STM32F407ZG PWM

//only for TIM1 and TIM8 仅高级定时器用

//TIM_OCInitStructure.TIM_OCIdleState = ; //TIM 互补输出比较状态

//TIM_OCInitStructure.TIM_OCNIdleState = ; //Idle 状态下 TIM 输出比较引脚状态

//TIM_OCInitStructure.TIM_OCNPolarity = ; //指定互补输出极性

//TIM_OCInitStructure.TIM_OutputNState = ; //Idle 状态下 TIM 输出比较引脚状态

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //TIM 输出比较模式

TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; //输出极性低

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

//TIM_OCInitStructure.TIM_Pulse = ; //捕获/比较寄存器 CCR 的值

TIM_OC1Init(TIM14, &TIM_OCInitStructure);

void TIM14_PWM_Init(uint32_t arr, uint32_t psc)

{

    GPIO_InitTypeDef GPIO_InitStructure;

    TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;

    TIM_OCInitTypeDef TIM_OCInitStructure;

    

    //使能时钟

    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOF, ENABLE);

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM14, ENABLE);

    

    GPIO_PinAFConfig(GPIOF, GPIO_PinSource9, GPIO_AF_TIM14); //复用

    

    //GPIOF初始化

    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;

    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;

    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;

    GPIO_Init(GPIOF, &GPIO_InitStructure);

    

    TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;

    TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;

    TIM_TimeBaseInitStructure.TIM_Period = arr;

    TIM_TimeBaseInitStructure.TIM_Prescaler = psc;

    //TIM_TimeBaseInitStructure.TIM_RepetitionCounter = ; only TIM1 TIM8

    TIM_TimeBaseInit(TIM14, &TIM_TimeBaseInitStructure);

    

    //only for TIM1 and TIM8 仅高级定时器用

    //TIM_OCInitStructure.TIM_OCIdleState = ; //TIM互补输出比较状态

    //TIM_OCInitStructure.TIM_OCNIdleState = ; //Idle状态下TIM输出比较引脚状态

    //TIM_OCInitStructure.TIM_OCNPolarity = ; //指定互补输出极性

    //TIM_OCInitStructure.TIM_OutputNState = ; //Idle状态下TIM输出比较引脚状态

    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //TIM输出比较模式

    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; //输出极性低

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

    //TIM_OCInitStructure.TIM_Pulse = ; //捕获/比较寄存器CCR的值，此程序在后面设置以控制LED的亮度

    TIM_OC1Init(TIM14, &TIM_OCInitStructure);

    

    TIM_OC1PreloadConfig(TIM14, TIM_OCPreload_Enable); //使能预装载寄存器

    TIM_ARRPreloadConfig(TIM14,ENABLE); //ARPE使能

    

    TIM_Cmd(TIM14, ENABLE); //使能TIM14

}

int main()

{

    uint8_t led_dir = 1; //调整增/减，1为递增，0为递减

    uint32_t led_crr = 0;

    

    delay_init(168);

    LED_init();

    TIM14_PWM_Init(500 - 1, 84 - 1); //定时器时钟为 84M ，分频系数为 84 ，所以计数频率

                                     //为 84M/84=1Mhz, 重装载值 500 ，所以 PWM 频率为 1M/500=2Khz.

    

    while(1)

    {

        delay_ms(10);

        if(led_dir)

        {

            led_crr++;

        }

        else {

            led_crr--;

        }

        if(led_crr > 30)

        {

            led_dir = 0;

        }

        if(led_crr == 0)

        {

            led_dir = 1;

        }

        TIM_SetCompare1(TIM14, led_crr); //修改比较值，即修改占空比

    }

}