定時器當計數(shù)器使用對外部脈沖計數(shù)

1、STM32定時器做外部脈沖信號計數(shù)器用標簽：定時器 計數(shù)器 2012-09-17 11:31今天，嘗試使用 STM32的計數(shù)器的外部時鐘功能，來對外部脈沖信號進行計數(shù)。效果還 不錯。具體設置如下：/* TIM3_CH2為脈沖輸入口1. 配置 GPIO_GPIOA_PIN7 輸入2. 配置TIM3計數(shù)器在TI2端的上升沿計數(shù)1) . TIMx_CCMR1: CC2S =01;2) . TIMx_CCMR1:IC2F =000;3) . TIMx_CCER: CC2P =0;4) . TIMx_SMCR: SMS =111;5) . TIMx_SMCR: TS =110;6) . TIMx_CR1

2、: CEN =1;*/配置通道2檢測TI2輸入的上升沿選擇輸入濾波器帶寬配置上升沿極性V選擇定時器外部時鐘模式1選擇TI2作為觸發(fā)輸入源V啟動計數(shù)器void TIM3_External_Clock_Cou ntin gMode(void)GPIO_I ni tTypeDef GPIO_I nitStructure;TIM_TimeBaseI ni tTypeDef TIM_TimeBaseStructure;/ TIMCln itTypeDef TIMClni tStructure;RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);GPI

3、O_I ni tStructure.GPIO_Pin = GPIO_Pin_7;GPIO_I ni tStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;GPIO_I nitStructure.GPIO_Speed = GPIO_Speed_50MH z;GPIO_Init(GPIOA, &GPIO_InitStructure);RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);TIM_DeI ni t(TIM3);TIM_TimeBaseStructure.TIM_Period = 0xFFFF

4、;TIM_TimeBaseStructure.TIM_Prescaler = 0x00;TIM_TimeBaseStructure.TIM_ClockDivision = 0x0; /*定時器時鐘(CK_INT) 頻率與數(shù)字濾波器(ETR,TIx)使用的采樣頻率之間的分頻比為1*/TIM_TimeBaseStructure.TIM_Cou nterMode = TIM_Cou nterMode_Up;TIM_TimeBaseI nit( TIM3, &TIM_TimeBaseStructure); / Time base configur/*tmpccmrl |= (ui nt16_t

5、)(TIMCFilter << 12);/ CCMR1_IC2Ftmpccmrl |= (ui nt16_t)(TIMCSelection << 8); / CCMR1_CC2S 由 TIM_TlxExternalCLK1Source_TI2決定了TIMCSelecti on=TIMCSelection_DirectTI:CCMR1_CC2S = 01;TIMCPolarity_Risi ng= CCER_CC2PTIM_TIxExternalCLK1Source_TI2 = TIM_SMCR_TS該函數(shù)定義了 TIM_SlaveMode_External1; 外部時鐘

6、模式1*/TIM_TlxExternalClockCo nfig(TIM3,TIM_TlxExternalCLK1Source_TI2,TIMCPo larity_Risi ng,0);/ TIM_SetCounter(TIM3, 0); /清零計數(shù)器 CNT/ TIM_Cmd(TIM3,ENABLE);/下面是使用方法：TIM3_External_Clock_Cou ntin gMode();TIM_SetCounter(TIM3, 0); /清零計數(shù)器 CNTTIM_Cmd(TIM3,ENABLE);SecC nt = 0;TFgs.Secok = 0;i=0;while(1)Delay_Nms(1000);Cou ntPulse = TIM_GetCou nter(TIM3);DisplayDat(10,10+24*i,Cou ntPulse,5);TFgs.Secok = 0;if(+Cou ntTims>=120)TIM_Cmd(TIM3,DISABLE);Cou ntPulse = TIM_GetCou nter(TIM3);DisplayDat(10,10+24*i,Cou ntPulse,5);if(+i>11)i=0;T