利用PB9产生PWM信号

一、引脚初始化

        GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;

GPIO_Init(GPIOB, &GPIO_InitStructure);

二、定时器初始化

void TIM4_Config(void)

{ 

 // GPIO_InitTypeDef GPIO_InitStructure;

TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;

TIM_OCInitTypeDef  TIM_OCInitStructure;

TIM_DeInit(TIM4);

// 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;

// ƵÂÊ1K

TIM_TimeBaseStructure.TIM_Period = 1000-1; 

TIM_TimeBaseStructure.TIM_Prescaler =72-1;

TIM_TimeBaseStructure.TIM_ClockDivision = 0;

TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;

TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;

TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;

//TIM_OCInitStructure.TIM_Pulse = 100;

TIM_OCInitStructure.TIM_Pulse = Optical_Source_Duty;

//

// TIM_OC3Init(TIM4, &TIM_OCInitStructure);

// TIM_OC3PreloadConfig(TIM4, TIM_OCPreload_Enable);

TIM_OC4Init(TIM4, &TIM_OCInitStructure);

TIM_OC4PreloadConfig(TIM4, TIM_OCPreload_Enable);

TIM_CtrlPWMOutputs(TIM4,ENABLE);

TIM_ARRPreloadConfig(TIM4, ENABLE);

TIM_Cmd(TIM4, ENABLE);

}