定时器输出PWM波

#include "stm32f10x.h"

int main(void)

{

// SystemInit();

//配置IO口

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOD | RCC_APB2Periph_GPIOE,ENABLE);//IO口使能设置

GPIO_InitTypeDef GPIO_InitStructure; //定义结构体

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8; //TIM3的CH3连接PB8管脚

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);

//定时器2

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4,ENABLE);//配置时钟

TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

TIM_TimeBaseStructure.TIM_Period=10000; //1s

TIM_TimeBaseStructure.TIM_Prescaler=7199; //720分频

TIM_TimeBaseStructure.TIM_ClockDivision=0;

TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up;//向上计数

TIM_TimeBaseInit(TIM4,&TIM_TimeBaseStructure);

TIM_OCInitTypeDef TIM_OCInitStructure;

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;//PWM1模式1

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

TIM_OCInitStructure.TIM_Pulse = 2500; //设置占空比

TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //输出比较极性高

TIM_OC3Init(TIM4, & TIM_OCInitStructure); //初始化TIM4的CH3通道

TIM_OC3PreloadConfig(TIM4, TIM_OCPreload_Enable); //使能TIM4在CH3通道CCR3上的预装载寄存器

TIM_ARRPreloadConfig(TIM4, ENABLE);//使能TIM4在CH3通道ARR3上的预装载寄存器

TIM_Cmd(TIM4,ENABLE);//使能定时器4

while(1);

}

//以下是报错函数

#ifdef USE_FULL_ASSERT

void assert_failed(uint8_t* file, uint32_t line)

{

while (1)

{

}

}

#endif