STM32 自定义频率与占空比PWM输出的方法

int main(void) //主函数

 {undefined

delay_init(); //延时函数初始化

uart_init(9600);  //串口初始化

TIM4_PWM_Init(999,7199); //TIM4 PWM输出初始化

TIM3_Interrupt_Init(999,7199); //TIM3定时器中断初始化



pwmval= 600; //占空比



 while(1) ；

}



void TIM4_PWM_Init(u16 arr,u16 psc) //TIM4 定时器PWM输出功能初始化函数

{  

GPIO_InitTypeDef GPIO_InitStructure;

TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;

TIM_OCInitTypeDef  TIM_OCInitStructure;





RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB  | RCC_APB2Periph_AFIO, ENABLE);//使能GPIO外设和AFIO复用功能模块时钟使能



GPIO_InitStructure.GPIO_Pin = /*GPIO_Pin_6 | GPIO_Pin_7|*/GPIO_Pin_8 | GPIO_Pin_9;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;   //复用推挽输出

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOB, &GPIO_InitStructure);





TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值 80K

TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值  不分频

TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim

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

TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位



TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //PWM模式2

TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //正向通道有效

TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable; //反向通道无效

TIM_OCInitStructure.TIM_Pulse = 0; //占空时间



// TIM_OC1Init(TIM4,&TIM_OCInitStructure);        //通道1

// TIM_OC1PreloadConfig(TIM4, TIM_OCPreload_Enable);

// TIM_OC2Init(TIM4,&TIM_OCInitStructure);        //通道2

// TIM_OC2PreloadConfig(TIM4, TIM_OCPreload_Enable);

TIM_OC3Init(TIM4, &TIM_OCInitStructure); //使能通道3

TIM_OC3PreloadConfig(TIM4, TIM_OCPreload_Enable);

TIM_OC4Init(TIM4, &TIM_OCInitStructure); //使能通道4

TIM_OC4PreloadConfig(TIM4, TIM_OCPreload_Enable);





TIM_CtrlPWMOutputs(TIM4,ENABLE);





TIM_ARRPreloadConfig(TIM4, ENABLE); //使能TIMx在ARR上的预装载寄存器

TIM_Cmd(TIM4, ENABLE); //使能TIMx外设

}



void TIM3_Interrupt_Init(u16 arr,u16 psc) //TIM3定时器中断功能初始化函数

{undefined

TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;

NVIC_InitTypeDef NVIC_InitStructure;





RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //时钟使能



TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值 计数到5000为500ms

TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值  10Khz的计数频率  

TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim

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

TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位



TIM_ITConfig(TIM3,TIM_IT_Update | TIM_IT_Trigger,ENABLE);





NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn; //TIM3中断

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; //抢占优先级0级

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; //相应优先级3级

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能

NVIC_Init(&NVIC_InitStructure); //根据NVIC_InitStruct中指定的参数初始化外设NVIC寄存器





TIM_Cmd(TIM3, ENABLE); //使能TIMx外设

}



void TIM3_IRQHandler(void) //TIM3中断服务函数

{

if(TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET) //检查指定的TIM中断发生与否:TIM 中断源 

{undefined

++Event;

if(Event == 1)

{undefined

TIM_SetCompare3(TIM4,(led0pwmval*80)/100);

}

if(Event == 2)

{undefined

Event = 0;



TIM_SetCompare3(TIM4,(led0pwmval*20)/100);

}





TIM_ClearITPendingBit(TIM3, TIM_IT_Update); //清除TIMx的中断待处理位:TIM 中断源 

}

}