出的PWM通過該LED顯示  //設(shè)置該引腳為復(fù)用輸出功能,輸出TIM3 CH2的PWM脈沖波形 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5; //TIM_CH2 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //復(fù)用推挽輸出 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOB, &GPIO_InitStructure); //GPIO_WriteBit(GPIOA, GPIO_Pin_7,Bit_SET); // PA7上拉   TIM_TimeBaseStructure.TIM_Period = arr; //設(shè)置在下一個更新事件裝入活動的自動重裝載寄存器周期的值 80K TIM_TimeBaseStructure.TIM_Prescaler =psc; //設(shè)置用來作為TIMx時鐘頻率除數(shù)的預(yù)分頻值 不分頻 TIM_TimeBaseStructure.TIM_ClockDivision = 0; //設(shè)置時鐘分割:TDTS = Tck_tim TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上計數(shù)模式 TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //根據(jù)TIM_TimeBaseInitStruct中指定的參數(shù)初始化TIMx的時間基數(shù)單位   TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //選擇定時器模式:TIM脈沖寬度調(diào)制模式2 TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比較輸出使能 TIM_OCInitStructure.TIM_Pulse = 0; //設(shè)置待裝入捕獲比較寄存器的脈沖值 TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //輸出極性:TIM輸出比較極性高 TIM_OC2Init(TIM3, &TIM_OCInitStructure); //根據(jù)TIM_OCInitStruct中指定的參數(shù)初始化外設(shè)TIMx TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable); //使能TIMx在CCR2上的預(yù)裝載寄存器  TIM_ARRPreloadConfig(TIM3, ENABLE); //使能TIMx在ARR上的預(yù)裝載寄存器   TIM_Cmd(TIM3, ENABLE); //使能TIMx外設(shè)  } //定時器5通道1輸入捕獲配置 TIM_ICInitTypeDef TIM5_ICInitStructure; void TIM5_Cap_Init(u16 arr,u16 psc){  GPIO_InitTypeDef GPIO_InitStructure; TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; NVIC_InitTypeDef NVIC_InitStructure;  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM5, ENABLE); //使能TIM5時鐘 RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE); //使能GPIOA時鐘  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; //PA0 清除之前設(shè)置  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD; //PA0 輸入  GPIO_Init(GPIOA, &GPIO_InitStructure); GPIO_ResetBits(GPIOA,GPIO_Pin_0); //PA0 下拉  //初始化定時器5 TIM5  TIM_TimeBaseStructure.TIM_Period = arr; //設(shè)定計數(shù)器自動重裝值 TIM_TimeBaseStructure.TIM_Prescaler =psc; //預(yù)分頻器  TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; //設(shè)置時鐘分割:TDTS = Tck_tim TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上計數(shù)模式 TIM_TimeBaseInit(TIM5, &TIM_TimeBaseStructure); //根據(jù)TIM_TimeBaseInitStruct中指定的參數(shù)初始化TIMx的時間基數(shù)單位  //初始化TIM5輸入捕獲參數(shù) TIM5_ICInitStructure.TIM_Channel = TIM_Channel_1; //CC1S=01 選擇輸入端 IC1映射到TI1上 TIM5_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; //上升沿捕獲 TIM5_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //映射到TI1上 TIM5_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; //配置輸入分頻,不分頻 TIM5_ICInitStructure.TIM_ICFilter = 0x00;//IC1F=0000 配置輸入濾波器 不濾波 TIM_ICInit(TIM5, &TIM5_ICInitStructure);  //中斷分組初始化 NVIC_InitStructure.NVIC_IRQChannel = TIM5_IRQn; //TIM3中斷 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2; //先占優(yōu)先級2級 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //從優(yōu)先級0級 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能 NVIC_Init(&NVIC_InitStructure); //根據(jù)NVIC_InitStruct中指定的參數(shù)初始化外設(shè)NVIC寄存器  TIM_ITConfig(TIM5,TIM_IT_Update|TIM_IT_CC1,ENABLE);//允許更新中斷 ,允許CC1IE捕獲中斷   TIM_Cmd(TIM5,ENABLE ); //使能定時器5} u8 TIM5CH1_CAPTURE_STA=0; //輸入捕獲狀態(tài) u16 TIM5CH1_CAPTURE_VAL; //輸入捕獲值 //定時器5中斷服務(wù)程序 void TIM5_IRQHandler(void){  if((TIM5CH1_CAPTURE_STA&0X80)==0)//還未成功捕獲  {  if (TIM_GetITStatus(TIM5, TIM_IT_Update) != RESET)  {  if(TIM5CH1_CAPTURE_STA&0X40)//已經(jīng)捕獲到高電平了 { if((TIM5CH1_CAPTURE_STA&0X3F)==0X3F)//高電平太長了 { TIM5CH1_CAPTURE_STA|=0X80;//標(biāo)記成功捕獲了一次 TIM5CH1_CAPTURE_VAL=0XFFFF; }else TIM5CH1_CAPTURE_STA++; }  } if (TIM_GetITStatus(TIM5, TIM_IT_CC1) != RESET)//捕獲1發(fā)生捕獲事件 {  if(TIM5CH1_CAPTURE_STA&0X40) //捕獲到一個下降沿  {  TIM5CH1_CAPTURE_STA|=0X80; //標(biāo)記成功捕獲到一次高電平脈寬 TIM5CH1_CAPTURE_VAL=TIM_GetCapture1(TIM5); TIM_OC1PolarityConfig(TIM5,TIM_ICPolarity_Rising); //CC1P=0 設(shè)置為上升沿捕獲 }else //還未開始,第一次捕獲上升沿 { TIM5CH1_CAPTURE_STA=0; //清空 TIM5CH1_CAPTURE_VAL=0; TIM_SetCounter(TIM5,0); TIM5CH1_CAPTURE_STA|=0X40; //標(biāo)記捕獲到了上升沿 TIM_OC1PolarityConfig(TIM5,TIM_ICPolarity_Falling); //CC1P=1 設(shè)置為下降沿捕獲 }  }  }  TIM_ClearITPendingBit(TIM5, TIM_IT_CC1|TIM_IT_Update); //清除中斷標(biāo)志位 }