42 lines
1.1 KiB
C
42 lines
1.1 KiB
C
#include <stdio.h>
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#define N 5 // Number of taps (filter coefficients)
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// Example filter coefficients (simple low-pass averaging filter)
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float coeffs[N] = {
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0.2, 0.2, 0.2, 0.2, 0.2 // Equal weights → moving average filter
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};
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float buffer[N] = {0}; // Circular buffer to store recent inputs
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int bufIndex = 0;
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float fir_filter(float input) {
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buffer[bufIndex] = input;
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float output = 0.0;
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int index = bufIndex;
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// Apply the convolution (dot product of input buffer and coefficients)
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for (int i = 0; i < N; ++i) {
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output += coeffs[i] * buffer[index];
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if (--index < 0)
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index = N - 1; // Wrap around circular buffer
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}
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bufIndex = (bufIndex + 1) % N;
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return output;
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}
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int main() {
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float noisy_signal[] = {1, 2, 3, 2,
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100, 3, 2, 1}; // A spike in the middle (100)
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int len = sizeof(noisy_signal) / sizeof(float);
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printf("Filtered output:\n");
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for (int i = 0; i < len; ++i) {
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float filtered = fir_filter(noisy_signal[i]);
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printf("%.2f\n", filtered);
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}
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return 0;
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}
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