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参考一下这个#include "timer.h"//TIM2 PWM部分初始化//PWM输出初始化//arr:自动重装值//psc:时钟预分频数void TIM2_PWM_Init(u16 arr,u16 psc){GPIO_InitTypeDef GPIO_InitStructure;TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;TIM_OCInitTypeDef TIM_OCInitStructure;RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE); //使能定时器2时钟RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE); //使能GPIO外设和AFIO复用功能模块时钟GPIO_PinRemapConfig(GPIO_PartialRemap2_TIM2, ENABLE); //Timer3部分重映射 TIM2_CH2->PA1//设置该引脚为复用输出功能,输出TIM2 CH2的PWM脉冲波形 GPIOA.1GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1; //TIM_CH2GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //复用推挽输出GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA, &GPIO_InitStructure);//初始化GPIOA//初始化TIM2TIM_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TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_timTIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上计数模式TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位//初始化TIM2 Channel2 PWM模式TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //选择定时器模式:TIM脉冲宽度调制模式2TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能TIM_OCInitStructure.TIM_Pulse = 0; //设置待装入捕获比较寄存器的脉冲值TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //输出极性:TIM输出比较极性高TIM_OC2Init(TIM2, &TIM_OCInitStructure); //根据T指定的参数初始化外设TIM2 OC2TIM_OC2PreloadConfig(TIM2, TIM_OCPreload_Enable); //使能TIM2在CCR2上的预装载寄存器TIM_ARRPreloadConfig(TIM2, ENABLE); //使能TIMx在ARR上的预装载寄存器TIM_Cmd(TIM2, ENABLE); //使能TIM2}#ifndef __TIMER_H#define __TIMER_H#include "sys.h"void TIM2_PWM_Init(u16 arr,u16 psc);#endif#include "delay.h"#include "timer.h"/*舵机控制周期限制在20ms,脉宽部分为0.5ms--2.5ms0.5ms对应0度1ms对应45度1.5ms对应90度2ms对应135度2.5ms对应180度*/int main(void){u16 pwmval=0;delay_init(); //延时函数初始化TIM2_PWM_Init(1999,719); //不分频PWM频率=100000/2000=50hzwhile(1){pwmval=1850;TIM_SetCompare2(TIM2,pwmval);}}