c语言设计低通滤波器（测试通过）

1、利用matlab中的fdatool设计滤波器，然后导出为c header也就是系数

2、编写头文件

#ifndef __FILTER_H__
#define __FILTER_H__

#include 
#include 
// #define FRAME_READ_LENGTH   (256)
#define FRAME_READ_LENGTH   (20000)
#define Factor 2.0*3.1415926/100000.0
#define FIR_FILTER_LENGTH 41


void process(float *x,float *y,int N);

#endif

2、编写函数文件

#include "filter.h"

float state[FRAME_READ_LENGTH+1]={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
float FIR_COFFES[FIR_FILTER_LENGTH]=
{  
   0.001075295550174,0.0004607092771574,-0.0006249377423234,-0.002090047702952,
  -0.003308272540335,-0.003120062463785,-0.0004618791563568, 0.004600933630625,
    0.01011810524146,  0.01253213617422, 0.008282768041107, -0.00378906797618,
   -0.02047676398223, -0.03403584021207,  -0.0344694727458, -0.01370238068746,
    0.03008542081049,   0.0901066613135,   0.1520726052581,   0.1987175833049,
     0.2160530132155,   0.19871758