普中51-单核-A2
STC89C52
Keil uVision V5.29.0.0
PK51 Prof.Developers Kit Version:9.60.0.0
串口示波器：Vofa+ 1.3.10

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网上查到的滑动平均值滤波器在计算平均值的时候还要再for累加一遍，这太浪费时间了，在一些性能较拉跨的单片机上是难以接受的。我进行了如下改进：

源码

Filter.c

#include "stdint.h"
#include "Filter.h"Sliding_Mean_Filter Example_Filter = {{0}, 0, 0, 0};void Sliding_Mean_Filter_Calc(Sliding_Mean_Filter *filter, double Data)
{filter->sum -= filter->Filter_Buffer[filter->id];	//减去最旧的数filter->sum += Data;								//加进最新的数filter->Filter_Buffer[filter->id] = Data;			//将最新的数覆盖最旧的数filter->average = filter->sum / Sliding_Mean_Filter_Buffer_Size;	//求均值if(++filter->id == Sliding_Mean_Filter_Buffer_Size)filter->id = 0;
}

Filter.h

#ifndef Filter_H_
#define Filter_H_ #define Sliding_Mean_Filter_Buffer_Size 50typedef struct
{double Filter_Buffer[Sliding_Mean_Filter_Buffer_Size];uint16_t id;double sum;double average;
}Sliding_Mean_Filter;void Sliding_Mean_Filter_Calc(Sliding_Mean_Filter *filter, double Data);extern Sliding_Mean_Filter Example_Filter;#endif

使用

Data为喂入的数据，结果在Example_Filter.average里

Sliding_Mean_Filter_Calc(&Example_Filter, Data);

效果

用51单片机测试，晶振频率为11.0592MHz，6T模式，对随机数进行滤波
滤波器的数组大小为50：
可以看到，随机数的均值为0.5，合理！


滤波器的数组大小为10：

滤波器的数组大小为25：