stm32 定时器3产生指定数量的脉冲

一、场景描述：利用PB5产生一定数量的脉冲信号。PB5是定时器3的第2通道。

二、产生PWM代码：

void Timer3_Configuration(void )

{ 

TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;

TIM_OCInitTypeDef  TIM_OCInitStructure;

TIM_DeInit(TIM3);

// ƵÂÊ30K

//Õ¼¿Õ±È50%

 // TIM_TimeBaseStructure.TIM_Period = 100-1; 

//TIM_TimeBaseStructure.TIM_Prescaler =24-1;

// ƵÂÊ20K

//Õ¼¿Õ±È50%

// TIM_TimeBaseStructure.TIM_Period = 100-1; 

//TIM_TimeBaseStructure.TIM_Prescaler =36-1;

// ƵÂÊ10K

//Õ¼¿Õ±È50%

// TIM_TimeBaseStructure.TIM_Period = 100-1; 

// TIM_TimeBaseStructure.TIM_Prescaler =72-1;

// ƵÂÊK

//Õ¼¿Õ±È50%

TIM_TimeBaseStructure.TIM_Period = 300-1; 

TIM_TimeBaseStructure.TIM_Prescaler =72-1;

// ƵÂÊ1K

//Õ¼¿Õ±È10%

//TIM_TimeBaseStructure.TIM_Period = 1000-1; 

//TIM_TimeBaseStructure.TIM_Prescaler =72-1;

TIM_TimeBaseStructure.TIM_ClockDivision = 0;

//ʱÖÓ·ÖƵ

TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

//TIMÏòÉϼÆÊý

TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

TIM_ClearFlag(TIM3,TIM_FLAG_Update);         

TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE); 

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;

//PWM1λÕý³£Õ¼¿Õ±Èģʽ£¬pwm2Ϊ·´¼«ÐÔģʽ

TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;

//ʹÄÜÊä³ö

TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;

//»¥²¹Êä³ö¹¦ÄܽûÖ¹

TIM_OCInitStructure.TIM_Pulse = 30;

//Õ¼¿Õʱ¼ä

TIM_OC2Init(TIM3,&TIM_OCInitStructure);        //ͨµÀ2

TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);

// TIM_CtrlPWMOutputs(TIM3,ENABLE);

TIM_ARRPreloadConfig(TIM3, ENABLE);

//ʹÄÜTIMxÔÚARRPÉϵÄԤװÔؼĴæÆ÷

//TIM_Cmd(TIM3, ENABLE);

TIM_Cmd(TIM3, DISABLE);

//ʹÄÜTIM3

}

三、引脚初始化

可以看出来，PB5复用功能是I2C的功能，需要进行重映射。

        GPIO_InitStructure .GPIO_Pin=GPIO_Pin_8 ;

GPIO_InitStructure .GPIO_Speed =GPIO_Speed_10MHz;

GPIO_InitStructure .GPIO_Mode =GPIO_Mode_Out_PP ;//

GPIO_Init (GPIOB ,&GPIO_InitStructure );

GPIO_ResetBits(GPIOB,GPIO_Pin_8);

GPIO_PinRemapConfig(GPIO_PartialRemap_TIM3, ENABLE);

四、脉冲计数

void TIM3_IRQHandler(void)

{

if(TIM_GetITStatus (TIM3 ,TIM_IT_Update )!=RESET )

{

MD_Pulse_Cnt++;

}

TIM_ClearITPendingBit(TIM3 ,TIM_IT_Update );

}

void main()

{

    if(MD_Pulse_Cnt>500)

    TIM_Cmd(TIM3,DISABLE);

}

五、总体思路。

在定时器初始化中打开中断，然后在中断里进行脉冲计数。