STM32F407 TIM1的PWM输出

//TIM1 PWM部分初始化 

//PWM输出初始化

//arr：自动重装值

//psc：时钟预分频数

void TIM1_PWM_Init(u32 arr,u32 psc)

{  

//此部分需手动修改IO口设置

GPIO_InitTypeDef GPIO_InitStructure;

TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;

TIM_OCInitTypeDef  TIM_OCInitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1,ENABLE);   //TIM1时钟使能    

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE); //使能PORTA时钟

//复用不能写成下面,会出问题

//GPIO_PinAFConfig(GPIOA,GPIO_PinSource8|GPIO_PinSource11,GPIO_AF_TIM1); //GPIO复用为定时器1

GPIO_PinAFConfig(GPIOA, GPIO_PinSource8, GPIO_AF_TIM1); //复用GPIOA_Pin8为TIM1_Ch1, 

GPIO_PinAFConfig(GPIOA, GPIO_PinSource11, GPIO_AF_TIM1);//复用GPIOA_Pin11为TIM1_Ch4,注意没有CH4N 

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8|GPIO_Pin_11;           //GPIO

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;        //复用功能

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz; //速度100MHz

GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;      //推挽复用输出

GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;        //上拉

GPIO_Init(GPIOA,&GPIO_InitStructure);              //初始化P

TIM_TimeBaseStructure.TIM_Prescaler=psc;  //定时器分频

TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式

TIM_TimeBaseStructure.TIM_Period=arr;   //自动重装载值

TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1; 

//TIM_TimeBaseStructure.TIM_RepetitionCounter = 0x0;//默认就为0

TIM_TimeBaseInit(TIM1,&TIM_TimeBaseStructure);//初始化定时器1

//初始化TIM1  PWM模式  

//PWM 模式 1–– 在递增计数模式下，只要 TIMx_CNT

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //PWM1为正常占空比模式，PWM2为反极性模式

  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能

TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; //输出极性:TIM输出比较极性低,有效电平为低电平

TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset;//在空闲时输出     低,这里的设置可以改变TIM_OCPolarity 如果没这句，第1通道有问题

TIM_OCInitStructure.TIM_Pulse = 2000; //输入通道1 CCR1（占空比数值）

TIM_OC1Init(TIM1, &TIM_OCInitStructure); //Ch1初始化

TIM_OCInitStructure.TIM_Pulse = 5000;

TIM_OC4Init(TIM1, &TIM_OCInitStructure);//通道4

TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);  //使能TIM1在CCR1上的预装载寄存器,CCR自动装载默认也是打开的

TIM_ARRPreloadConfig(TIM1,ENABLE);//ARPE使能 

TIM_Cmd(TIM1, ENABLE);  //使能TIM1

TIM_CtrlPWMOutputs(TIM1, ENABLE);//使能TIM1的PWM输出，TIM1与TIM8有效,如果没有这行会问题

}