fir_win.h File Reference

#include <stdint.h>

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Defines
#define	FWIN_USE_WINDOW_FUNCTION   1
Typedefs
typedef struct ts_fwin *	p_fwin
Enumerations
enum	te_fir_win_filter_type {   FW_BANDPASS = 0, FW_BANDSTOP, FW_LOWPASS, FW_HIGHPASS,   FW_AVERAGE, FW_NUMBER_OF_FILTER_TYPES }
enum	te_fir_win_window_type {   FW_NONE = 0, FW_HAMMING, FW_HANNING, FW_BLACKMAN,   FW_NUMBER_OF_WINDOW_TYPES }
Functions
p_fwin	fwin_create (double sample_freq, double f_low, double f_high, te_fir_win_filter_type filter_type, te_fir_win_window_type window_type, uint32_t taps)
void	fwin_change_freq (p_fwin fw, double f_low, double f_high)
void	fwin_destroy (p_fwin *fw)
void	fwin_apply (p_fwin fw, double *data, uint32_t size)

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Define Documentation

#define FWIN_USE_WINDOW_FUNCTION   1

Enables (1) or disables (0) Window function support.

Definition at line 27 of file fir_win.h.

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Typedef Documentation

typedef struct ts_fwin* p_fwin

Pointer to Fir Window filter.

Definition at line 56 of file fir_win.h.

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Enumeration Type Documentation

enum te_fir_win_filter_type

FIR filter types.

Enumerator:

FW_BANDPASS	Bandpass filter
FW_BANDSTOP	Bandstop filter Todo: Implement bandstop.
FW_LOWPASS	Lowpass filter Todo: Implement lowpass.
FW_HIGHPASS	Highpass filter Todo: Implement highpass.
FW_AVERAGE	Average filter Sample frequency, low and high cutoff frequency, and window type do not apply.
FW_NUMBER_OF_FILTER_TYPES

Definition at line 30 of file fir_win.h.

enum te_fir_win_window_type

Fir Filter coefficient window.

Enumerator:

FW_NONE
FW_HAMMING
FW_HANNING
FW_BLACKMAN
FW_NUMBER_OF_WINDOW_TYPES

Definition at line 47 of file fir_win.h.

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Function Documentation

void fwin_apply	(	p_fwin	fw,
		double *	data,
		uint32_t	size
	)

Apply the FIR filter to sampled data.

Parameters:

	fw	Pointer to the FIR filter object.
	data	Pointer to the data to be filtered.
	size	Number of data points in data.

Definition at line 190 of file fir_win.c.

References ts_fwin::h, ts_fwin::taps, ts_fwin::z, and ts_fwin::z_state.

Referenced by morse_code().

void fwin_change_freq	(	p_fwin	fw,
		double	f_low,
		double	f_high
	)

Changes the frequency response of an existing FIR filter.

Parameters:

	fw	Pointer to existing FIR filter object.
	f_low	New low frequency cut-off in Hertz.
	f_high	New high frequency cut-off in Hertz.

Definition at line 174 of file fir_win.c.

References ts_fwin::f_high, ts_fwin::f_low, ts_fwin::filter_type, FW_FILTER_FUNCTIONS, and fwin_reapply_window().

Referenced by morse_recompute_filter().

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p_fwin fwin_create	(	double	sample_freq,
		double	f_low,
		double	f_high,
		te_fir_win_filter_type	filter_type,
		te_fir_win_window_type	window_type,
		uint32_t	taps
	)

Creates a FIR filter via the window method.

Parameters:

	sample_freq	Sample frequency in Hertz.
	f_low	Low frequency cut-off in Hertz.
	f_high	High frequency cut-off in Hertz.
	filter_type	Filter type, band-pass, high-pass, low-pass, etc...
	window_type	Window applied to the FIR filter coefficients.
	taps	Number of FIR filter taps (N).

Returns:

Pointer to the FIR filter object.

Definition at line 133 of file fir_win.c.

References DOUBLE_Z_FIR, ts_fwin::f_high, ts_fwin::f_low, ts_fwin::filter_type, FW_FILTER_FUNCTIONS, FW_NUMBER_OF_FILTER_TYPES, fwin_apply_window(), ts_fwin::h, ts_fwin::h_window, ts_fwin::sample_freq, ts_fwin::taps, ts_fwin::window_type, ts_fwin::z, and ts_fwin::z_state.

Referenced by morse_start_threads().

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void fwin_destroy

(

p_fwin *

fw

)

Destroys, and frees all memory from a window FIR filter object.

Parameters:

fw

Pointer to the FIR filter object to be freed.

Definition at line 220 of file fir_win.c.

Referenced by free_all().