50Hz陷波器c代码实现

下面是一个实现50Hz陷波器的C代码示例：

#include <stdio.h>
#include <math.h>

#define PI 3.141592653589793238

void notch_filter_50Hz(double *input, double *output, int len, double fs)
{
    double f0 = 50;
    double Q = 10;
    double w0 = 2 * PI * f0 / fs;
    double alpha = sin(w0) / (2 * Q);
    double a0 = 1 + alpha;
    double a1 = -2 * cos(w0);
    double a2 = 1 - alpha;
    double b0 = 1;
    double b1 = -2 * cos(w0);
    double b2 = 1;

    double x1 = 0, x2 = 0, y1 = 0, y2 = 0;
    for (int i = 0; i < len; i++) {
        double x0 = input[i];
        output[i] = (b0 / a0) * x0 + (b1 / a0) * x1 + (b2 / a0) * x2
                    - (a1 / a0) * y1 - (a2 / a0) * y2;
        x2 = x1;
        x1 = x0;
        y2 = y1;
        y1 = output[i];
    }
}

int main()
{
    int len = 100;
    double input[100];
    double output[100];

    for (int i = 0; i < len; i++) {
        input[i] = sin(2 * PI * i * 50 / 1000) + sin(2 * PI * i * 150 / 1000);
    }

    double fs = 1000;

    notch_filter_50Hz(input, output, len, fs);

    for (int i = 0; i < len; i++) {
        printf("%f\n", output[i]);
    }

    return 0;
}

该代码实现了一个50Hz陷波器，可以过滤掉50Hz的信号。与通用的陷波器代码类似，只需要将中心频率`f0`设置为50Hz即可。在`main`函数中，生成了一个包含50Hz和150Hz信号的合成信号，并对其进行滤波处理。