這是上周我學輸入捕獲的時候寫的源代碼，超聲波測距，通過串口顯示。- void TIM3_CAP_Init(u16 arr,u16 psc)
- {
-
- GPIO_InitTypeDef GPIO_InitStructure;
- TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
- TIM_ICInitTypeDef TIM_ICInitStructure;
- NVIC_InitTypeDef NVIC_InitStructure;
-
- //使能相應時鐘
- RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE);
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);
-
- //GPIOA 0 初始化
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD; //輸入下拉
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
- GPIO_Init(GPIOA,&GPIO_InitStructure);
- GPIO_ResetBits(GPIOA,GPIO_Pin_0); //設置為低電平
-
- //初始化定時器
- TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1; //不分頻
- TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up; //向上計數
- TIM_TimeBaseInitStructure.TIM_Period = arr; //自動重裝載的值
- TIM_TimeBaseInitStructure.TIM_Prescaler = psc; //預分頻的系數
- TIM_TimeBaseInit(TIM3,&TIM_TimeBaseInitStructure);
-
- //初始化捕獲通道
- TIM_ICInitStructure.TIM_Channel = TIM_Channel_1; //通道1
- TIM_ICInitStructure.TIM_ICFilter = 0x00; //不使用慮波器
- TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; //設置為上升沿捕獲
- TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; //分頻不分頻
- TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //通道的映射關系
- TIM_ICInit(TIM3,&TIM_ICInitStructure);
-
- //初始化中斷
- NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn; //TIM3中斷
- NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
- NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
- NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
- NVIC_Init(&NVIC_InitStructure);
-
-
- //開啟捕獲和更新中斷
- TIM_ITConfig(TIM3,TIM_IT_Update | TIM_IT_CC1, ENABLE);
-
- //使能定時器
- TIM_Cmd(TIM3,ENABLE);
-
-
- }
- u8 TIM3CH1_CAPTURE_STA = 0;
- u16 TIM3CH1_CAPTURE_VAL = 0;
- //中斷服務函數
- void TIM3_IRQHandler(void)
- {
- if((TIM3CH1_CAPTURE_STA & 0x80) == 0) //如果還沒完成捕獲
- {
- if(TIM_GetITStatus(TIM3,TIM_IT_Update) != RESET) //更新中斷來了
- {
- if(TIM3CH1_CAPTURE_STA & 0x40) //如果上一次捕獲到高電平
- {
- if((TIM3CH1_CAPTURE_STA & 0x3f) == 0x3f) //如果定時器溢出次數記滿了
- {
- TIM3CH1_CAPTURE_STA |= 0x80; //記滿了強制捕獲完成
- TIM3CH1_CAPTURE_VAL = 0xffff; //記滿
- }
- else //否則
- {
- TIM3CH1_CAPTURE_STA ++; //每來一次更新中斷自加一次
- }
- }
- }
- if(TIM_GetITStatus(TIM3,TIM_IT_CC1) != RESET) //如果捕獲中斷來了
- {
- if(TIM3CH1_CAPTURE_STA & 0x40) //如果上次捕獲到高電平
- {
- TIM3CH1_CAPTURE_STA |= 0x80; //捕獲完成
- TIM3CH1_CAPTURE_VAL = TIM_GetCapture1(TIM3); //將通道的值給 VAL
- TIM_OC1PolarityConfig(TIM3,TIM_ICPolarity_Rising); //完成捕獲還要設置下降沿觸發
- }
- else //第一次捕獲
- {
- TIM3CH1_CAPTURE_STA = 0; //清零
- TIM3CH1_CAPTURE_VAL = 0;
- TIM_SetCounter(TIM3,0);
- TIM3CH1_CAPTURE_STA |= 0x40; //采集到高電平了
- TIM_OC1PolarityConfig(TIM3,TIM_ICPolarity_Falling); //設置下降沿觸發
- }
- }
- }
- TIM_ClearITPendingBit(TIM3,TIM_IT_Update | TIM_IT_CC1); //清除中斷標志位
- }
8.3 輸入捕獲（超聲波測距）.7z
(183.95 KB, 下載次數: 55)
2019-7-19 15:51 上傳
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