GPIO_InitTypeDef GPIO_InitStructure2;         

 TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;        

 TIM_OCInitTypeDef TIM_OCInitStructure;        

 TIM_BDTRInitTypeDef TIM_BDTRInitStructure;

 //第一步：配置时钟                 

 RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_GPIOB|RCC_APB2Periph_TIM1,ENABLE);

 //第二步，配置goio口          

    GPIO_InitStructure2.GPIO_Pin=GPIO_Pin_8;         

 GPIO_InitStructure2.GPIO_Speed=GPIO_Speed_50MHz;         

 GPIO_InitStructure2.GPIO_Mode=GPIO_Mode_AF_PP;                 //设置为复用浮空输出         

 GPIO_Init(GPIOA,&GPIO_InitStructure2);        

 GPIO_InitStructure2.GPIO_Pin=GPIO_Pin_13;         

 GPIO_InitStructure2.GPIO_Speed=GPIO_Speed_50MHz;         

 GPIO_InitStructure2.GPIO_Mode=GPIO_Mode_AF_PP;                 //设置为复用浮空输出         

 GPIO_Init(GPIOB,&GPIO_InitStructure2);

 //第三步，定时器基本配置         

 TIM_TimeBaseStructure.TIM_Period=1000-1;                   // 自动重装载寄存器的值        

 TIM_TimeBaseStructure.TIM_Prescaler=72-1;                  // 时钟预分频数        

 TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1;      // 采样分频        

 TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up;  //向上计数        

 TIM_TimeBaseStructure.TIM_RepetitionCounter=0;      //重复寄存器，用于自动更新pwm占空比                       

 TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);

 //第四步pwm输出配置         

 TIM_OCInitStructure.TIM_OCMode=TIM_OCMode_PWM2;                    //设置为pwm1输出模式         

 TIM_OCInitStructure.TIM_Pulse=500;                                 //设置占空比时间         

 TIM_OCInitStructure.TIM_OCPolarity=TIM_OCPolarity_Low;             //设置输出极性         

 TIM_OCInitStructure.TIM_OutputState=TIM_OutputState_Enable;        //使能该通道输出         

 //下面几个参数是高级定时器才会用到，通用定时器不用配置         

 TIM_OCInitStructure.TIM_OCNPolarity=TIM_OCNPolarity_High;        //设置互补端输出极性         

 TIM_OCInitStructure.TIM_OutputNState=TIM_OutputNState_Enable;//使能互补端输出         

 TIM_OCInitStructure.TIM_OCIdleState=TIM_OCIdleState_Reset;        //死区后输出状态         

 TIM_OCInitStructure.TIM_OCNIdleState=TIM_OCNIdleState_Reset;//死区后互补端输出状态         

 TIM_OC1Init(TIM1,&TIM_OCInitStructure);                                            //按照指定参数初始化           

 //第五步，死区和刹车功能配置，高级定时器才有的，通用定时器不用配置         

 TIM_BDTRInitStructure.TIM_OSSRState = TIM_OSSRState_Disable;//运行模式下输出

 TIM_BDTRInitStructure.TIM_OSSIState = TIM_OSSIState_Disable;//空闲模式下输出选择          

 TIM_BDTRInitStructure.TIM_LOCKLevel = TIM_LOCKLevel_OFF;         //锁定设置        

 TIM_BDTRInitStructure.TIM_DeadTime = 0x90;                                         //死区时间设置         

 TIM_BDTRInitStructure.TIM_Break = TIM_Break_Disable;                 //刹车功能使能         

 TIM_BDTRInitStructure.TIM_BreakPolarity = TIM_BreakPolarity_High;//刹车输入极性        

 TIM_BDTRInitStructure.TIM_AutomaticOutput = TIM_AutomaticOutput_Enable;//自动输出使能         

 TIM_BDTRConfig(TIM1,&TIM_BDTRInitStructure);

 //第六步，使能端的打开 

 TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);  //使能TIMx在CCR1上的预装载寄存器         

 TIM_ARRPreloadConfig(TIM1, ENABLE);                //使能TIMx在ARR上的预装载寄存器         

 TIM_Cmd(TIM1,ENABLE);                              //打开TIM2         

 //下面这句是高级定时器才有的，输出pwm必须打开         

 TIM_CtrlPWMOutputs(TIM1, ENABLE);                                   //pwm输出使能，一定要记得打开

 // 在运行当中想要改变pwm的频率和占空比调用：

 TIM_SetAutoreload(TIM1,1000); 

 TIM_SetCompare1(TIM1,500);