关于SPWM波的波形问题

枉不觉 · 发表于 2018-6-10 10:42:32

#include "led.h"
#include "delay.h"
#include "key.h"
#include "sys.h"
#include "usart.h"
#include "timer.h"
#include "math.h"

#define SIN_NUM 127

int main(void)
{
u16 led0pwmval=0;
u8 dir=1;
u8 i;
u16 Sin_Data[128]={450,472,494,516,537,559,580,601,622,642,662,681,700,718,735,752,
                  768,783,797,811,824,835,846,856,865,873,880,886,891,895,897,899,
                  900,899,897,895,891,886,880,873,865,856,846,835,824,811,797,783,
                  768,752,735,718,700,681,662,642,622,601,580,559,537,516,494,472,
                  450,427,405,383,362,340,319,298,277,257,237,218,199,181,164,147,
                  131,116,102,88,75,64,53,43,34,26,19,13,8,4,2,0,
                  0,0,2,4,8,13,19,26,34,43,53,64,75,88,102,116,
                  131,147,164,181,199,218,237,257,277,298,319,340,362,383,405,427};

delay_init();
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
uart_init(115200);
LED_Init();
TIM3_PWM_Init(899,7200);
   while(1)
{
if(TIM3->SR && 0x02==0x02)  //判断CC1IF标志位是否置1
{
TIM3->CCR2=Sin_Data[i];
i++;
if(i>=SIN_NUM) i=0;
TIM3->SR=TIM3->SR&(~0x02); //CC1IF软件清零
}
}
}
各位大佬这是我的main.c部分程序，我想通过不断判断CC1IF的状态来给我的CCR2赋值，以此来改变占空比，但是我用示波器看，我的波形占空比基本上没怎么变，请大佬们赐教。

以下是关于定时器配置的部分
TIM_TimeBaseStructure.TIM_Period = arr;
TIM_TimeBaseStructure.TIM_Prescaler =psc;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_CenterAligned1;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC2Init(TIM3, &TIM_OCInitStructure);

TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
// TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStructure.TIM_Pulse=1;  //CCR1=1;
TIM_OC1Init(TIM3, &TIM_OCInitStructure);

TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);
/*******************/

TIM_Cmd(TIM3, ENABLE);