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stm32做PWM实验,输出的不是方波,而是有点像梯子一样的波形,新人求解~~

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ranguangxu|  楼主 | 2013-3-1 09:33 | 只看该作者 回帖奖励 |倒序浏览 |阅读模式
#include "stm32f10x.h"
//#include "delay.h"

void TIM2_PWM_Init(void);

//u16 nTime;

int main(void)
{
        SystemInit();
       
        TIM2_PWM_Init();
        while(1)
        {       
        }
               
}

void TIM2_PWM_Init(void)
{

        GPIO_InitTypeDef        GPIO_InitStructure;
        TIM_TimeBaseInitTypeDef TIM_BaseInitStructure;
    TIM_OCInitTypeDef TIM_OCInitStructure;
        TIM_BDTRInitTypeDef TIM_BDTRInitStructure;

        RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB |RCC_APB2Periph_GPIOC | RCC_APB2Periph_GPIOD,ENABLE);
        RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
        RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);
/*
        GPIO_InitStructure.GPIO_Pin=GPIO_Pin_8| GPIO_Pin_9 |GPIO_Pin_10;
        GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP;
        GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
        GPIO_Init(GPIOA, &GPIO_InitStructure);
*/
        GPIO_InitStructure.GPIO_Pin=GPIO_Pin_10| GPIO_Pin_13| GPIO_Pin_14;
        GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP;
        GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
        GPIO_Init(GPIOB, &GPIO_InitStructure);

    //TIM1基本计数器设置(设置PWM频率)
    //频率=TIM1_CLK/(ARR+1)
    TIM_BaseInitStructure.TIM_Period = 1000-1;
    TIM_BaseInitStructure.TIM_Prescaler = 72-1;
    TIM_BaseInitStructure.TIM_ClockDivision = 0;
    TIM_BaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_BaseInitStructure.TIM_RepetitionCounter = 0;
    TIM_TimeBaseInit(TIM1, &TIM_BaseInitStructure);
    //启用ARR的影子寄存器(直到产生更新事件才更改设置)
    TIM_ARRPreloadConfig(TIM1, ENABLE);


    //TIM1_OC1模块设置(设置1通道占空比)
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;
    TIM_OCInitStructure.TIM_Pulse = 120;
    TIM_OC1Init(TIM1, &TIM_OCInitStructure);
    //启用CCR1寄存器的影子寄存器(直到产生更新事件才更改设置)
    TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);

    //TIM2_OC2模块设置(设置2通道占空比)
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
    TIM_OCInitStructure.TIM_Pulse = 500;
    TIM_OC2Init(TIM1, &TIM_OCInitStructure);
    //启用CCR2寄存器的影子寄存器(直到产生更新事件才更改设置)
    TIM_OC2PreloadConfig(TIM1, TIM_OCPreload_Enable);

    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
    TIM_OCInitStructure.TIM_Pulse = 200;
    TIM_OC3Init(TIM1, &TIM_OCInitStructure);
    //启用CCR3寄存器的影子寄存器(直到产生更新事件才更改设置)
    TIM_OC3PreloadConfig(TIM1, TIM_OCPreload_Enable);
          
    //死区设置
    TIM_BDTRInitStructure.TIM_OSSRState = TIM_OSSRState_Enable;
    TIM_BDTRInitStructure.TIM_OSSIState = TIM_OSSIState_Enable;
    TIM_BDTRInitStructure.TIM_LOCKLevel = TIM_LOCKLevel_OFF;
    TIM_BDTRInitStructure.TIM_DeadTime = 0x90;  //这里调整死区大小0-0xff
    TIM_BDTRInitStructure.TIM_Break = TIM_Break_Disable;
    TIM_BDTRInitStructure.TIM_BreakPolarity = TIM_BreakPolarity_High;
    TIM_BDTRInitStructure.TIM_AutomaticOutput = TIM_AutomaticOutput_Enable;
    TIM_BDTRConfig(TIM1, &TIM_BDTRInitStructure);
   
    //TIM1开启
    TIM_Cmd(TIM1, ENABLE);
    //TIM1_OC通道输出PWM(一定要加)
    TIM_CtrlPWMOutputs(TIM1, ENABLE);
}
沙发
jiaxinhui| | 2013-3-14 22:07 | 只看该作者
我也做PWM输出实验了, 有实验的波形图
具体请参考这个贴子:https://bbs.21ic.com/icview-405944-1-1.html

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