PWM输出实验灯的亮度没有变化，大神帮看代码啊啊啊！！！！

candykevin · 发表于 2017-6-18 14:43:21

最近在做一个项目，需要用到呼吸灯，复习了一遍视频之后写完程序。但是灯是一直亮着的，没有亮度的变化，按复位键也是这样。
下面是main函数代码：#include "stm32f10x.h"
#include "led.h"
#include "delay.h"
#include "timer.h"

int main(void)
{
u16 led0pwmval=0;
u8 dir=1;
delay_init();
timer_PWMinit(899,0);

while(1)
{
delay_ms(10);
   if(dir)led0pwmval++;
else led0pwmval--;

if(led0pwmval>300)dir=0;
if(led0pwmval==0)dir=1;
TIM_SetCompare1(TIM3,led0pwmval);
}

}

下面是timer.c的代码
#include "timer.h"
#include "delay.h"

void timer_PWMinit(u16 arr,u16 psc)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct;
GPIO_InitTypeDef GPIO_InitStructure;
TIM_OCInitTypeDef TIM_OCInitStruct;

//使能时钟
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE);

//配置GPIOA_6
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Pin=GPIO_Pin_6;
GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
GPIO_Init(GPIOA,&GPIO_InitStructure);

//配置timer3

TIM_TimeBaseInitStruct.TIM_ClockDivision=0;
TIM_TimeBaseInitStruct.TIM_CounterMode=TIM_CounterMode_Up;
TIM_TimeBaseInitStruct.TIM_Period=arr;
TIM_TimeBaseInitStruct.TIM_Prescaler=psc;
  TIM_TimeBaseInit(TIM3,&TIM_TimeBaseInitStruct);

  //配置ch1输出pwm
TIM_OCInitStruct.TIM_OCMode=TIM_OCMode_PWM2;
  TIM_OCInitStruct.TIM_OutputState=TIM_OutputState_Enable;
TIM_OCInitStruct.TIM_OCPolarity=TIM_OCPolarity_High;
TIM_OC1Init(TIM3,&TIM_OCInitStruct);

TIM_OC1PreloadConfig(TIM3,TIM_OCPreload_Enable);

TIM_Cmd(TIM3,ENABLE);

}

下面是我使用的芯片的管脚说明（PA6的复用功能为TIMER3_CH1）