[应用相关] STM32之PWM波形输出配置总结

GPIO_InitTypeDef GPIO_InitStructure;//定义结构体

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

GPIO_PinRemapConfig(GPIO_PartialRemap_TIM3, ENABLE); //选择Timer3部分重映像    

//选择定时器3的通道2作为PWM的输出引脚TIM3_CH2->PB5    GPIOB.5

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5; //TIM_CH2

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  //复用推挽功能

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOB, &GPIO_InitStructure);//初始化引脚

TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;//定义初始化结构体

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //使能定时器3时钟

//初始化TIM3

TIM_TimeBaseStructure.TIM_Period = arr; //自动重装载寄存器的值

TIM_TimeBaseStructure.TIM_Prescaler =psc; //TIMX预分频的值

TIM_TimeBaseStructure.TIM_ClockDivision = 0; //时钟分割

TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //向上计数

TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //根据以上功能对定时器进行初始化

TIM_OCInitTypeDef  TIM_OCInitStructure;//定义结构体

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;//选择定时器模式，TIM脉冲宽度调制模式2

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

TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;//输出比较极性低

TIM_OC2Init(TIM3, &TIM_OCInitStructure);//根据结构体信息进行初始化

TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);  //使能定时器TIM2在CCR2上的预装载值

int main(void)

{

　　TIM3_PWM_Init(9999,143);//频率为：72*10^6/(9999+1)/(143+1)=50Hz

　　TIM_SetCompare2(TIM3,4999);//得到占空比为50%的pwm波形

　　while(1);

}