aversive_10-03-12/modules/devices/control_system/filters/biquad/biquad.c File Reference

#include <biquad.h>
#include <string.h>

Go to the source code of this file.

Functions
void	biquad_init (struct biquad_filter *p)
void	biquad_flush_memories (struct biquad_filter *p)
void	biquad_set_numerator_coeffs (struct biquad_filter *p, int16_t b0, int16_t b1, int16_t b2)
void	biquad_set_deniminator_coeffs (struct biquad_filter *p, int16_t a1, int16_t a2)
void	biquad_set_divisor_shifts (struct biquad_filter *p, uint8_t recursive_shift, uint8_t out_shift)
void	biquad_set_series_son (struct biquad_filter *p, struct biquad_filter *son)
int32_t	biquad_do_filter (void *data, int32_t in)

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Function Documentation

int32_t biquad_do_filter	(	void *	data,
		int32_t	in
	)

filter processing, 1 iteration. This function is not protected against writing in the structure while execution is ongoing!

Definition at line 107 of file biquad.c.

References biquad_filter::a1, biquad_filter::a2, biquad_filter::b0, biquad_filter::b1, biquad_filter::b2, biquad_do_filter(), biquad_filter::mem_in_1, biquad_filter::mem_in_2, biquad_filter::mem_out_1, biquad_filter::mem_out_2, biquad_filter::out_shift, gen_regs::p, biquad_filter::recursive_shift, and biquad_filter::son.

Referenced by biquad_do_filter().

void biquad_flush_memories

(

struct biquad_filter *

p

)

this is useful for cleaning the filter memories before a new data set. With this you avoid having old data in the filter memories when beginning to filter a new stream. Can also be used after changing the coefficients, to avoid jumps of the output value.

Definition at line 46 of file biquad.c.

References IRQ_LOCK, IRQ_UNLOCK, biquad_filter::mem_in_1, biquad_filter::mem_in_2, biquad_filter::mem_out_1, and biquad_filter::mem_out_2.

void biquad_init

(

struct biquad_filter *

p

)

init sets an unity filter, as usual

Definition at line 27 of file biquad.c.

References IRQ_LOCK, and IRQ_UNLOCK.

void biquad_set_deniminator_coeffs	(	struct biquad_filter *	p,
		int16_t	a1,
		int16_t	a2
	)

Definition at line 73 of file biquad.c.

References biquad_filter::a1, biquad_filter::a2, IRQ_LOCK, and IRQ_UNLOCK.

void biquad_set_divisor_shifts	(	struct biquad_filter *	p,
		uint8_t	recursive_shift,
		uint8_t	out_shift
	)

Definition at line 84 of file biquad.c.

References IRQ_LOCK, and IRQ_UNLOCK.

void biquad_set_numerator_coeffs	(	struct biquad_filter *	p,
		int16_t	b0,
		int16_t	b1,
		int16_t	b2
	)

accessors to coefficients

Definition at line 61 of file biquad.c.

References biquad_filter::b0, biquad_filter::b1, biquad_filter::b2, IRQ_LOCK, and IRQ_UNLOCK.

void biquad_set_series_son	(	struct biquad_filter *	p,
		struct biquad_filter *	son
	)

this sets a filter to put in series. use as following :

biquad_set_series_son(& filter1, &filter2)

then please use ONLY the filter1. The filter 2 will recursively be called into the filter 1 function : output = biquad_do_filter(& filter1, input);

You can put in series as much biquad filters as you want.

Definition at line 95 of file biquad.c.

References IRQ_LOCK, IRQ_UNLOCK, and biquad_filter::son.