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01 RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //時(shí)鐘配置 02 RCC_APP2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE); 03 04 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7; //GPIO配置 05 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; 06 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; 07 GPIO_Init(GPIOA, &GPIO_InitStructure); 08 09 NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn; //NVIC配置 10 NVIC_InitStructure.NVIC_IRQChannePreemptionPriority = 0; 11 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; 12 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; 13 NVIC_Init(&NVIC_InitStructure); 14 15 TIM_ICInitStructure.TIM_Channel = TIM_Channel_2; //通道選擇 16 TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; //上升沿觸發(fā) 17 TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //管腳與寄存器對(duì)應(yīng)關(guān)系 18 TIM_ICInitStructure.TIM_ICPSC_DIV1;//輸入預(yù)分頻，意思是控制在多少個(gè)輸入周期做一個(gè)捕獲，如果輸入的信號(hào)頻率沒(méi)有變，測(cè)得的周期也不會(huì)變，比如選擇四分頻，則沒(méi)四個(gè)輸入周期做一次捕獲，這昂再輸入信號(hào)不頻繁的情況下，可以減少軟件被不斷中斷的次數(shù) 19 20 TIM_ICInitStructure.TIM_ICFiter = 0x0; //濾波設(shè)置，經(jīng)歷幾個(gè)周期跳變認(rèn)定波形穩(wěn)定0x0-0xf; 21 TIM_PWMIConfig(TIM3, &TIM_ICInitStructure); //根據(jù)參數(shù)配置TIM外設(shè)信息 22 TIM_SelectInputTrigger(TIM3, TIM_TS_TI2FP2); 23 TIM_SelectMasterSalveMode(TIM3, TIM_MasterSlaveMode_Enable); 24 TIM_Cmd(TIM3, ENABLE); 25 TIM_ITConfig(TIM3, TIM_IT_CC2, ENABLE); 26 27 void TIM3_IRQHandler(void) 28 { 29 TIM_CLearITPendingBit(TIM3, TIM_IT_CC3); 30 IC2Value = TIM_GetCapture2(TIM3); 31 if(IC2Value != 0) 32 { 33 DutyCyle = (TIM_GetCapture1(TIM3) * 100) / IC2Value; 34 Frequency = 72000000 / IC2Value; 35 } 36 else 37 { 38 DutyCycle = 0; 39 Frequency = 0; 40 } 41 42 } 43 44 注（一）：若想改變測(cè)量的PWM頻率范圍，可將TIM時(shí)鐘頻率做分頻處理 45 46 TIM_TimeBaseStructure.TIM_Period = 0xFFFF; //周期0～FFFF 47 TIM_TimeBaseStructure.TIM_Prescaler = 5; //時(shí)鐘分頻，分頻數(shù)為5+1即6分頻 48 TIM_TimeBaseStructure.TIM_ClockDivision = 0; //時(shí)鐘分割 49 TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;//模式 50 TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);//基本初始化 51 注注（二）：定時(shí)器TIM的倍頻器X1或X2。在APB分頻為1時(shí)，倍頻值為1，否則為2 |
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來(lái)自： woshizmxin > 《root》
