FIR算法C语言实现

（1）高通与低通系数

#if LOWPASS

float32 B [FILTER_LEN] = {0.0625L, 0.25L, 0.375L, 0.25L, 0.0625L};

#elif HIGHPASS

float32 B [FILTER_LEN] = {0.0625L, -0.25L, 0.375L, -0.25L, 0.0625L};

#endif

（2）算法实现

FILTER_LEN = 5

变量定义：

float32 fir[FILTER_LEN];

float32 fir_temp,Y,Y_OUT;

FIR计算：

fir[0] = AdcResult.ADCRESULT1;//取ADC值

fir_temp = fir[4];

Y = B[4] * fir_temp;//系数乘法计算

fir[4] = fir[3];//移位

fir_temp = fir[3];

Y = Y + B[3] * fir_temp; //累加

fir[3] = fir[2];

fir_temp = fir[2];

Y = Y + B[2] * fir_temp;

fir[2] = fir[1];

fir_temp = fir[1];

Y = Y + B[1] * fir_temp;

fir[1] = fir[0];

fir_temp = fir[0];

Y = Y + B[0] * fir_temp;

Y_OUT = Y; //FIR输出